Academic literature on the topic 'Mopane caterpillars'

ABSTRACTThe mopane worm, which is the caterpillar form of the Saturnid moth Imbrasia belina Westwood, is – like other edible insects and caterpillars – a vital source of protein in southern African countries. The worms live and graze on mopane trees, which have alternative uses. With increasing commercialization of the worm, its management, which was hitherto organized as a common property resource, has been degraded to almost open access. This paper uses a bioeconomic modelling approach to show that for some optimal allocation of the mopane forest stock, the restrictive harvest period policy advocated by community leaders may not lead to sustainable harvesting of the worm.

Abstract:Plant responses to herbivory vary depending on herbivory type, yet the comparative effects of defoliation (e.g. by insects) and pruning (e.g. by large mammals) on a single tree species are poorly documented. We investigated this in the Northern Province of South Africa by comparing the regrowth of Colophospermum mopane trees previously defoliated by caterpillars or pruned by elephants, the two main browsers of C. mopane foliage. Shoots were up to 160% and 125% longer after natural (elephant) and simulated pruning and leaves ~25% longer in regrowth after natural pruning (n = 13–15 trees per treatment). Shoot density and chemical defences in leaves (tannin:protein ratio and total polyphenolic concentration) were, however, no different from control trees. Simulated defoliation resulted in statistically insignificant changes to regrowth in terms of leaf and shoot size (both slightly decreased) and shoot density (slightly increased). Natural (caterpillar) defoliation, however, resulted in regrowth with significantly decreased shoot and leaf size (about 50% and 20% of control lengths, respectively), as well as decreased leaf chemical defence. Shoot and leaf length were longer on trees flushing for the first time after pruning and late-season defoliation had a greater negative impact than mid-season defoliation. Despite the differences in regrowth characteristics after pruning and defoliation, mopane plants showed no apparent trade-off in investment between tolerance and resistance after either herbivory type, as neither regrowth nor chemical defence occurred at the expense of the other.

Abstract:Responses of plants to herbivory are dependent on the type of damage and the ontogenetic stage of the plant. We compared the effects of stem pruning and defoliation on seedlings of Colophospermum mopane, an ecologically important tree species widely distributed in southern Africa. The growth of 160 greenhouse-grown juveniles were measured for 6-mo after germination and then 6-mo after treatments including 50% defoliation, 100% defoliation, 50% stem pruning and controls. Pruning resulted in 30% reductions in total leaf area, height and biomass. Partial defoliation resulted in 30% reductions in total leaf area and plant biomass. However, complete defoliation resulted in a 30% increase in biomass production, a doubling in leaf and lateral branch number, a 45% reduction in leaf size, and no change in total leaf area. Thus, completely defoliated seedlings showed greater performance than those that were only partially defoliated, indicating that C. mopane has become adapted to the chronic and severe defoliation inflicted by Imbrasia belina caterpillars. Comparison of our results with other studies indicates that C. mopane seedlings are less herbivory-tolerant than adults and that pruning has more negative effects than defoliation. Thus, seedling browsers may constrain recruitment in C. mopane, influencing its population dynamics and abundance.

Several insect species including termites, honey bees, American cockroach, grasshoppers, stink bugs, aquatic bugs, silkworms and mopane caterpillars are popularly consumed by indigenous and tribal communities in South America, sub-Saharan Africa, South-east Asia and the Pacific. Different life stages of the insects were found effective in therapeutic treatment against health disorders and life-threatening diseases. In entomophagy (process of insect eating), allergy, content of anti-nutrients, contamination of micro-organisms, chemicals and biochemical compounds, and parasitic infection are major constraints for wide adoption of entomophagy. An urgent attention of policymakers, people’s organizations and researchers is therefore needed. This review is focused on worldwide utilization of selected edible insects for therapeutic treatment wherever modern medical facilities are not readily available or indigenous people prefer traditional healers. Certain practical safety measures against anticipated health risk are also elaborated.

PurposeBetween 2006 and 2016, local communities in semi-arid Bobirwa sub-district in the Limpopo Basin part of Botswana had endured notable fluctuations in the delivery of critical ecosystem services. These changes have been coupled with adverse effects on local people’s livelihood options and well-being. However, a few such studies have focussed on the semi-arid to arid landscapes. This study therefore aims to provide recent knowledge and evidence of consequences of environmental change on semi-arid arid landscapes and communities.MethodologyTo examine these recent changes in key ecosystem services, the authors conducted six participatory mapping processes, eight key informant interviews and several rapid scoping appraisals in three study villages. The analyses were centred on changes in seasonal quantities, seasonality, condition of ecosystem service sites, distance to ecosystem service sites and total area providing these services. Drivers of change in the delivery of key ecosystem services and the associated adverse impacts on human well-being of these recent changes in bundles of ecosystem services delivered were also analyzed.FindingsResults show that adverse weather conditions, drought frequency, changes in land-use and/or land-cover together with unsustainable harvesting because of human influx on local resources have intensified in the past decade. There was circumstantial evidence that these drivers have resulted in adverse changes in quantities and seasonality of key ecosystem services such as edible Mopane caterpillars, natural pastures, wild fruits and cultivated crops. Similarly, distance to, condition and total area of sites providing some of the key ecosystem services such as firewood and natural pastures changed adversely. These adverse changes in the key ecosystem services were shown to increasingly threaten local livelihoods and human well-being.Research limitations/implicationsThis paper discusses the importance of engaging rural communities in semi-arid areas in a participatory manner and how such information can provide baseline information for further research. The paper also shows the utility of such processes and information toward integrating community values and knowledge into decisions regarding the management and utilization of local ecosystem services under a changing climate in data-poor regions such as the Bobirwa sub-district of Botswana. However, the extent to which this is possible depends on the decision makers’ willingness to support local initiatives through existing government structures and programmes.Originality/valueThis study shows the importance of engaging communities in a participatory manner to understand changes in local ecosystem services considering their unique connection with the natural environment. This is a critical step for decision makers toward integrating community values in the management and utilization of ecosystem services under a changing climate as well as informing more sustainable adaptive responses in semi-arid areas. However, the extent to which decision makers can integrate such findings to inform more sustainable responses to declining capacity of local ecosystems in semi-arid areas depends on how they value the bottom-up approach of gaining local knowledge as well as their willingness to support local initiatives through existing government structures and programmes.

Mophane worm is a name given to caterpillars hosted by the Mophane tree. The
 mophane worm is harvested as food supplement in most of the Southern African
 countries. For the past few years, there have been some reports indicating that the
 worm has disappeared in some parts of Botswana. Hence, the aim of this research
 study has been to investigate from an ethical perspective the impact of mophane
 worm depletion on the environment. A qualitative approach was used in this study
 and data was collected from the following target groups of people: villagers, headmen
 of the stated two villages and the Ministry of Environment, Wildlife and Tourism
 (MEWT) officers both at local and national level. The theoretical framework involved
 traditional theories (i.e., Value Theory and Utilitarianism) and environmental ethical
 theories (i.e., Social Ecology, Environmental and Intergenerational Justice).
 The research instruments employed were individual interview schedules, focus
 group discussions and observation. A fourfold model of analysis was used focusing
 on the biological, economical, social and political dimensions. From the findings
 of the study, it emerged that both natural and anthropogenic factors contributed to
 mophane worm depletion. The natural factors were drought and predation while the
 anthropogenic factors included massive usage of the host tree, destructive methods of
 harvesting and demand for more land for agricultural and residential purposes. It also
 emerged that mophane worm depletion had both negative and positive impacts on
 the environment. These included lack of money by the local people to buy their daily
 needs, lack of relish and poor livelihoods, loss of wildlife that fed on mophane worm
 and tension between government and local people over the regulation of the resource.
 Ethical evaluation revealed that the dominant value for the local people was utility
 value to the almost total lack of explicit awareness of intrinsic and inherent value,
 and that on utilitarian grounds, the overall evil that depletion of the mophane worm
 brought about outweighed its overall good effects. With regard to justice issues, the
 findings revealed that unjust social structures and injustices resulting from the unequal
 distribution of benefits and burdens as well as from the lack of adequate participation
 by the local communities in decision-making had a greater negative than positive
 impact. Finally, recommendations were made emphasising the utmost importance of
 government intervention to mitigate, if not, stop the depletion of the mophane worm.

Mopane (Colophospermum mopane) trees are browsed upon by two key species, namely mopane caterpillars (Imbrasia belina) and African elephants (Loxodonta africana), which each inflict a different type of damage while feeding, namely defoliation (leaf removal) and pruning (branch and/or stem breakage). Damage type can have a significant influence on plant responses, and these induced changes in morphological and chemical characteristics of regrowth can influence the subsequent feeding behaviour by each species. The objective of this study was therefore partly to investigate the differential effect of defoliation by mopane caterpillars and pruning by elephants on mopane trees, and then to investigate whether these two taxonomically different species interact through their shared food resource, by looking specifically at the effect of elephant utilisation of mopane on mopane caterpillar abundance. To determine the comparative effect of each browsing type, mopane trees were subjected to simulated mopane caterpillar or elephant utilisation treatments, at various frequencies and times within the year. Regrowth characteristics were then measured on treatment and control trees, as well as on naturally utilised and unutilised trees. Reproductive investment was also recorded on naturally utilised and unutilised trees. Additionally, the impact of mopane caterpillar defoliation and elephant pruning on plant stress was investigated by measuring the level of fluctuating asymmetry (FA) in leaves. Then, to determine whether there is an interaction between elephants and mopane caterpillars, mopane caterpillar egg mass abundance in areas of high elephant impact was compared to that in areas of low elephant impact. Firstly, however, in areas without elephant damage, those tree characteristics determining host tree preference by ovipositing mopane moths were identified. From this, an understanding of how elephant utilisation may influence mopane caterpillar abundance could therefore be gained. Defoliation and pruning had a significant different effect on mopane regrowth responses. Shoot and leaf length were significantly longer on pruned trees than control trees, for both naturally utilised and simulated elephant treatment trees, while there was no difference in shoot density. Defoliation, however, resulted in shorter shoots and leaves, particularly on naturally defoliated trees, which also had leaves of a higher nutritional value (tannin:protein ratio and total polyphenolic content) than control trees. A similar increase in leaf nutritional value was recorded in areas of high elephant impact in the Kruger National Park, but not after simulated or natural elephant damage in Venetia, where natural elephant utilization was less intense. Time since damage (i.e. first versus second flush) had a significant influence on regrowth after pruning, as shoot and leaf length were significantly longer on trees flushing for the first time, while within-season timing of damage was important for defoliation, as late-season defoliation had a greater negative impact than mid-season defoliation. Late-season defoliation also had a negative effect on leaf carriage into the dry season, while pruning appeared to aid leaf retention. Reproductive investment was found to be unaffected by mopane caterpillar defoliation or elephant pruning, as mean pod density and pod mass on utilised trees was no different to unutilised trees. Defoliation also had no influence on a plant’s likelihood of flowering that same season, with flowering being determined more by tree height. Unlike pod production, however, mean leaf density was significantly reduced in the regrowth of defoliated trees, presumably due to the use of stored resources for reproduction prior to the onset of regrowth. Neither simulated nor natural defoliation by mopane caterpillars and pruning by elephants was found to affect the level of leaf FA in mopane trees, even though the degree of damage inflicted on trees was considerably higher than in studies on other species where increases in FA were observed. Mopane therefore appears to be extremely tolerant of herbivory in comparison to other species. A positive relationship between leaf nutritional value (higher protein and lower tannin and polyphenolic content) and FA was detected, but only when trees from all study areas (i.e. a wide range of environmental conditions) were considered simultaneously. Environmental conditions, rather than herbivory, therefore appear to have a greater stressing affect on mopane. In the absence of heavy elephant utilisation of mopane trees, tree size, rather than shoot length, leaf length, leaf FA or leaf nutritional value, was found to have the greatest influence on oviposition behaviour of mopane moths. Ovipositing moths showed a preference for the tall riverine habitat over the shorter woodland and scrub mopane. This preference for large trees was, however, not evident at the individual tree level, as even though egg mass number per tree was positively related to tree height, large trees were not utilised more than expected according to the available canopy volume in each size class (resource availability). Heavy elephant utilisation of mopane had a negative impact on the density of tall trees within an area, due to branch and stem breakage while feeding. Unsurprisingly then, mopane caterpillar egg mass abundance was also significantly reduced in these areas, even though the nutritional value of leaves was higher than in non-elephant impacted areas. Elephants therefore appear to have a negative effect on mopane caterpillar abundance, primarily due to their negative impact on the density of tall mopane trees. This megaherbivore and invertebrate do therefore interact through their shared food resource, mopane trees.<br>Thesis (PhD (Zoology))--University of Pretoria, 2007.<br>Zoology and Entomology<br>unrestricted

Doctoral thesis submitted in fulfilment of the requirements for the Degree of Doctor of Philosophy to the Department of Development Studies, Faculty of Humanities at the University of the Witwatersrand, Johannesburg, South Africa, 2016.<br>Abstract This study examines the dynamics of power and the significance of local environmental knowledge in natural resource management in Zimbabwe’s communal areas. It uses a case study of Bulilima District, broken down into into 3 components (Wards) for manageability of the study, to analyse the power configurations and the role played by local environmental knowledge in influencing decision-making processes among actors in the district with regard to mopane worms (Imbrasis beilina is the scientific name while icimbi is the vernacular name) and mopane woodlands (Colophospermum mopane is the scientific name while iphane is the vernacular name). It examines the significance of local environmental knowledge, i.e. indigenous knowledge and knowledge that developed as a result of a combination of knowledges from different ethnic groups and modern science. The study further examines the dynamics of the gendered nature of mopane worms and woodlands tenure regimes by putting under the spotlight the spaces and places where men and women interact, use and exert control over mopane worms and woodlands. It places history at the centre of our understanding of contemporary power dynamics and helps us to appreciate the importance of how local environmental knowledge has changed over time. To this end, the study argues that some of the contemporary conflicts over resources have their roots in the colonial era when the colonial government appropriated land from the locals and introduced discourses and practices such as conservation. Furthermore, it argues and demonstrates that the state is a critical player in determining access, use and control of natural resources. Based on rich ethnographic data collected by means of critical observations, in-depth interviews, narratives, and archival data, as well as aided by a brief survey, the study concluded that natural resource governance is a complex phenomenon in developing states. Power and knowledge play significant roles in influencing access, use and control of mopane worms and woodlands. Furthermore, while some locals still possess indigenous knowledge, practices and belief systems related to natural resource management, these are now less significant in influencing decisions on natural resource management. Indeed, the interplay of knowledge and power in resource management sees scientific culture and outside knowledge taking precedence over local forms of knowledge in the management of natural resources in the district. Key words: power, local environmental knowledge, indigenous knowledge, ZANU PF, natural resource management, access, mopane worms and woodlands, Bulilima, Zimbabwe<br>GR2017