Dissertations / Theses: 'Cotton – Insect control and insecticides'

1

Watson, T. F., and Clay Mullis. "Effect of Various Insecticides on Pink Bollworm Control." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204083.

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2

Kerns, David L., and Tony Tellez. "Efficacy of Experimental Insecticides for Whitefly Control in Cotton, 1996." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210365.

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Experimental insecticides were evaluated for control of sweet potato whiteflies relative to a commercial standard in cotton. Ni-25 provided excellent whitefly control and was equivalent to the commercial standard (Knack followed by Danitol + Orthene). Fenoxycarb + pymetrozine provided goodwhitefly control but seemed to require 2 sequential applications before control was equivalent to Ni-25. Diofenolan + pymetrozine appeared to be a slightly weaker treatment, but still provided acceptable whitefly control.

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3

Baker, Paul B., and Tasha M. Brew. "Pest Control Advisors' Recommendations for Cotton Insecticides: A Historical Review." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/204514.

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A survey of agricultural pest control professionals showed that certain compounds have consistently been recommended to control cotton pests for more than 40 years. Over that same period, the number of preferred materials available for recommendation has greatly increased. Other trends are toward greater use of compounds using lower application rates and biological insecticides.

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4

Kerns, David L., and Tony Tellez. "Efficacy of Experimental Insecticides for Whitefly Control in Cotton, 1997." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210376.

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Whitefly populations in this trial were abnormally low relative to previous years experiences. M-25 provided excellent whitefly control and was equivalent to the commercial standard (Knack followed by Danitol + Orthene). However, there is some question concerning its adult activity late in the season, when it appeared to be weaker than Danitol + Orthene and Capture + Curacron. At low whitefly populations Thiodan tank -mixed with Knack appeared to extend control over Knack alone.

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5

Chu, C. C., T. J. Henneberry, and D. H. Akey. "Sweetpotato Whitefly (Bemisia tabaci Gennadius) Control: Field Studies with Insecticides on Cotton in the Imperial Valley, CA." College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/209567.

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Insecticides and insecticide mixtures were evaluated for sweetpotato whitefly (Bemisia tabaci Gennadius) control on cotton in the Imperial Valley, CA in 1992. Seasonal average number of large immatures was 1.6/cm² leaf disk from plots treated with a mixture of Danitol and Orthene as compared to 4. 5/cm² on leaf disks from untreated control plots. Lint yield was 1232 lbs/ac compared to other treatments which ranged from 551 to 976 lbs /ac.

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6

Kerns, David L., and Tony Tellez. "Efficacy of Experimental Insecticides for Insect Control in Cotton Grown in the Low Desert Region of Arizona, 1997." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210389.

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Experimental insecticides were evaluated for control of lygus bugs relative to commercial standards in cotton. These products were also evaluated for activity towards whiteflies and pink bollworms. CGA293343 was not effective when used as a side-dress material at layby, but was effective toward whiteflies, and towards lygus at higher foliar rates. Regent, Vydate and Mustang + Thiodan were highly effective for lygus control, while EXP61096A and Mustang alone performed poorly. Against whiteflies, CGA293343, Acetamiprid, and Mustang + Thiodan were most efficacious, while Mustang alone and with Thiodan were most effective towards pink bollworms.

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7

Subramaniam, V. R. "Cloning, characterisation and sequence comparison of sodium channel genes from Pyrethroid-resistant and susceptible strains of Heliothis virescens (Fab.) (Lepidoptera: Noctuidae)." Thesis, University of Reading, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360077.

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8

Kerns, David L., and Tony Tellez. "Efficacy of Insecticides for Pink Bollworm and Cotton Leaf Perforator Control in Cotton Grown in the Low Desert Region of Arizona, 1997." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210359.

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Neither Tracer nor Proclaim appeared to be effective pink bollworm materials whether applied at day or night. However against cotton leafperforator, both Tracer and Proclaim provided sufficient control. Although all three formulations of Karate equally provided statistically significant pink bollworm control, it was not commercially acceptable. Shortening the spray interval from 7 to 4 days may have helped alleviate this problem. None of the Karate formulations evaluated appeared to offer outstanding cotton leafperforator control.

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9

Umeda, K., D. MacNeil, and D. Roberts. "New Insecticides for Diamondback Moth Control in Cabbage." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/219999.

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At 3 days after the first application, RH-2485, Success, Proclaim, Avaunt, and Larvin reduced the total number of diamondback moth (DBM) larvae to less than 2.0 larvae per 10 plants compared to the untreated that had 7.0 larvae/10 plants. Alert, Kryocide, and S-1812 treated cabbage exhibited 4.0 to 5.0 larvae/10 plants and Lannate was intermediate with 2.7 total larvae/10 plants. Following a second application, Success and Proclaim completely controlled DBM for one week. Success, Proclaim, Alert, and Larvin continued to offer very good control of DBM for two weeks after the second application. S-1812 performed similarly to Lannate.

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10

Umeda, K., D. MacNeil, D. Roberts, and N. Lund. "Evaluation of Foliar Insecticides for Whitefly Control in Cantaloupes." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/219996.

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The pyrethroid insecticides esfenvalerate (Asana®), bifenthrin (Capture®), or fenpropathrin (Danitol®) combined with endosulfan effectively reduced whitefly (WF, Bemisia argentifolii) counts at 1 week after treatment (WAT) following each of five applications. Asana, Capture, or Danitol combined with endosulfan effectively reduced WF counts at 1 WAT following each of five applications. Danitol treated melons exhibited fewer adult WF compared to Asana or Capture at most of the rating dates at 6 days after treatment (DAT) of each of the applications and also at 11 DAT of the last application. A single application of buprofezin (Applaud®) treatments or pymetrozine (Fulfill®) effectively reduced WF nymphs for 18 to 24 DAT and adults were reduced for 18 DAT. Fulfill exhibited a rate response where the higher rate reduced WF counts more than the lower rate.

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11

Ellsworth, Peter C., Brian Deeter, and Mike Whitlow. "EUP Evaluation of a Novel Insecticide for Lygus Control." College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/197261.

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Lygus became the number one pest of cotton in 1998 with statewide losses of over $16 million in spite of individual costs to the grower of over $55/A for control. Selective technologies for whitefly and pink bollworm control reduce the number of broad spectrum sprays that incidentally control Lygus. Control of Lygus depends mainly on just two related chemical classes of insecticides, organophosphates and carbamates. Over reliance on such a limited diversity of chemical controls increases the risk of resistance. Further, FQPA threatens the future availability of many of our main stay chemical controls. The study reported here sought to investigate the commercial suitability of a new compound, Regent®, for the control of Lygus. This novel mode of action represents one of the few potential new tools under development for Lygus management. Under a federal Emergency Use Permit (EUP), Regent was tested against two standards of Lygus control (Orthene® and Vydate®) and an untreated check. In a test of unusually high Lygus densities, Regent provided excellent control of small (instars 1–3) and large (instars 4–5) Lygus nymphs and may provide marginally better control of adults than current standards. None of the tested agents provided quick control or knockdown of adults. Rather, adult levels were reduced over time, most likely as a result of prevention of the development of new adults via nymphal control. All three materials protected cotton producing yields significantly higher than the check. The Orthene treatment had the highest yield, though not significantly higher than the Regent treatment which was effectively sprayed one less time than the other compounds.

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12

Knowles, Tim C., Neil Bushong, and Jim Lloyd. "Systemic Insecticide Applications at Planting for Early Season Thrips Control." College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/197277.

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Temik 15G (6 lbs/acre) or Thimet 20G (8.2 lbs/acre) granular insecticides were applied to 40 inch rows in furrow at planting to cotton growing in Parker Valley, AZ. Moderate thrips pressure (0.5-1.5 thrips/plant) was experienced for the first eight weeks after planting and granular insecticide application. Temik provided better thrips control than Thimet for the first seven weeks after planting this study. Thrips control was similar for the two insecticides beyond eight weeks after planting. Temik application resulted in higher fruit retention levels measured up to 10 weeks after planting, compared to Thimet. However, fruit retention levels measured from 12 to 16 weeks after planting were similar for both Temik and Thimet when cotton plants compensated for early season square losses caused by thrips feeding.

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13

Knowles, Tim C., Mike Keavy, and Victor Wakimoto. "Systemic Insecticide Applications at Planting and First Square in Bt Cotton for Early Season Insect Control - La Paz and Mohave Counties." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210390.

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Temik 15G (6 lbs/acre) and Thimet 20G (7.5 lbs/acre) granular insecticides were applied in furrow at planting and compared to an untreated check in two experiments in Parker Valley and Mohave Valley, AZ. At first square each of these main plots was split in half and either Temik 15G or DiSyston 8L was sidedressed to each subplot and compared to an untreated strip. Thrips and lygus counts were taken at weekly or biweekly intervals and plant response measured from the 2 or 3 leaf stage through layby. Under the thrips pressure experienced in these two experiments (0.5-1.5/plant), Temik and Thimet at planting provided similar and adequate protection from thrips for up to 7 weeks following application. Temik 15G sidressed at 14 lbs/acre at first square provided lygus bug control for up to 42 days following application under light lygus bug pressure (5-15/100 sweeps). Di- Syston 8L sidedressed at 1 qt/acre at first square provided lygus bug control for 35 days following application under moderate lygus bug pressure (15-20/100 sweeps). Under the conditions of this study, systemic insecticide applications at planting and first square did not increase cotton lint yields of insecticide treated Bt cotton plots, compared to the untreated control plots.

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14

Jech, L. E., and S. H. Husman. "Correlation between Early Season Insecticide Control of Pink Bollworm and Other Pests and Subsequent Whitefly Applications near Gila Bend, AZ, 1997." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210360.

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Cotton pesticide application histories in the Gila Basin were followed from 27 April through 20 September. The main interest was the effect of early season applications to control pink bollworm, Pectinophora gossypiella, and other pests on subsequent whitefly applications. Categories explored include, transgenic and non transgenic cotton, planting dates, and location within the valley. Regression analysis shows a significant effect due to the early season control for either P. gossypiella, or other pests (P > 0.009) but lower for them together (P > 0.026). Early applications for either PBW or other pest resulted in increased application for whitefly.

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15

Dennehy, T. J., J. E. Russell, L. Antilla, and M. Whitlow. "New Insights Regarding Estimating Lygus Susceptibility to Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210378.

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Lygus susceptibility was found to vary widely from year to year, from region to region and, for some insecticides, even within the season. It is for this reason that producers need current, region-specific recommendations in order to determine which insecticides are most effective at their locale. Our studies were intended to improve understanding of the reliability of glass vial bioassays for estimating efficacy of insecticides used against lygus bugs. Results show that the standard glass vial method offers considerable promise for detecting differences in susceptibility of lygus to some, but not all, insecticides. However, mortality in vial bioassays did not serve as a reliable predictor of the relative toxicity of residues of five insecticides in field treatments. Therefore, field evaluations of insecticide efficacy continue to be essential for selecting the insecticides that provide the best control of lygus. Once the most effective materials are selected from field trial results, bioassays can be used to efficiently monitor changes in population susceptibility to these insecticides. Additional new insights provided by our studies are that efficacy of residues of insecticides declined rapidly, such that after three days all insecticides caused very little mortality to adult lygus bugs. Lastly, we found a marked difference between residual and direct contact toxicity of the five insecticides evaluated. Even the insecticide treatments that resulted in relatively low toxicity in residual exposure tests killed 95-100% of lygus bugs that they contacted directly under field conditions. This finding indicates that producers experiencing severe problems with lygus control would be well advised to improve insecticide coverage.

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16

Watson, Theo F., and Suzanne E. Kelly. "Status of Pink Bollworm Resistance to Insecticides in Arizona." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208371.

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Populations of pink bollworm. Pectinophora gossypiella (Saunders), from Yuma, Casa Grande, Marana and Safford were compared with that of a susceptible laboratory (USDA) strain relative to their susceptibility to permethrin. A limited comparison was made with azinphosmethyl. All field strains were significantly more tolerant to permethrin than was the USDA susceptible strain. A comparison of the USDA and Yuma strains using azinphosmethyl indicated no difference in susceptibility between the laboratory and field strains.

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17

Russell, J. E., T. J. Dennehy, L. Antilla, M. Whitlow, R. Webb, and J. Pacheco. "Lygus Bugs in Arizona Regain Susceptibility to Key Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/211106.

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Adult lygus bugs, Lygus hesperus (Knight), were collected from alfalfa fields in 22 different cotton producing areas of Arizona. A standardized, glass vial method was used to estimate susceptibility of the collected populations to the pyrethroid insecticide Captures (bifenthrin) and the organophosphate Orthene® (acephate). Large differences were recorded in susceptibility of Arizona populations to both insecticides. The most susceptible lygus populations continue to be found in the eastern areas of the state and the least susceptible in central Arizona. Lygus from throughout the state were substantially more susceptible to Capture and Orthene in 1996 than in 1995. Lygus bioassayed repeatedly from the same locations in 1996 exhibited moderate-to-small seasonal variability in susceptibility to Capture. However, some of the same populations varied widely in susceptibility to Orthene in 1996. The large changes in susceptibility to Orthene were attributed to episodic movements of lygus from other hosts. Eleven insecticides were evaluated against populations most and least susceptible to Capture and Orthene to identify promising candidates for future lygus field trials. A Safford population was substantially more susceptible than a Maricopa population to Admire®, Curacron®, Cygon®, Malathion® and Vydate®. Most surprising was the greatly reduced susceptibility to Admire of the Maricopa population. The older insecticides Bidrin®, Lannate®, Monitor ®, Naled®, Ovasyn® and Thiodan® were quite similar in toxicity to both the Safford and Maricopa populations and therefore are good candidates for further field evaluations to judge their merit for inclusion in lygus insecticide rotations. Bioassay results were related to field performance of four insecticides in a field trial conducted in Central Arizona. Findings showed that the two insecticides that caused the lowest mortality in vial bioassays, Orthene and Vydate, resulted in the greatest suppression of lygus in the field. These findings underscore that the absolute level of mortality observed in bioassays should not be assumed to reflect relative efficacy in the field. It also confirms that Orthene and Vydate continue to be good choices for lygus control, even in Central Arizona where populations are decidedly less susceptible to these insecticides. We have demonstrated that the adult vial bioassay provides a reliable method for measuring differences between Arizona lygus populations in susceptibility to a broad range of conventional insecticides. We found the method sufficiently sensitive to repeatedly detect significant within-season and regional differences in lygus susceptibility. These new insights will allow us to better manage the insecticides used in Arizona to control this important pest.

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Dennehy, T. J., L. III Williams, X. Li, M. Wigert, and E. Birdwell. "Status of Whitefly Resistance to Insecticides in Arizona Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/211109.

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We summarize a whitefly resistance crisis that culminated in 1995 in Arizona cotton and that prompted the development of an integrated resistance management strategy. The strategy incorporated two new major elements: once-per-year use of the insect growth regulators (IGRs), Knack® (pyriproxyfen) and Applaud® (buprofezin), and measures to delay use of pyrethroids for as long into the growing season as possible. A three-stage chemical use recommendation was formulated comprising IGRs (Stage I), other non-pyrethroid insecticides (Stage II), and synergized pyrethroid insecticides (Stage III). Results from use of the strategy in the 1996 season were very promising. Insecticide use for control of whiteflies was reduced substantially where IGRs were used. Statewide monitoring of whitefly susceptibility to key insecticides revealed significant reductions in resistance to synergized pyrethroids as well as to non-pyrethroid insecticides. Resistance to Danitol® + Orthene® was shown to decline sharply from the end of the 1995 season to early in the 1996 season at the Maricopa Agricultural Center. Use of Stage I materials (Knack® and Applaud®) and specific Stage II (non-pyrethroid) insecticides in 1996 resulted in only small reductions in susceptibility to synergized pyrethroids. However, one application of Danitol® + Orthene® yielded a large increase in resistance. These findings confirmed the value of the newly formulated resistance management strategy and indicated that resistance to the synergized pyrethroids can be managed if these insecticides are used sparingly. Additionally, evidence was obtained of collateral resistance buildup and decline in lygus bugs and whiteflies. Substantially reduced susceptibility of lygus bugs was documented in 1995, relative to 1994, coinciding with elevated insecticide use to control resistant whiteflies. Implementation of the 1996 whitefly resistance management program was correlated with increased lygus bug susceptiblity to the insecticides Orthene® and Capture® at most locations monitored throughout Arizona.

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19

Simmons, A. L., and T. J. Dennehy. "Contrasts of Three Insecticides Resistance Monitoring Methods for Whitefly." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210913.

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Three resistance monitoring methods were tested to evaluate their relative reliability, discriminating ability, convenience, and practicality for monitoring insecticide resistance in Arizona whiteflies. Adult whiteflies were collected from the field and tested in the laboratory with three methods: leaf disk, sticky trap, and vial. Each method was evaluated against two populations divergent in susceptibility using a mixture of Danitol® + Orthene® and two single chemicals, Thiodan® and Danitol®. The Yuma population was relatively susceptible and the Gila River Basin population highly resistant. Correlations of field efficacy and leaf disk bioassays were conducted with the Yuma population and a comparatively resistant Maricopa population. At each location egg, immature, and adult whitefly densities were monitored before and after Danitol® + Orthene® treatments and resistance estimates were also monitored in the populations using leaf disk bioassays. Our results illustrated that the leaf disk method had the greatest discriminating ability between susceptible and resistant populations. The results also indicated that the vial method was the most practical, and that the sticky trap method was good at discriminating between populations that have large differences in susceptibility. The field efficacy trials indicated results from leaf disk assays reflected what had occurred in the field.

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20

Hutchinson, Bill, Bud Beasley, and Tom Henneberry. "Pink Bollworm Egg-Larval Survivorship in Cotton Treated with Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 1988. http://hdl.handle.net/10150/204504.

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Pink bollworm egg -larval survivorship in insecticide -treated fields averaged (± SE) 19.8% (± 2.3) for the F2 and F3 generations developing during the primary boll producing time of the year (July and August). These observations have been useful in developing a simulation model of pink bollworm population dynamics.

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21

Ellsworth, P. C., and D. L. Meade. "Performance of Selected Insecticides Against the Sweetpotato Whitefly and Cotton Aphid." College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/209577.

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Seven insecticides were evaluated in nine treatment combinations for efficacy against the sweetpotato whitefly (SPWF) and the cotton aphid (CA). Five different classes of chemistry were represented by these compounds, which were compared to an untreated check. The infestation was characterized as severe (> 300 SPWFs/sq. in.) and included a substantial number of CAs at the beginning of the evaluation ( >90 /leaf). Three applications were made in August after the onset of "stickiness." For SPWFs, three treatments compared favorably with the check, but only after three applications Orthene +Danitol, Capture alone, and Capture +Ovasyn. Intermediate control was achieved with Endosulfan +Ovasen. Rankingsfor CA control were dissimilar with Vvdate +Asana, Endosulfan +Ovasen, and Ovasen alone consistently performing better than the check. Vvdate alone, Endosulfan alone, and Orthene +Danitol were intermediate in CA control, but also significantly different from the check. Capture alone and Capture+Ovasyn which performed well for SPWF control was not efficacious against CAs. Indeed the two single pyrethroid treatments (Capture: Asana) failed to achieve any degree of CA control.

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22

Williams, Livy III, Timothy J. Denney, and John C. Palumbo. "Can Resistance to Chloronicotynl Insecticides be Averted in Arizona Field Crops?" College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210363.

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A resistance management program was initiated in Arizona in 1995, the initial goal of which was to sustain the efficacy of imidacloprid (Admire®) against Bemisia in vegetable crops. Due to the anticipated registration of additional chloronicotinyl (and related neonicotinyl) insecticides in Arizona, project objectives were subsequently broadened to address management of this entire class of insecticides in Arizona field crops. Results from three years of statewide monitoring of whiteflies from cotton indicated that whitefly populations in Arizona have become significantly less susceptible to imidacloprid in each of the past two years and significant geographical differences were described. However, no evidence was found of reduced field performance of imidacloprid in vegetables. Additionally, laboratory studies subjecting Arizona whiteflies to selection with imidacloprid did not increase levels of resistance beyond those occurring in the field. A study exploring the influence of cropping system differences on imidacloprid use (Admire® and Provado®) revealed no major differences in susceptibility to this insecticide between populations of whiteflies in central and southwestern Arizona. However, distinct seasonal shifts to lower susceptibility from 1996 to 1997 were observed in the Dome Valley of southwestern Arizona. Susceptibility of Arizona whitefly populations to imidacloprid was highly correlated with susceptibility to acetamiprid but was unrelated to susceptibility to CGA-293343. There is an urgent need to harmonize chemical use and resistance management efforts in Arizona cotton, vegetables and melons to avoid conflicts resulting from movement of pests between crops.

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Jech, L. E., S. H. Husman, P. C. Ellsworth, and J. W. Diehl. "Whitefly Control Using Insect Growth Regulators." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/211091.

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Management of whiteflies with two insect growth regulators was compared with standard practices in grower managed cotton near Gila Bend, AZ. The IGRs, Knack (pyriproxyfen) and Applaud (buprofezin) were tested in a randomized complete block experiment with seven replicates. University ofArizona recommendations were followed to time insecticide applications. Following IGR applications, the nymphal populations remained near or below action thresholds (≤ 0.5-1.0 large nymphs per 3.88 cm² disk) from early August through early October. The standard practices treatments maintained the nymphal population through only early September, when populations sharply increased IGR treatments resulted in adult populations below University of Arizona action thresholds nearly as long as the nymphs. There was an adult population peak that followed a nymphal peak near the middle of September.

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24

Tyler, Ray, Edith DeRosa, Lee J. Clark, and Leon Moore. "Early Insect Control in Cotton, Greenlee County." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219791.

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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.
Cotton was treated at the pinhead square stage with Orthene to prevent boll shed caused by thrips and Lygus. Yield results showed no statistically significant differences, even though yield trends indicated a decrease in the treated plots compared to the check. Severe pressure from Heliothus later in the season and the yield trends would indicate that the insecticide treatment effect on the beneficial insects was more important than its effect on thrips and Lygus.

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Umeda, K., J. Murrieta, and D. Stewart. "Lepidopterous Insect Pest Control with New Insecticides in Cabbage." College of Agriculture, University of Arizona (Tucson, AZ), 1997. http://hdl.handle.net/10150/221641.

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Four experimental insecticides being developed for lepidopterous insect control in vegetable crops were applied on cabbage and demonstrated efficacy against cabbage looper (Trichoplusia ni, CL). Chlorfenapyr (Alert®), tebufenozide (Confirm®), spinosad (Success®), and emamectin- benzoate (Proclaim®) reduced the number of larger cabbage loopers following multiple applications. The experimental insecticides were comparable or superior to the commercially available standard treatments of thiodicarb (Larvin®), methomyl (Lannate®), or cryolite (Kryocide®). Evaluations at 7 days after treatment (DAT) showed that Success controlled CL so that no medium to large -sized larvae were observed. Alert, Confirm, and Proclaim were highly effective and less than 0.3 CL/plant were detected. The untreated cabbage had 0.5 to 1.1 CL/plant that were medium to large-sized at various observation dates.

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Dennehy, Timothy J., Livey III Williams, Xiaohua Li, and Monika Wigert. "1997 Season Update on Resistance of Arizona Whiteflies to Synergized Pyrethroid and Select Non-Pyrethroid Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210362.

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A whitefly resistance crisis in Arizona in 1995 prompted the development of a resistance management strategy in 1996 that recommended maximal once per season use of two insect growth regulators, pyriproxyfen (Knack®) and buprofezin (Applaud®), and limited and delayed use of synergized pyrethroid insecticides in cotton. Statewide monitoring of whitefly resistance has shown that implementation of this strategy has substantially reduced whitefly resistance to the synergized pyrethroids and has also resulted in increased susceptibility to key non pyrethroid insecticides. Having benefited from two years of success with this strategy, the Arizona cotton industry now faces the question of whether it can be sustained as pyriproxyfen and buprofezin gain additional registrations for use against whiteflies in vegetables, melons and glasshouse crops.

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27

Sivasupramaniam, S., S. E. Kelly, D. Cross, J. Brown, and T. F. Watson. "Use of Treated-vial Technique to Determine Efficacy of Several Insecticides against the Sweetpotato Whitefly, Bemisia tabaci (Gennad.)." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/208652.

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A treated -vial technique was used to bioassay insecticide susceptibility of sweet potato whitefly populatons occurring on different hosts and at different locations in southern Arizona. All insecticides tested proved to be efficacious against the sweetpotato whitefly. Combinations improved efficacy, for example, Orthene to Danitol and DEF to Baythroid. Three important factors appeared to affect efficacy: 1) geographic site; 2) host plant of SPWF; and, 3) time of season. Further detailed experimentation needs to be done to elucidate the reasons for this.

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Umeda, K., C. Fredman, and R. Fredman. "Insecticides for Whitefly Control in Cantaloupes." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/214751.

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Several experimental insecticide treatment combinations were evaluated and demonstrated very good efficacy against Bemisia argentifolii [silverleaf whitefly (WF) also known as sweetpotato WF, B. tabaci]. Adults and immatures were most effectively reduced compared to the untreated check by pyriproxyfen (S-71639, Valent) treatments and fenpropathrin (Danitol®) plus acephate (Orthene®). CGA-215944 (Ciba) plus fenoxycarb (Ciba) treatments compared favorably with many of the pyrethroid combination treatments. Registered products esfenvalerate (Asana®), endosulfan (Thiodan®), cypermethrin (Ammo®), naled (Dibrom®), and oxydemeton-methyl (Metasystox-R®) complemented many of the combination treatments to reduce WF relative to the untreated check

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Umeda, Kai, and Chris Fredman. "Evaluation of Insecticides for Lepidopterous Insect Pest Control in Cabbage." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/214747.

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Experimental insecticides MK-244 (Merck), Alert (AC 303630, Cyanamid), and Confirm (RH-5992, Rohm and Haas) demonstrated very good efficacy in reducing the lepidopterous pests including plutell4 xylostella (diamondback moth, DBM) and Tricoplusia at (cabbage looper, CL) in cabbage. The total number of small, medium, and large DBM larvae for all treatments was lower than the untreated at most rating dates. The experimental insecticides compared favorably with commercially available products Lannate®, Larvin®, and Kryocide®.

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Ellsworth, Peter C., and Donna L. Meade. "Validity of the Pinhead Square Treatment Program for Pink Bollworm Suppression and Impact of Several Insecticides on Arthropod Fauna in Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209638.

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A limited chemical control tactic known as pinhead square treatment has gained recent Favor as a component of pink bollworm population management. The strategy has economic and ecologic goals of using reduced insecticides early in the season (to include lower rates, half the acreage, and less potent chemistry) in order to reduce later season risk of pink bollworm infestations. This strategy also depends in part on the cultural tactic which results in "suicidal emergence" of overwintering pink bollworms through optimal planting date management. The combination of these tactics has been used in the past to overcome boll weevil populations area-wide. This study is focused on the evaluation of this system as a basis for pink bollworm suppression. Though only preliminary is presented here, it is clear that there are numerous insects impacted by this practice which interact in complex ways to influence pest populations of all kinds. Furthermore, the fate of such a practice in any production system is also influenced by the specific chemical agent used. This experiment details the use of four different classes of insecticide chemistry as well as one bioinsecticide. The experiment has been duplicated in 1993; however, only 1992 data are shown here.

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Dennehy, T. J., and T. J. Russell. "Susceptibility of Lygus Bug Populations in Arizona to Acephate (Orthene®) and Bifenthrin (Capture®), with Related Contrasts of Other Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210912.

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Adult lygus bugs, Lygus hesperus (Knight), were collected from alfalfa fields in 11 different cotton producing areas of Arizona. A standardized glass vial method was used to estimate susceptibility of the collected populations to the organophosphate insecticide, acephate (Orthene®), and the pyrethroid bifenthrin (Capture®). Overall, lygus from throughout the state were significantly less susceptible to acephate and bifenthrin in 1995, than in 1994. Resistance of lygus to acephate continues to be widespread and intense, but not uniform in Arizona. In 1995, all populations possessed individuals capable of surviving exposure to vial treatments of 10,000 μg/ml acephate. Lygus bugs from Safford and Maricopa represented the most and least susceptible populations, respectively, to both acephate and bifenthrin. These two populations were tested for susceptibility to nine other insecticides: aldiaarb (Temik®), dimethoate (Gowan Dimethoate E267®), endosulfan (Gowan Endosulfan 3EC®), imidacloprid (Admire 2F®), malathion (Gowan Malathion 8®), methamidophos (Monitor 4®®), methomyl (Lannate LV®), oxamyl (Vydate 3.77L®), apt oxydemeton- methyl (Metasystox-R SC®). The Maricopa population was significantly less susceptible to six of these insecticides. Our findings support the hypothesis that the intensive use of pyrethroid and organophosphate insecticides for whitefly control in cotton has selected for resistance in lygus. This result portends increased problems with lygus control in the future, points to the need for developing new tools for controlling lygus bugs in Arizona cotton, and underscores the urgent need to find alternatives to the current heavy reliance on insecticides for managing whiteflies in cotton.

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Li, Yongsheng, Timothy J. Dennehy, Xiaohua Li, and Monika E. Wigert. "Susceptibility of Arizona Whiteflies to Chloronicotinyl Insecticides and IRGs: New Developments in the 1999 Season." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/197518.

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Whiteflies are serious pests of cotton, melons, and winter vegetables in Arizona’s low deserts. Successful management of whiteflies requires an integrated approach, a critical element of which is routine pest monitoring. In this paper we report findings of our 1999 investigations of resistance of Arizona whiteflies to insect growth regulators (IGRs) and chloronicotinyl insecticides. Whiteflies collected from cotton fields, melon fields and greenhouses were tested for susceptibility to imidacloprid (Admire/Provado), and two other chloronicotinyl insecticides, acetamiprid and thiamethoxam, and to two insect growth regulators (IGRs), buprofezin (Applaud) and pyriproxyfen (Knack). Contrasts of 1999 and 1998 results indicated increased susceptibilities, on average, to both imidacloprid and buprofezin of whiteflies collected from cotton. A cropping system study showed that whiteflies collected from spring melons had significantly lower susceptibility to imidacloprid than those collected from cotton or fall melons. The opposite was found for pyriproxyfen, to which whiteflies from cotton and fall melons had lower susceptibility than those from spring melons. As in 1998, whiteflies with reduced susceptibility to imidacloprid continue to be found in certain locations, particularly in spring melon fields and greenhouses. Results of our laboratory bioassays on susceptibility of Arizona whiteflies to chloronicotinyl insecticides provided evidence of a low order cross-resistance between imidacloprid, acetamiprid and thiamethoxam. Monitoring in 1999 provided the first evidence of reduced susceptibility of Arizona whiteflies to pyriproxyfen.

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Chu, C. C., and T. J. Henneberry. "Chemical Control Studies of Silverleaf Whitefly Control." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210866.

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Chemical control studies for silverleaf whitefly, Bemisia argentifolii Bellows and Perring, control on cotton showed that fenpropathrin-acephate, fenpropathrin-endosulfan, and endosulfan-bifenthrin mixtures gave adequate control and increased cotton yields were obtained as compared within untreated cottons. Pyriproxyfen, applied biweekly or alternated with fenpropathrin-acephate, Nicotiana, and a fenpropathrin-mycotrol mixture also gave effective control.

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Bartlett, A. C., L. J. Lewis, and B. A. Hunter. "Control of the Sweetpotato Whitefly by Insect Growth Regulators." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208356.

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Two newly developed insect growth regulators were tested at two dose levels for control of the sweetpotato whitefly on cotton. The two chemicals showed some promise for control although the dose rate and application schedules were not optimal and plot sizes were too small to show a decrease in cotton stickiness or sugar content due to the treatments. In these tests a chitin synthesis inhibitor was more effective in controlling immature stages than a juvenile hormone mimic.

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35

Umeda, K., and B. Strickland. "S-1812 Lepidopterous Insect Pest Control in Broccoli Study." College of Agriculture, University of Arizona (Tucson, AZ), 1999. http://hdl.handle.net/10150/219968.

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A single application of S-1812 (Valent) at 0.15 and 0.20 lb AI/A effectively reduced Plutella xylostella (diamondback moth, DBM) in broccoli compared to the untreated check. S-1812 at 0.15 lb AI/A performed similar to thiodicarb (Larvin) at 1.0 lb AI/A. S-1812 significantly reduced the DBM at 5 days after treatment (DAT) and control was effective for up to 14 DAT. S-1812 was less effective against Trichoplusia ni (cabbage looper, CL) compared to DBM control efficacy or Larvin. S-1812 reduced the development of small CL to larger sized larvae.

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Umeda, Kai, and Chris Fredman. "Evaluation of Insecticides for Aphid Control in Cabbage." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/214743.

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Experimental insecticides CGA-215944 (Ciba), pyriproxyfen (S-71639, Valent), and RH-7988 (Rohm and Haas) demonstrated very good efficacy in reducing the aphid population in cabbage. Fipronil (Rhone-Poulenc) was not as effective in controlling the aphids relative to the other treatments. Acephate (Orthene®), chlorpyrifos (Lorsban™), and naled (Dibrom®) were highly effective relative to the untreated check.

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37

Dennehy, T. J., Livy III Williams, June S. Russell, Xiaohua Li, and Monika Wigert. "Monitoring and Management of Whitefly Resistance to Insecticides in Arizona." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210911.

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Monitoring of whitefly resistance in the major cotton producing areas of Arizona confirmed the presence of an over 100 fold resistance to the mixture of Danitol® + Orthenem (fepropathrin + acephate). Strong evidence was found of cross-resistance affecting the other principle pyrethroid insecticides used to control whiteflies (Asana®, Capture® Karate®). Susceptibility to Ovasyn® varied widely in leaf -disk bioassays; lesser variation was observed in whitefly susceptibility to endosulfan. A provisional resistance management strategy (IRM) for Arizona whiteflies was formulated and evaluated in a 200 acre field trial in 1995. A key element of the strategy was diversifying as much as possible the insecticides used against whiteflies. Contrasts of this (rotation) strategy with a more conventional (less diverse) regime showed that rotation slowed but did not prevent resistance from developing. By seasons end both the IRM and conventional plots had very high and comparable levels of resistance to Danitol® + Ortliene®. This large field trial illustrated clearly the seriousness of the whitefly resistance problems faced in Arizona. It showed that whitefly populations cannot be managed effectively solely with the products currently registered for this purpose in Arizona. The large shift to lower susceptibility took place with as few as 3 insecticide treatments. In concert, our field art laboratory results indicated unequivocally that Arizona growers will be forced by resistance to greatly reduce reliance on pyrethroid insecticides in the future. This underscores the urgency for obtaining approval of novel new insecticides for whitefly control and for deploying new products within the framework of a resistance management strategy that limits their use.

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Kerns, David L. "Control of Early Woolly Whiteflies Infestations with Foliar Insecticides." College of Agriculture, University of Arizona (Tucson, AZ), 2003. http://hdl.handle.net/10150/198097.

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Five foliar insecticide treatments (Esteem, Provado, Applaud, Assail, and Danitol + Lorsban) were evaluated for their control of early woolly whitefly infestations in lemons. Esteem and Applaud are insect growth regulators that should have little impact on whitefly parasitoids. The impact of Provado and Assail on whitefly parasitoids is not certain, but at high rates may be detrimental, while Danitol + Lorsban will be especially harmful to parasitoids. The impact of these insecticides on woolly whitefly could not be fully determined in this trial due to the effectiveness of parasitoids, Eretmocerus comperei or E. dozieri (exact species not certain), on controlling the whiteflies in this test. However, other research (not reported here) has indicated that all of the insecticide treatments evaluated have good activity against woolly whitefly. Because parasitoids can be extremely effective in mitigating woolly whiteflies populations during the early phases of colonization, it is recommended that chemical control not be utilized until woolly whitefly colonies are common. However, previous experiences suggest that allowing woolly whitefly populations develop extremely high populations should be avoided.

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Ellsworth, Peter C. "Lygus Control Decision Aids for Arizona Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 2000. http://hdl.handle.net/10150/197516.

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Changes in insecticide use, available pest control technologies, and local crop ecology together with severely depressed cotton prices place a renewed premium on Lygus control decision aids for Arizona cotton. As part of an on-going program to develop research-based Lygus management recommendations, we investigated the impact of various timings of chemical controls on Lygus population dynamics, number of sprays, costs of control, and net revenue as well as cotton heights, trash, lint turnouts, and yields. Once there were at least 15 total Lygus per 100 sweeps, sprays were made according to the number of nymphs in the sample (0, 1, 4, 8 or 16 per 100 sweeps). Up to 7 sprays were required (15/0 regime) to meet the needs of the target threshold. Lygus adult densities were largely unresponsive to the treatment regimes or individual sprays made. Three generations of nymphs, however, were affected by the treatments with the ‘15/4’ regime harboring the fewest nymphs through July. This ‘moderate’ regime required 4 sprays and had the shortest plants, cleanest harvest, and highest lint turnouts. In addition, this regime out-yielded all other treatment regimes including the 6- (15/ 1) and 7- (15/0) spray regimes. Regression analyses of the data suggest that adult Lygus are less related to yield loss than nymphs and that large nymphs are best correlated with yield loss. Thus, spraying based on adults only would appear illadvised. Returns were highest ($747/A) for the 15/4 regime with over $100 more than the more protective regimes. Thus, there is no economic advantage in advancing chemical control when nymph levels are low. Maximum economic gain was achieved by waiting for the 4 nymphs per 100 level (with 15 total Lygus/100; 15/4) before spraying. However, waiting too long (beyond the 8 nymphs / 100 level; 15/8) resulted in significant reductions in yield and revenue. Our recommendations, therefore, are to apply insecticides against Lygus when there are at least 15 total Lygus, including at least 4 nymphs, per 100 sweeps. These recommendations are stable over a wide variety of economic conditions (market prices & insecticide costs). Continued work is necessary to verify these findings over a wider range of cotton developmental stages, varieties, and other environmental conditions.

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Umeda, Kai, and Chris Fredman. "Whitefly Control with Foliar Insecticides Following Imidacloprid in Cantaloupes." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/214742.

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Foliar insecticides for whiteflies (Bemisia sp., WF) were applied as a supplementary control measure at 6 weeks after treatment with imidacloprid (Admire®) at planting time of melons. Beauveria bassiana fungus spores (Mycotrol®), pyriproxyfen (S-71639, Valent), and azadirachtin (Align®) are non-conventional insecticides that could be safer on beneficial parasites and predators. The number of eggs and nymphs counted at all rating dates for all treatments were not significantly different from the foliarly untreated check. Mycotrol treated melons showed higher number of nymphs following the second application. The Align treatment tended to exhibit higher number of nymphs after two applications. The addition of an adjuvant did not appear to enhance pyriproxyfen efficacy.

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41

Rethwisch, Michael D., Jessica Grudovich, Steven Bennett, and Mark Reay. "Evaluation of Various Insecticides for Late Winter/Early Spring Insect Control, 2004." College of Agriculture, University of Arizona (Tucson, AZ), 2005. http://hdl.handle.net/10150/203838.

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Nine insecticides were applied on March 10, 2004, to alfalfa that had been water stressed prior to irrigation on March 6. These actions were thought to have resulted in treatments means with less distinct differences than usually noted for these treatments at 7-14 days post treatment. All pyrethroid treatments as well as Lorsban® and Steward® treatments resulted in significant reductions of alfalfa weevil larvae at four days post treatment. The Trilogy® treatment did not result in acceptable control of this pest. Significant increases in adult alfalfa weevils were noted at 10-14 days post treatment in pyrethroid treated alfalfa, perhaps due to increased production of certain plant volatiles in response to this class of insecticides. Low numbers of blue alfalfa aphids were noted in this study partially due to insecticide control as well as numerous beneficial insects. Fewest damsel bugs were noted from alfalfa treated with MustangMAXTM and Warrior® insecticides.

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42

Terry, Irene, and Ben Barstow. "Early Season Insect Control: Effects on Cotton Variety Yield and Fruiting." College of Agriculture, University of Arizona (Tucson, AZ), 1986. http://hdl.handle.net/10150/219766.

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The 1985 and 1986 Cotton Reports have the same publication and P-Series numbers.
Many cotton field trials were conducted in central Arizona to compare various early season pesticide treatments on several commercially available cultivars for plant growth responses and thrips control. Treated plots received either aldicarb (Temik), at planting or first square, or acephate (Orthene), one to three foliar applications during early squaring. Although results were quite variable, general trends included: most treatments did reduce thrips populations; fewer shed squares occurred in plots treated at first square; plants compensated for this square shed; treated plots may be earlier in boll production than untreated areas; and most tests showed no statistical differences in healthy square production or in yield.

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43

Terry, L. Irene. "Control of Early Season Insects." College of Agriculture, University of Arizona (Tucson, AZ), 1985. http://hdl.handle.net/10150/204085.

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44

Chu, C. C., and T. J. Henneberry. "Cultural Control and Pink Bollworm Populations." College of Agriculture, University of Arizona (Tucson, AZ), 1996. http://hdl.handle.net/10150/210914.

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A cotton management program in the Imperial Valley, CA was designed to reduce pink bollworm, Pectinophora gossypiella (Saunders), populations. The program established I March as the earliest planting date, 1 September for defoliant or plant growth regulator application and 1 November for cotton stalk destruction and plowdown. In-season gossyplure-baited pink bollworm male moth activity monitoring and immature green cotton boll inspections for larval infestation were encouraged as decision making aids to determine the need for additional control action. Male pink bollworm moth catches in gossyplure-baited Lingren and delta sticky traps were significantly reduced each year from 1990 to 1994 following the initiation of the management program in 1989. Fewer larvae per cotton boll occurred in the years from 1990 to 1992. Fiber quality of commercial cotton sampled was also improved from 1989 to 1994, as compared to the 1984 to 1988 average. Cotton production, in general, was reduced during 1989 to 1994 in areas surrounding Imperial Valley and may have contributed partially to reduced populations in Imperial Valley.

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45

Watson, Theo F. "Chemical Control of the Sweetpotato Whitefly in Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/209566.

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Both registered and experimental insecticides were evaluated for effectiveness against the sweetpotato whitefly in several field experiments at Yuma, Arizona. Best results were obtained with combinations of two insecticides, particularly a pyrethriod and an organophosphate, rather than with individual materials. Results of these experiments indicate that unusually heavy infestations can be currently controlled even though sustained use of these insecticides would probably lead quickly to the development of resistance.

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46

Watson, T. F., A. Telles, and M. Peña. "Chemical Control of the Sweetpotato Whitefly in Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209618.

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Various registered and experimental insecticides were evaluated for sweetpotato whitefly (Bemisia tabaci Gennadius) control in several field experiments at Yuma, Arizona in 1993. Best controls were obtained with insecticide mixtures, particularly a pyrethroid and an organophosphate, rather than with individual materials. Results of these experiments indicate that severe population densities can be controlled using insecticide combinations, even though sustained use of these insecticides would probably lead quickly to the development of resistance.

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47

Watson, T. F., M. A. Tellez, and M. Peña. "Chemical Control of the Sweetpotato Whitefly in Cotton." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/210295.

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Various registered and experimental insecticides were evaluated for sweetpotato whitefly (Bemisia tabaci Gennadius) control in several field experiments at Yuma, Arizona in 1994. Best controls were obtained with insecticide mixtures, particularly a pyrethroid and an organophosphate, rather than with individual materials. Results of these experiments indicate that severe population densities can be controlled using insecticide combinations, even though sustained use of these insecticides would probably lead quickly to the development of resistance.

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Ellsworth, Peter C., R. Gibson, D. Howell, S. Husman, S. Stedman, and B. Tickes. "Lygus Chemical Control: Are Combinations Sprays Worth It?" College of Agriculture, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/210368.

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We need efficient sampling methods, appropriate thresholds based on a well -defined Lygus density yield relationship, and knowledge of the most effective chemical controls available. Insecticides were evaluated for control of Lygus at 5 'at risk' grower locations, as well as at 4 other experimental sites. Application methods were different at each site according to grower practice or experimental protocol (5-20 GPA; by ground, air, or electrostatically-assisted ground sprayers). Evaluations were made based on the number of Lygus per 100 sweeps. Orthene®, Vydate® or to a lesser degree, Monitor® used alone and at high rates appeared to perform adequately at all sites. Both rates of Regent™, a new chemistry under development by Rhône- Poulenc, provided excellent levels of control comparable to Orthene in a high density test. In this same test, none of the experimental and registered pyrethmids provided adequate control when used alone. Thiodan®, when mixed with Mustang®, provided some level of control. Over all tests measured for yield, a positive net return was possible with no more than 2 sprays of solo materials which yielded between 0.3 and 0.5 bales/A more than untreated comparisons or between $51-130/A net return. Also, at one site where yields were in excess of 4.2 bales/A, optimum planting and fruit-set prior to heavy Lygus pressures and monsoon-associated heat stress was an important cultural tactic for avoiding losses to Lygus - the check yielded over 3.7 bales /A! As seen at grower sites and confirmed in experimental studies, solo compounds, at appropriate rates, performed as well or better than any combination tested. And, mixtures at this time do not appear to provide any additive, synergistic or economic benefits in the control of Lygus. Combinations, unless indicated by another pest problem (e.g., whiteflies), are not "worth it," and needlessly expose the grower to larger input costs, "empty" applications, and higher risks of resistance, pest resurgence, secondary pest outbreaks, and phytotoxic effects by insecticides.

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Lindegren, J. E., T. J. Henneberry, J. R. Raulston, Jech L. J. Forlow, and K. A. Valero. "Potential for Pink Bollworm Control with Entomopathogenic Nematodes." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/209640.

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The susceptibility of late instar pink bollworm (PBW), Pectinophora gosspiella (Saunders), larvae to two species of Steinemema was evaluated in small scale field tests in spring and summer of 1993. In the spring PBW mortality at 15 infective juveniles /cm² for S. carpocapsae and S. riobravis was 87 and 89 %, respectively. In midsummer, mortalities with S. riobravis were significantly greater than with S. carpocapsae at the four concentrations tested. A simple method was developed for small scale field testing and efficacy monitoring for PBW and other soil associated insects.

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Moore, Leon, and Theo F. Watson. "Trap Crop Effectiveness in Community Boll Weevil Control Programs." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/208357.

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Trap crops, along with delayed uniform planting and pinhead square treatments, greatly reduced spring populations of overwintered boll weevils, Anthonomus grandis Boheman, in a Laveen. Arizona community -wide 1PM program in 1987. Thirty four trap crops. planted fifteen days ahead of the regular crop. had as many as 39536 damaged plants/ha before insecticide treatments were initiated. Five insecticide applications at 3 day intervals beginning at square initiation were used to destroy weevils before the trap crops were plowed under at the time pinhead square treatments were initiated in regular planted fields. Damaged square infestations were 2 to II times lower throughout the season in 1987 compared to 1986 while average lint yields per ha increased from a low of 941 kg in 1985 to 1345 kg in 1986 and 1506 kg in 1987.

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Dissertations / Theses on the topic 'Cotton – Insect control and insecticides'

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