Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 255 for “"Biology, Entomology"”.
-
A P-glycoprotein-like mechanism in the nicotine-resistant insect, Manduca sexta.
The phenomenon of multi-drug resistance in tumor cells is mediated by the overexpression of a membrane protein called P-glycoprotein. Since its initial discovery in tumor cells, P-glycoprotein-like molecules have been found to transport a wide range of substrates in organisms from microorganisms to …
-
Effects of photoperiod, temperature, and diet on the development of the banded woollybear, Pyrrharctia (Isia) isabella (J. E. Smith) (Lepidoptera: Arctiidae).
The banded woollybear, Pyrrharctia isabella (J. E. Smith) was reared under laboratory conditions from egg to adult. Groups of individually reared larvae were kept at one of 8 photoperiods and in combination with one of 4 temperatures and were fed one of 6 artificial diets and fresh plantain. The …
-
The evolution of mating systems in black scavenger flies (Diptera: Sepsidae)
Black scavenger flies are characterized by sexual behaviours that are very unusual in insects. I have studied two of the most remarkable elements of their mating systems: the timing of copulations immediately after an oviposition bout (post-oviposition matings) and the males' escorting of …
-
Ecology and Evolution of Caste and Polymorphism in Pogonomyrmex Seed Harvester Ants
In conclusion, the many independent origins of caste in the social insects likely resulted from variation in the proximate factors that can yield phenotypic differences (e.g., larval diet, genetic variation, social regulation) and variation in the selective pressures favoring caste differentiation …
-
Aedes Albopictus in Peoria, an Invasion by an Exotic Mosquito Vector Into an Urban La Crosse Virus Endemic Area in Illinois
Although no direct evidence was found that Ae. albopictus is serving as a vector for La Crosse virus encephalitis, LAC virus continues to circulate in the sciurid amplifier host population and Ae. albopictus was shown to utilize sciurid bloodmeals. Continued surveillance is recommended to monitor …
-
Impact of Natural Mortality Factors on Populations of the European Corn Borer in Bt- and Non-Bt-Corn Fields in Illinois
In 1997 and 1998, field studies were conducted to evaluate the incidence of natural enemies of European corn borer in Bt cornfields. The findings were compared with assessments of the effects of natural enemies in non-Bt cornfields. In my study, corn type did not seem to affect the percentage of …
-
Species Composition and Genetic Structure of Grassland Plant Communities and Their Influence on Spiders and Herbivorous Insects
Chapter 5 presents a lesson on diversity for students. Students investigated how plant diversity influenced insect diversity in an urban environment. I believe educational outreach is a fundamental part of our jobs as scientists, so Chapter 5 provides an example of how we can use our research …
-
Induced Walking Behavior of Rhopalosiphum Padi L. (Homoptera: Aphididae)
Movement of apterous adults and fourth instar nymphs was monitored following different perturbations and combination of perturbations. Apterous aphids, caged overnight on oat plants in a 25-plant infestation focus in the center of each 900-plant plot, were subjected to a given perturbation or …
-
Chemically-Mediated Mate Location and Recognition in Longhorned Beetles (Coleoptera: Cerambycidae)
Larvae of many cerambycid species require woody host plants that are stressed or weakened in some way. Such hosts represent an ephemeral and unpredictable resource, with prime subcortical tissues being rapidly degraded by a variety of wood-feeding insects. Thus, the first larvae to colonize a host …
-
Chemoreceptors From the Hawk Moth Manduca Sexta L
In this study I cloned and characterized four M. sexta chemoreceptors. Differential screening of a male antennal cDNA library before the publication of the Drosophila melanogaster genome yielded one G coupled-protein receptor that had no matches in Genbank databases and the results of RT-PCR and …
-
Systematics and Evolution of the Basal Lineages of Therevidae (Insecta: Diptera)
The objective of this study was to resolve the relationships among the basal lineages of the family Therevidae (Insecta: Diptera) and to test the monophyly of the family and the two basal subfamilies. A chapter on the morphological features of Phycinae and Xestomyzinae was produced to unify the …
-
Chemical Ecology of Clytini (Coleoptera: Cerambycidae)
In chapter six, I characterize the contact sex pheromone of N. a. acuminatus. Males recognize female conspecifics only after contacting them with their antennae. I characterize the behavior and demonstrate that three methylalkanes present in the wax layer of females are sufficient to elicit a …
-
Ecology and Management of Riceland Mosquitoes in Africa With Special Reference to Culex Quinquefasciatus
The diverse mosquito species occurring in African rice agro-ecosystems have been scarcely studied despite the strong link between irrigated rice cultivation and mosquito-borne disease. Studies were conducted to determine the ecology of rice-land mosquitoes in Mwea rice agro-ecosystem, Kenya. In the …
-
Systematic Studies on the Leafhopper Subfamily Cicadellinae (Hemiptera: Cicadellidae)
Cicadellinae includes approximately 340 genera and over 2,000 species distributed worldwide, with member commonly referred to as sharpshooters. Sharpshooters are specialists on xylem sap, one of the nutritionally poorest diets, along with related cicadas and spittlebugs. Statistical analyses using …
-
The Opsins and Nuclear Receptors of the Honey Bee
The studies presented here illustrate the value of the recently sequenced honey bee genuine for the expansion of our knowledge of insect evolution and physiology. In the first study, a novel lineage of insect opsins is described based on the identification of a novel opsin gene, pteropsin, in the …
-
Bumble Bees (Apidae: Bombus) Through the Ages: Historical Biogeography and the Evolution of Color Diversity
In the final chapter, I add the rare obligate social parasite Bombus inexspectatus to the phylogeny to assess the evolution of social parasitism. B. inexspectatus is not the sister taxon to its host B. ruderarius, but a close relative, and therefore adheres to the loose version of Emery's rule.
-
Molecular Phylogeny of Stingless Bees: Insights Into Divergence Times, Biogeography, and Nest Architecture Evolution (Hymenoptera: Apidae: Meliponini)
The dissertation is concluded with a biological catalog of the Indo-Malayan/Australasian stingless bees including 519 literature references, and deals with 129 proposed names for species-group taxa, of which 89 are considered currently valid. Information is summarized on organisms associated with …
-
Toxicogenomics of Apis Mellifera
Collectively, the studies reported in this dissertation demonstrate that honey bee P450s associated with detoxification are few in number, that these P450s appear to have evolved to respond specifically to natural compounds encountered in the hive environment, and that honey bees have a limited …
-
Gene Expression and Behaviors Relating to Rotation Resistance in the Western Corn Rootworm, Diabrotica Virgifera Virgifera (Coleoptera: Chrysomelidae)
Yearly rotation of corn with another crop interrupts the life cycle of the western corn rootworm beetle (Diabrotica virgifera virgifera, Coleoptera: Chrysomelidae), but behavioral resistance to crop rotation is a major problem. Resistant adult females exhibit reduced fidelity to corn due to …
-
Effects of Natural Enemies and Host Condition on Populations of Insect Pests of Trees
In the third chapter, I reviewed the primary and secondary literature on parasitoids of the wood-boring larvae of cerambycid beetles to examine the relationship between the feeding niche of beetles and the number and types of parasitoids that attack them. Significantly fewer species of parasitoids …
Page 1 of 13