The fungus Verticillium lecanii was assessed for entomopathogenicity against nymphal Bemisia tabaci in an environmental chamber and in a greenhouse mist chamber on the host Euphorbia pulcherima. Proportional mortality of Bemisia nymphs due to fungal exposure were; in the environmental chamber 89-96%, and in the mist chamber 61-89%. Two fungal characteristics, hyphae growth and sporulation, were used as parameters for augmentation experiments. Response to particular honeydew constituents, glutamine, glutamic acid, serine and sucrose in concentrations ranging 500-40,000 ppm were measured. Hyphae growth, in comparison to water agar (1.26-1.52 mm/24 h), was inhibited by all substrates at all concentrations (0.82-1.47 mm/24 h). Sporulation was enhanced at higher concentrations, 17.0-117.0 (x10⁴) spores produced, in comparison with water agar, 10.2-15.5 (x10⁴) spores produced.

Female insects produce eggs that are nutrient-rich. For most Lepidoptera, protein is acquired during larval feeding. Insects use pre-ingestive, post-ingestive and developmental strategies to meet nutritional needs. In this dissertation I examine the importance of these strategies to females of two related lepidopteran species differing in their adult feeding. Adult Heliothis virescens (Family Noctuidae) ingests nectar. The sexes were not distinguished according to their selective feeding behavior, but females accumulated more protein and carbohydrate. When restricted to diets, females ate and accumulated more protein on high protein diets. There were no sexual differences on high carbohydrate diets. Results indicate that female H. virescens larvae accumulate protein by regulating both intake and post-ingestive processing on high protein foods. Adult Estigmene acrea (Family Arctiidae) do not feed. The sexes did not differ in their selective feeding behavior. When restricted to diets, female E. acrea increased ingestion of diets unbalanced in protein and carbohydrate leading to greater intake of both nutrients but only accumulated more protein. Lastly, E. acrea prolong juvenile development if too small at later stages effectively extending their period of ingestion and processing. As previously shown protein-derived growth in female H. virescens progressively increased as dietary protein levels increased. Storage protein, a component of protein-derived growth, was found to similarly increase but was more abundant in females across all pupal stages and diets. Pharate adults retained a portion of total storage protein with females retaining greater levels presumably toward egg provisioning. Growth of both H. virescens and E. acrea was highly clustered compared to ingestion values suggesting post-ingestive processing of nutrients to regulate growth. Males and females of both species efficiently utilized carbohydrate except at high ingestion. Females of both species utilized nitrogen more efficiently than did males at all ingestion levels, contributing to their greater protein accumulation. The manner of post-ingestive processing by these two species reflects differences in their larval diet. Clearly, my studies show that female caterpillars regulate both nutrient consumption and post-ingestive physiology to accumulate greater reserves.

<p> Molecular gut-content analysis is an established and increasingly important approach for tracking arthropod predation in the field. Previously, it is difficult to know what hemipteran generalist predators consume because there are no pieces of prey in their gut that could be identified following dissection. However, DNA of the prey item is present in a predator's gut for a certain amount of time. In order to relate the proportion of predator individuals found to contain pest DNA to the number of pests eaten over a given time period, it is necessary to determine how long pest DNA can be detected after predation has occurred. Studies were done to explore consumption of <i>Geocoris </i> and <i>Nabis</i> with green peach aphids and Colorado potato beetles.</p>

Abstract Not Available.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007. / Source: Dissertation Abstracts International, Volume: 68-07, Section: B, page: 4244. Adviser: Bettina M. Francis. Includes bibliographical references (leaves 57-63) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--Indiana University, Dept. of Biology, 2008. / Title from PDF t.p. (viewed on Jul 27, 2009). Source: Dissertation Abstracts International, Volume: 69-11, Section: B, page: 6633. Adviser: Curtis M. Lively.

Of the four most diverse insect orders, the Lepidoptera contain remarkably few predatory and/or parasitic taxa, and while species with carnivorous life histories have evolved independently numerous times in moths and butterflies, this has rarely led to diversification. As a rule, aphytophagous taxa seem prone to extinction. In this dissertation, I explore the ecological and evolutionary consequences of entomophagy in the butterfly family Lycaenidae using several approaches: natural history observation, phylogenetics, population genetics and stable isotope chemistry. A striking exception to the lack of radiation and persistence in aphytophagous lineages is the lycaenid subfamily Miletinae, which with 13 genera and 190 species is among the largest and most diverse groups of aphytophagous Lepidoptera. Most miletines eat Hemiptera, although some consume ant brood or are fed by trophallaxis from their host ant. I inferred the higher-level phylogeny of this group using data from one mitochondrial and six nuclear genes sampled from representatives of all genera and nearly half the described species. Biogeographic analyses indicate that Miletinae likely diverged from an African ancestor near the start of the Eocene, and four lineages dispersed between Africa and Asia. Phylogenetic constraint in prey selection is apparent at two levels: related miletine species are more likely to feed on related Hemiptera and are also more likely to associate with closely related ants species, either directly by eating the ants, or indirectly by eating hemipteran prey attended by those ants. I then examined the influence of diet on the population structure of lycaenid butterflies, and more specifically, I investigated whether particular feeding habits are correlated with traits that might make species vulnerable to extinction. To do this, I compared the phylogeography and population genetics of two endemic lycaenid species of roughly similar age from southern Africa: Chrysoritis chrysaor, whose caterpillars are strictly herbivorous, and Thestor protumnus, whose cuckoo-like caterpillars survive by soliciting regurgitations from their host ants. I sampled both species from populations throughout their entire known ranges, and found that in contrast to C. chrysaor, T. protumnus has exceedingly small effective population sizes and individuals disperse poorly. With its aphytophagous life history, T. protumnus exhibits a high degree of host dependence and specialization. Although these results are correlative and based on only a single comparison, it seems likely that small population sizes and extreme ecological specialization make populations of T. protumnus more susceptible to disturbance and prone to extinction. Having focused in detail on the population biology of just one species, I then analysed the evolution of Thestor as a whole. This genus is exceptional because all of its 27 described species are thought to be entomophagous, and all are thought to be predators or parasites of a single species of ant, Anoplolepis custodiens. Using representatives sampled from all known species and populations of Thestor as well as 15 outgroup species, I inferred the phylogeny of the genus in two ways: first by using characters from mitochondrial and nuclear genes, and second by analyzing genome-wide SNPs generated for each species using double digest RADseq. I also sequenced the ants associated with each of these taxa using ddRADseq. This investigtion showed that all 24 of the species in the Western Cape utilize Anoplolepis custodiens, while T. protumnusand T. dryburghi (the two species that are found in the north-western part of South Africa) use a closely related, but different species of Anoplolepis, and T. basutus (the species found in the eastern part of South Africa) utilizes yet a third species. Thus factors driving diversity in the genus Thestor may have initially involved ant associations and/or geographic isolation, but other forces are likely to be responsible for generating and maintaining the more recent diversity in the group. Flight time may have separated the “black” and “yellow” groups of Thestor: the black group fly predominantly in the summer months, while the yellow group fly predominantly in the spring. And while species spread across the genus fly in the spring and summer months, only members of the yellow group fly during the winter and fall months. Despite these broad scale differences, species in the genus Thestor show little evidence of niche partitioning, especially those in the Western Cape, and represent an extreme example of the coexistence of 24 species apparently utilizing a single food resource. While working on the previous three projects, I was surprised by the number of species of South African Lycaenidae with incomplete life histories despite decades of work by avid lepidopterists in the region. For example, in the genus Thestor, although all 27 species are assumed to be aphytophagous, partial life histories have been described for only four species. In part the paucity of data is due to the difficult terrain occupied by these butterflies, and the fact that those whose caterpillars associate with ants often spend significant portions of their lives hidden in ant nests in crevices of rock that are intractable for excavation and observation. To deepen our understanding of South African lycaenid life histories, I used nitrogen and carbon stable isotopic methods to survey a large number of species and their potential food sources. With these methods, I confirmed some known or suspected life histories and showed that in any one area, a species can have a highly variable diet. I also discovered that some of the nitrogen stable isotope values are much higher than expected for land animals, implying longer than average food chains and/or extreme environmental conditions. Together, these studies shed light on how carnivorous life histories affect the evolution of lycaenid butterflies, and help to explain why entomophagous lineages appear to be an evolutionary “dead end” in contrast to their herbivorous counterparts. / Biology, Organismic and Evolutionary

Calmodulin (CaM) is a major intracellular calcium receptor. There is abundant calmodulin (CaM) in the oocytes and eggs of B. germanica during vitellogenesis and early embryogenesis. The accumulation of CaM in oocytes may be for immediate use in the oocytes and/or in preparation for later stages of their development. Previous investigation from this laboratory suggested that maternal follicle cells are the most likely source of this CaM. Tissue culture labeling with $\sp{35}$S methionine showed a 13-fold higher rate of synthesis of CaM in the follicle cells than in oocyte preparations (Zhang & Kunkel, 1994). The high rate of biosynthesis of CaM in the follicle cells, and the absence of extracellular CaM in transit in the hemolymph suggested that CaM is made in the follicle cells and transferred to the oocytes. In order to obtain more information about the site of CaM synthesis I isolated total RNA from different tissues that could potentially contribute to the high amounts of follicular CaM and measured the amounts of CaM transcripts during development. I show that isolated whole follicles accumulate more transcripts for CaM than the fat body. The steady state levels of CaM transcripts increases 150 fold during the 4 day developmental period under study. This is in addition to a 32 fold increase in total follicle RNA during the period. Steady state levels of CaM transcripts in whole follicles also show a pattern of increase disproportionate to the increase in volume of the whole follicle. In comparison steady state levels of actin transcripts increase 35 fold during the same developmental period. At 96 hr post feeding, in a given amount of total RNA, follicle cell total RNA contains 3 times more CaM transcripts than whole follicle total RNA, and 70 times more CaM transcripts than the fat body tissue. The oocyte total RNA collected from material expelled from the whole follicle contains less than 10% of the amount of CaM transcripts available in the follicle cells. The fat body tissue preparation shows little developmental increase in steady state levels of CaM transcripts despite a 4 fold increase in total RNA. In my investigation into the control of the accumulation of this transcript I found that deprivation of JH, by head ligation, not only causes atresia of the follicles, but also reduces CaM transcript accumulation. Reconstituting JH titer by injection allows a selected population of follicles to develop to full size and also reinstates steady state CaM transcript levels above that of unligated controls. The results of my study makes the CaM gene a potentially important target for the study of JH action in follicle cells during oogenesis.

The intersegmental muscles (ISMs) of the tobacco hawkmoth, Manduca sexta, undergo two periods of developmentally programmed cell death. The first period occurs during the larval/pupal transition where half of the ISMs die and the remainder persist throughout pupal development until death upon eclosion of the adult. Both periods of ISM death employ much of the same molecular machinery even though the endocrine cues for the degeneration process is different for each period of muscle death. A gene that is dramatically increased in its expression during both periods of ISM death is polyubiquitin. This gene has been isolated and characterized in this research. Despite a large amount of allelic heterogeneity in the population, it has been determined that not only is this gene increased in response to developmental cues, but that its transcript is also increased in response to stress. Therefore, polyubiquitin is multifaceted in its regulation. Due to the diverse transcriptional regulation of this gene, it was determined to be a good candidate in which to develop a method to introduce promoter/reporter constructs into the ISMs of the hawkmoth. Even though this research does not conclusively demonstrate that reporter activity after transfection of the promoter/reporter constructs is due to the polyubiquitin promoter, the research does demonstrate that DNA mediated transfection of insect muscle tissue can be achieved.

Master of Science / Department of Grain Science and Industry / Subramanyam Bhadriraju / The development, relative retention, and oviposition of the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), on six different types of starches, wheat flour, and wheat flour plus yeast were investigated in the laboratory. The particle size of starch and flours were different; the mean size of 90% of particles for starches ranged from 15 μm for high amylose corn starch to 58 μm for potato, whereas that of the flour was ≤ 133 μm. Larval length, head capsule width, and weight gain of T. castaneum larvae were measured every 3 d on starches, flour, and flour plus 5% (by wt) yeast diet for 30 d at 28oC, 65% r.h., and 14:10 (L:D) photoperiod. Larvae reared on flour and flour plus yeast developed normally and showed better survival compared to those reared on starches. Larvae on the starches failed to develop beyond second, and rarely, third instars. Adults of T. castaneum did not show any preference to flour over starches in dual-choice tests in circular arenas. On average, T. castaneum laid less than 3 eggs/female over a 15-d period on starches compared to 97 and 109 eggs/female on flour and flour plus yeast diet, respectively. These studies suggest that starches are poor substrates for larval survival and development. Starches were as attractive as flour to adults; however, starches do not appear to be a suitable medium for egg-laying. Both aggregation pheromone and volatiles did not trigger oviposition behavior. Experiments by moving adults between wheat starch and wheat flour and vice versa showed that feeding on wheat flour was necessary for egg-laying, indicating the absence of essential nutrients in wheat starch. On wheat flour, feeding for 0.5 d was necessary to lay eggs. Females that were starved failed to lay eggs, reinforcing that the nutrional status of females and not males was essential for egg-laying. A minimum of 4% of wheat gluten (wheat protein) elicited egg-laying on starches, although 4-5 times fewer eggs were laid in starch gluten compared with wheat flour alone. Supplementing wheat starch with 1% cholesterol, in addition, to gluten, did not result in an increase in egg-laying by T. castaneum females. These findings suggest that starches may have potential in managing development and reproduction of T. castaneum—a pest that is common and severe in food-processing facilities. Furthermore, starches can be used as a suitable substrate for studying the nutritional ecology of T. castaneum.