A taxonomic revision and phylogenetic reconstruction of the Thraulus group genera and their species was carried out based upon the examination of external morphological characters. Nine new taxa are described (four genera and five species) and four species previously assigned to Thraulus have been reassigned to these new genera. Seven species remain assigned to Thraulus. Simothraulus remains monotypic. The five species of Neotropical Thraulus have been reassigned to other Central and South American genera, making the distribution of the Thraulus group genera exclusive to the Eastern Hemisphere. Keys to genera and species for known imagos and nymphs are provided, and diagnostic characters are illustrated. / Cladistic methodology was used to reconstruct the probable phylogeny of the Thraulus group genera and their species. The South American Ulmeritus group was identified as the sister group of the Thraulus group genera, as both share the following derived character states: the fork of vein MA of the fore wings is symmetrical, an oblique cross vein occurs in the fore wings between veins R(,4+5) and MA(,1) just apical to the fork of vein MA, and the abdominal gills are fimbriate. The Thraulus group genera share the following derived character states: vein Sc of the hind wings ends at the base of the costal projection, the apical margin of the lingua of the hypopharynx is bare, and nymphs have posterolateral spines on abdominal terga 6-9, 7-9, or 8-9. Species unknown in the nymphal stage could not be confidently placed in the phylogeny. Two parallelisms have occurred among the species of Thraulus: the loss of the row of setae on the lateral margin of the mandibles at the base of the incisors and the reduction in both lamellae of abdominal gill 1. / Source: Dissertation Abstracts International, Volume: 46-10, Section: B, page: 3326. / Thesis (Ph.D.)--The Florida State University, 1985.

The taxonomy, zoogeography and phylogeny of the genus Dicrotendipes Kieffer, 1913 (Insecta: Diptera: Chironomidae) are reviewed on a world-wide basis. Sixty-eight species names are considered valid; the type-species for the genus is Chironomus septemmaculatus Becker, 1908. / The taxonomy of 14 species recognized from the Afrotropical region is reviewed. The previously unknown larvae and pupae of D. fusconotatus (Kieffer), D. kribiicola (Kieffer), D. septemmaculatus and D. sudanicus (Freeman), and the pupa of D. cordatus Kieffer are described. / Fifteen species are recorded from the Neotropical region. The adult males of 9 new species are described; adult females are described for 2 new species; and pupae are described for 2 new species. A key is provided to identify Neotropical adult males. / A total of 17 species are recognized from the combined Oriental, Australian and Oceanian regions. Three species previously considered to be Dicrotendipes are removed: Ch. blandellus Kieffer, D. paxillus Guha, Chaudhuri & Nandi, and D. socionotus Guha, Chaudhuri & Nandi. Seven new species are described from the combined regions. In addition, the males and females are redescribed, and pupae and larvae described, for: D. candidibasis (Edwards), D. conjunctus (Walker) and D. pelochloris (Kieffer); adult males are redescribed for D. bilobatus Kieffer and D. tenuiforceps (Kieffer). The pupa and larva of D. flexus (Johannsen) are redescribed. Keys are provided for adult males, pupae and larvae. / Distributions of selected species are discussed and distribution maps are provided. The phylogney of Dicrotendipes species known in all 3 life stages is analyzed utilizing a Hennigian cladistic analysis and a computer program, PAUP. Results of the analyses are similar, and indicate that 3 major lineages occur within the genus, with at least 9 species groups. / Source: Dissertation Abstracts International, Volume: 48-03, Section: B, page: 0638. / Thesis (Ph.D.)--The Florida State University, 1987.

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

Complex signaling, while common throughout the animal kingdom, is poorly understood and generally understudied. This dissertation provides a framework from which one can approach studies of complex signal function. The semantics involved in studies of signal evolution and complex signaling are discussed and complex signaling is broken down into two categories: multiple signals and multimodal signals. While single signals ultimately reflect the pressures of both tactical and strategic design, so must complex signals. I explore hypotheses relating to the function of complex signaling in terms of both tactical and strategic design pressures and then explore hypotheses allowing for the possibility of inter-signal interactions. Predictions of some tactical design hypotheses of complex signaling suggest that multimodal signals can act independently, as back-ups to each other in the presence of environmental noise, or they can interact in a variety of ways. I tested the tactical back-up hypothesis, among others, using the bimodal signaling wolf spider Schizocosa uetzi. Results suggest that the signals are not independent and that there is an inter-signal interaction in which the vibratory signal redirects and focuses a female's attention to the visual signal. A comparative approach explored the tactical and strategic design components of multimodal signaling across three species of Schizocosa, one unimodal signaling species (S. avida, vibration only) and two bimodally signaling species (S. uetzi and S. stridulans). Signal non-independence was found for both bimodally signaling species but the pattern of inter-signal interaction differed between the species. Inter-population interactions between divergent populations that possess independent, derived traits can also be affected by inter-signal interactions. Results from an empirical study using two divergent populations of the jumping spider Habronattus pugillis in inter-populational reciprocal crosses were compared to predictions of different models of sexual selection. Our results show a xenophilic mating preference with one population of females mating more frequently with foreign males than local males, while the second population of females showed no such difference. While this pattern is inconsistent with Fisherian selection and does not completely fit the predictions of pure sensory exploitation, it is completely consistent with one pattern predicted from a process of antagonistic coevolution.

The congeneric wasps, Encarsia formosa and E. pergandiella (Hymenoptera: Aphelinidae) are solitary endoparasitoids with an overlapping host range. Despite their similarities these wasps produce eggs that differ markedly in size. This dissertation details research conducted to determine differences in the egg provisioning strategies of these two wasp species and to understand how these differences correlate with differences in their early development. The use of the yolk protein, vitellogenin, was examined in the two wasps. A vitellogenin gene was isolated from E. formosa and the mature gene product observed in ovary extracts. Evidence for the use of vitellogenin was not found in an analysis of ovary extracts from E. pergandiella and a gene for vitellogenin was not detected in the genome of this wasp. Embryonic development times for the two parasitoids were studied in hosts of different ages. The embryonic development time of E. formosa is significantly shorter than that of E. pergandiella regardless of the host stage parasitized. This suggests that the rate of embryonic development of E. pergandiella is much more closely linked to that of the host than the development rate of E. formosa. The quantity and composition of amino acids in the eggs of the two wasps was followed over the course of embryonic development. The quantity of amino acid in the eggs of E. formosa does not increase during embryonic development while the eggs of E. pergandiella absorb more than 30 times the quantity of amino acids from the host hemolymph during embryonic development than is present in the eggs at the time oviposition. Only E. pergandiella appeared capable of absorbing and utilizing [¹⁴C]-labeled lysine in an in vitro system. The capacity of E. pergandiella eggs to absorb host nutrients is correlated with the development of a multinucleate extraembryonic membrane that grows to completely encompass the embryo at a very early stage of development. Evidence was found for pinocytosis of material by the embryo from the space bounded by the extraembryonic membrane. A similarly developed extraembryonic membrane was not observed in the eggs of E. formosa .

Nutrient storage is an important, but understudied life history trait. One approach to characterizing the role of nutrient storage in insect life histories begins with determining the rules that organisms use to allocate nutrients to storage in comparison to other life history traits. My dissertation research focuses on understanding rules of allocation to nutrient storage in two types of insects that differ in their life histories, grasshoppers and ants. First, I showed that the grasshopper, Schistocerca americana , differs from other known grasshoppers by having only a single dominant storage hexamerin that occurs in both larvae and adults. Second, I showed that allocation between somatic growth and lipid storage at the last larval-adult molt in females of the grasshopper, Schistocerca americana, was plastic in response to larval resource availability. On the best growth diet, individuals were larger and contained proportionally greater lipid stores than individuals on the lowest nutrient content diet. Prioritization of nutrient allocation to somatic growth over lipid storage on poor diets in Schistocerca americana females suggests that larvally derived lipid stores have some role in adult fitness, but that body size is more important. Third, I showed that two closely related members of the Camponotus festinatus species complex of desert carpenter ants differ in their life histories with respect to lipid storage. Dark-form workers and soldiers stored significantly more lipid per unit lean mass than light-form workers or soldiers, but light-form colonies involved a slightly larger proportion of soldiers in storing lipid. Fourth, we showed that there was a relationship between storage protein content of queens and founding strategies in five species of Harvester Ants in the genus Pogonomyrmex. Independent claustral-founding species contained the greatest protein stores, followed by independent facultative-foraging queens. Independent obligate-foraging queens, and queens of a dependent social parasite contained almost no protein stores. Last, we showed that arboreal and terrestrial ants differed in both seasonal foraging activity and nutritional preferences in a lowland neo-tropical forest. Differences in foraging and nutritional preferences likely reflect fundamental differences in nutrient availability in the two habitats.

Evolution of new adaptations in response to novel environmental selection pressures is often associated with negative pleiotropic costs. Fitness costs may be ameliorated by further evolutionary processes if selection pressure is maintained. Modifier mutations that ameliorate the fitness costs of resistance mutation may arise. Alternatively, resistance mutations that incur lower fitness costs at the same locus or other loci will replace the resistance mutations with high fitness costs. Taylor and Feyereisen (1996) proposed a hypothesis of genetic "succession" for such a mechanism in the evolution of resistance to toxins. Numerous disruptive mutations in the target of a toxin may confer resistance, but with the likelihood of high fitness costs at an early stage in the evolution of resistance. Rare specific mutation(s) with less fitness costs will replace the early resistance allele(s) at a later stage and form a genetic succession. The genetic succession hypothesis is examined in this dissertation. Theory and modeling predicts that genetic succession is likely a process involved in resistance evolution against stimulatory toxins. Thus, numerous disruptive mutations on the target site will confer resistance with high fitness costs initially, but later will be replaced by rare specific mutation(s) with lower fitness costs. Genetic succession is also investigated in the case of sodium channel mutations for pyrethroid resistance in Heliothis virescens. Three distinct resistance mutations in or near the H. virescens sodium channel gene hscp have been determined by sequence comparisons; Val 421 to Met (V421M), Leu1029 to His (L1029H), and the third factor linked to Hpy5 allele that involves neither of the mutations V421M or L1029H. Frequency changes in these mutations during the time of sampling (1990 to 1997) suggest a successional replacement of both V421M and an unknown Hpy5-linked mutation by L1029H in Louisiana H. virescens populations. Further information on relative fitness costs of the mutations is necessary before we can conclude with confidence that the apparent replacement of the V421M and Hpy5 linked resistance by L1029H H. virescens represents a genuine successional event.

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 ovipositing females. In a study of the patterns of sperm precedence in one sepsid species, I found that the sepsids' peculiar timing of matings is not associated with unusual patterns of sperm precedence: sepsid males displace rival sperm and achieve a large last male advantage, which is the most common outcome of sperm competition in insects. I discuss the potential significance of sperm transfer mechanisms for the sepsids' timing of matings, and I consider factors that may favour the maintenance of post-oviposition matings in sepsid populations. In a survey of sepsid mating patterns, I found that post-oviposition matings are typical of many black scavenger flies and that mating systems characterized by the absence of copulations with gravid females may have arisen early in the family's evolutionary history. In several black scavenger flies, ovipositing females are commonly accompanied by an escorting male, and in all but one of the species I have studied, escorting is pre-copulatory. In several species, I found pronounced geographic variation in the expression of this trait. I argue that sepsids share certain characteristics which may have facilitated multiple independent origins of escorting behaviour. In order to investigate the adaptive significance of escorting, I have conducted a comparative study of patterns of sexual size dimorphism and sex ratios at oviposition sites in conspecific populations that show great divergence in the expression of this trait. The results of this research support the pre-copulatory mate guarding hypothesis for the adaptive significance of escorting behaviour, and they suggest that conspecific populations vary significantly in the degree or nature of sexual selection acting both on morphology and behaviour of males. Furthermore, in a study of the genetic architecture of escorting behaviour, I found that the observed behavioural variation has a genetic basis: the expression of escorting behaviour is a quantitative trait with a significant sex-related component of inheritance.