Thesis (M.Sc.(Entomology ))--University of Pretoria, 2002. / Includes abstract in English. Includes bibliographical references.

Thesis (Ph. D.)--Swedish University of Agricultural Sciences, 2001. / Thesis statement in Swedish and English abstract inserted. Includes bibliographical references.

The biology and ecology of the endocoprid dung beetles of the Aethiopian zoogeographic region has been studied in the field and laboratory. Work has centred mainly on Oniticellus planatus and O. formoaus although infomation has also been supplied on O. egregius, O. pictus and Tragiscus dimidiatus. The taxonomy of Onticellus (s.str.) and Tragiscus has been discussed with the recommendation that O. planattus and O. pseudaplanatus be synonymised. It has been suggested that endocoprid distribution is chiefly controlled by temperature, rainfall and the density of suitable large dung masses. On the basis of distribution it has been suggested that the taxonomic status of the subspecies of O. pictus should be reviewed. Endocoprids (genus Oniticellus (s.str.) are found throughout the warmer regions of Africa and Asia. Tragiscus is found only in Africa. Methods are described for monitoring endocoprids in the field, for distinguishing freshly emerged from older specimens, and for breeding endocoprids under laboratory conditions. It has been shown that endocoprids breed within or just beneath large dung masses unlike most other members of the Scarabaeinae which actively bury dung and construct the their broods at depth in the soil. It has been shown that there is a restriction of breeding sites available to endocoprids due to the removal of dung by the Scarabaeinae beetles and the limited space available within dung pads. This has resulted in low endocoprid population numbers, a disadvantage, which has been countered by highly specialised but opportunistic breeding habits. The requirements of dung plasticity have limited the time available for breeding activity by most endocoprids (excluding O. egresius) so that both the reproductive system and the reproductive behaviour (cf. O. planatus) are geared to rapid egg and brood production. Large numbers of follicles are able to be produced over a short period. In the probable absence of feeding, this has possibly been allowed by the involvement of a well developed fat body. The broods are tended by the parent female during larval development and the follicles are gradually resorbed, probably to prevent starvation. Ovarian recovery is rapid once feeding recommences. Behavioural mechanisms have developed which boost the number of broods constructed and the rapidity with which they are produced. The duration of endocoprid colonisation and the timing of arrival at dung is shown to be related to the rate of pad desiccation which is chiefly controlled by temperature and degree of dung removal by other dung beetles. Precipitation may also play a part. Predation by vertebrates and other insects has been noted and a number of mechanisms are described which are probably protective. Two insect parasitoids of O. formosus larvae have been recorded. The potential use of endocoprids in the Australian dung and fly control project has been discussed and it is recommended that their introduction be considered of low priority. It is suggested that the endocoprids evolved from Euoniticellus type ancestors and that their behaviour complex nidification developed in response to harsh environmental factors, chiefly the danger of desiccation and competition for dung with other dung beetles. From a consideration of brood and brood chamber construction it is suggested that O. egresius is a relatively unspecialised endocoprid which may retain dry season aestivation and has not evolved much further than its probable Euoniticellus type ancestor. The broods are coated in clay and abandoned soon after construction. Greater specialisation is shown by O. planatus and O. formosus which exhibit brooding behaviour, increasing longevity, more specialised brood protection, increased potential fecundity and continuous activity throughout the year. O. formosus shows greater specialisation in brood production than O. planatus. Greatest specialisation is found in T. dimidiatus which exhibits a precise brooding period and low egg production. Brood construction is of a similar degree of specialisation to that of O. formosus. Activity is also continuous throughout the year. The comparative biology of the five southern African endocoprids is summarised in Table 35. Summary, p. 129-131.

Thesis (M.Sc.(Zoology)) -- University of Pretoria, 1999. / Includes bibliographical references.

Thesis (Ph.D.)(Entomology)--University of Pretoria, 2005. / Title from opening screen (viewed March 20, 2006). Includes summary. Includes bibliographical references.

Please read the abstract in the section 00front of this document / Dissertation (MSc (Entomology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

Please read the abstract in the section 00front of this document / Thesis (PhD (Entomology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

This dissertation was submitted to the Faculty of Science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Master of Science / Dung beetle feeding is still not a widely understood behaviour. Feeding on the waste of other animals creates a challenge of acquiring the necessary nutrients for growth, development and for survival. Because of their soft mouthparts, it has always been thought that adult dung beetles cannot chew the hard parts of dung but only select smaller particles to feed on. Dung beetle larvae on the other hand can chew harder components, but where they get the nutrients required for development has not yet been discovered. The aim of this study was to discover which dung particles adult dung beetles select when feeding, and when creating a nest for their offspring, and also how much they can alter the dung nutrient content in the process. Foregut and hindgut contents were dissected out of the dung beetle Scarabaeus goryi, and their contents compared with untreated dung from the cow and the excreta of adult beetles. Brood balls and maternal gifts of Euoniticellus intermedius were also dissected. Nitrogen and carbon content, the carbon to nitrogen ratio, and results of the carbon and nitrogen stable isotopes were compared between all samples. When feeding dung beetles selected particles which were bigger than 800 μm in diameter and had three times more nitrogen than raw dung, and used particles over 2000 μm in size in the maternal gift packed for their offspring. Nitrogen content in the selected dung was increased from 1.40 % to 5.14% by adult dung beetle feeding and up to 2.62% in dung selected for the larvae to feed on. The carbon to nitrogen ratio also decreased when feeding adults and in the brood balls made for the larvae to feed on. Both carbon and nitrogen were absorbed from ingested dung during digestion. The heavier nitrogen isotope was selected for when feeding. The heavier nitrogen isotopes and the lighter carbon isotope were selected for during absorption. Dung beetles increase the nitrogen content of the dung on which they feed by careful selection of particles of a certain size and nitrogen content, which is probably the limiting nutrient when feeding and nesting. The increase in the nitrogen content is not only from the change in particle size but also in selection of particles with higher nitrogen content. / MT2018

The number of people on our planet is projected to rise to between 9.4 and 10 billion by 2050. Some estimates suggest that current levels of food production will need to double to feed this population. Increasing the intensity of food production on existing agricultural land will be a crucial element in meeting this goal, but practices associated with intensive management can cause biodiversity declines and erode the ecosystem functions that underpin production. My work explores agricultural intensification within the context of pasture-based cattle production. I focus on a variety of ecosystem functions supported by dung beetles (Coleoptera: Scarabaeoidea) and other dung-associated invertebrates. I investigate how variations in diversity, and chemical perturbations of veterinary anthelmintics affect the delivery of multiple ecosystem functions. I show that maintaining species-rich dung beetle assemblages has inconsistent benefits in providing multiple ecosystem functions. While dung beetles play an important role in supporting functioning in the short term, my work also reveals that their contributions may be less evident when considered over longer periods. Chemical perturbations caused by anthelmintic residues represent a significant threat to some invertebrate groups, but my experiments show that exposure does not always translate into an immediate reduction in ecosystem functioning. While use of anthelmintic products with relatively low toxicological risk did not cause obvious reductions in function, my work shows exposure can have significant consequences for the conservation of sensitive species. Overall, my work highlights the need for multigenerational studies, mathematical modelling, and careful consideration of sublethal effects to assess fully the risks of anthelmintic residues in the pasture environment. Furthermore, the emphasis on dung beetles (rather than other dung-associated invertebrates) in the existing literature neglects potentially important functional benefits provided by other taxa, such as earthworms. As the global human population continues to expand, it is important that we find sustainable ways to produce food while simultaneously conserving biodiversity. As loss of biodiversity in agricultural ecosystems does not always have functional consequences, it is important that wider justifications for conservation remain integrated into agricultural policy and practice.

As bacteria are becoming resistant to conventional antibiotics, researchers are looking for new ways to combat microbial infection. We have begun to adopt genetic and functional genomic approaches to define the molecular determinants of pathogen resistance in the dung beetle, Euoniticellus intermedius. This dung beetle survives microbe-rich environments such as dung. This ability makes it a potential model for the study of infectious agents and ecological damage. To date, E. intermedius has not been studied at the molecular level. In this study, a range of complimentary analytical techniques were used to characterize the E. intermedius embryonic cell line established in our laboratory. These techniques characterize morphology, growth characteristics, karyotype, isoenzyme patterns and embryonic development. Complete characterization of the E. intermedius cell line is essential for the cell banks and for the regulatory requirements in biopharmaceutical production. This study followed gene sequences and their comparisons for both adult and cell line to confirm that the E. intermedius (EISA08) cell line is originated from the embryonic E. intermedius dung beetle. cDNA was synthesized from mRNA isolated from E. intermedius adult beetles and cell line (EISA08) was sequenced using GS (FLX) technology by a commercial facility, Inqaba Biotechnical Industries (Pty) Ltd, South Africa. In addition to characterization of the cell line, two genes, namely hopscotch and ribosomal protein S9 (RpS9), were selected from the Flylab genome data base. The E. intermedius database is a web-based system for the genome and transcriptome of the dung beetle to evaluate the immune system of the dung beetle (http://Flylab.wits.ac.za/). hopscotch was selected because it is believed to be involved in the JAK-STAT signalling pathway for anti-viral response, embryonic development and cell growth. Rsp9 was chosen as a loading control because it is expected to be a housekeeping gene. The conserved molecular signalling pathway JAK-STAT is used by E. intermedius (as in other insects and humans) for immune defence and early embryonic development. The project followed hopscotch and Rsp9 gene expression in all the E. intermedius life cycle developing stages; adult, pupae, larvae, embryo, and cell line cell growth, life cycle developing stages and embryonic development has was monitored. E. intermedius embryonic development is described as short germ-band. E. intermedius embryogenesis is regarded as basal and is observed in most arthropods. The study revealed that E. intermedius hopscotch is over expressed in the early developing stages, embryo, larvae, and pupae and in the newly established cell line EISA08. The results from this study lead to the suggestion that E. intermedius JAK-STAT pathway is activated early and has an important role in embryonic development, cell proliferation and immune defence. Studies of E. intermedius could provide more insight into the properties and evolution of innate immunity and embryonic development.