Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references.

The incidence of parasitism by Bunodera mediovitellata in Trichoptera in Tin Can Creek was investigated. Larvae of Lepidostoma roafi had a low incidence of infection , while Psychoglypha alascensis larvae had a high incidence of infection. The encapsulation reactions of these Trichoptera larvae to internal Epon implants, and metacercariae of the parasite encysted within the silk glands, were examined in vivo to determine the details of the cellular encapsulation reactions of Trichoptera to foreign objects in both of these sites, and to determine which hemocytes are involved in the reaction. The hemocytes of larvae of P. alascensis were capable of encapsulating Epon implants within the hemocoele; the reaction took approximately twenty days longer than those of other insects that have been maintained at 20°C. The hemocytes of larvae of P. alascensis are also capable of encapsulating the metacercariae of their natural parasite B. mediovitellata in the silk glands despite the normal absence of hemocytes from the silk gland lumen. The hemocyte capsules around both the non-living and living objects was typical of the 'ordinary encapsulation reaction' described by Salt (1970). The capsule consisted of an inner layer of flattened cells which were densely packed and an outer layer of cells which were not flattened to the same extent as those of the inner layer. The hemocytes which took part in both capsules around implants and capsules around parasites were flattened elongated hemocytes which probably correspond to plasmatocytes or granulocytes. However, the production of a Summary Fate Map of free circulating hemocytes demonstrated that hemocyte types are stages in the development of a number of lines of hemocyte types. It appears that the hemocytes taking part in the encapsulation reactions belong to two of these lines of hemocyte types. / Science, Faculty of / Zoology, Department of / Graduate

Call number: LD2668 .T4 1965 L332 / Master of Science

Thesis (PhD. (Zoology)) --University of Limpopo, 2013 / Edible insects have been used as a nutritious food source by mankind for millennia, but in the modern era their use in more industrialised and western countries has dwindled. In the face of concern over the global food security crisis, scientists are urging investigation into edible insects as an alternate food. This study contributes to this global initiative by investigating entomophagy in the Blouberg area of the Limpopo Province, South Africa. The research develops a database of Blouberg edible insects, documents the importance of entomophagy to the people of Blouberg and for the wider community, and investigates aspects of the biology, ecology, socio-economics and nutritional value of a key species harvested in the area. Semi-structured questionnaires were carried out between 2007 and 2008 amongst households in the vicinity of Blouberg Mountain. Nearly 91% of the households in the Blouberg area consume insects. The most important reasons cited for consuming insects are that they are a traditional food, that they taste good and that they are a free food resource. Twenty eight species of edible insects were identified to at least genus level. Education was more important than income in influencing whether or not insects were consumed in a household. Households with lower education scores were more likely to consume insects than those with mid-level education scores. However, those with low income scores consumed a greater quantity of insects than those with higher scores. Similarly, those with low education scores consumed more insects than those with higher education scores. Pasture land was the area most preferred for collecting insects, with crop lands second in importance. Natural vegetation was not a preferred collecting habitat. Most households (78.57%) believe there has been a decline in edible insect consumption in recent years. According to the Blouberg insect collectors, edible insects are also on the decline in Blouberg and most households are unhappy about this. The lepidopteran, Hemijana variegata (bophetha), which was targeted for more in depth research, was found to be univoltine in the field, with caterpillars emerging in early November. The caterpillars feed predominantly on Canthium armatum and to a lesser extent on Pyrostria hystrix. They take four weeks to develop, burrowing into the soil to overwinter as pupae to emerge as adults in late spring. The development of the moth is profoundly influenced by temperature at all life stages and ceased below 17ºC and above 35ºC. Temperatures between 23ºC and 29ºC were most favourable for growth. The food value of the bophetha caterpillars was found to be high. The protein value of traditionally prepared caterpillars is 45.5%, with carbohydrates at 11.86 mg/100 g and fat at 19.75%. The caterpillars are not as rich in vitamins as fruit or vegetables, but compare favourably with beef. Traditionally prepared bophetha were found to be contaminated by two bacteria and one fungus, none of which are dangerously pathogenic to humans. Bophetha are traded between Blouberg villages at costs equivalent to other edible insects in South Africa (R10.19 per cup). Almost one third of Blouberg inhabitants sell bophetha, with this percentage decreasing to about 10% in poor seasons. Households collect between 3 and 3.5 litres of bophetha per season. Blouberg households are of the opinion that knowledge about edible insects is important enough that it should be included in formal education as a way of ensuring that the younger generation assimilates aspects of this knowledge despite cultural changes. The results of the study emphasise the importance of natural resource use with respect to edible insects in a marginalised community.

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Thesis (Ph.D.)--Tufts University, 2000. / Adviser: Sara M. Lewis. Submitted to the Dept. of Biology. Includes bibliographical references (leaves 82-90). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (Ph.D.)--Tufts University, 2005. / Adviser: Sara M. Lewis. Submitted to the Dept. of Biology. Includes bibliographical references. Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Thesis (Ph.D. (Zoology & Entomology)) - Rhodes University, 2008.