This study was undertaken to identify, if possible, some morphological characteristics of the U. S. Sitona species that would help simplify the classification of this difficult group. Because of extreme difficulty in obtaining positively identified specimens of all species reported, the scope was limited to eight identified species and one unidentified series. External structures studied include mouth parts, appendages, eyes, wings, and genitalia. The spermathecae were the only internal structures analyzed. Mandibular profiles were compared throughout the species represented and variations were noted. Labia and maxillae were observed but no distinctive differences were noticed. Antennae were found to be quite uniform within the genus. Variations discovered in the thoracic appendages were limited to setae, pollexes, and corbels. These variations, though not too distinctive, appeared specifically consistent. Pollex variation within a species seemed correlated with sex and may well serve as a sex index. Variation of eye size within the genus was relatively large, but within each species it was more or less limited. Prominence of the mesal margins of the eyes followed a similar pattern. Eye characteristics, though consistent, were of a relative nature. Wing structures were found to exhibit great similarity in most respects. General contour and radial cell size and shape were recognized as possible taxonomic characters. The radial cell was emphasized as a wing character because of the ease with which it may be analyzed. The most important morphological taxonomic characters found, in the opinion of the writer, were those pertaining to the terminalia. On the basis of the shape of the apex of the median lobe, the species studied were keyed into two major divisions. Other terminal structures were employed in the key to separate the different species. The key was made to illustrate the ease with which some species may be distinguished. The spermathecae were found to vary around a generic mean. Specific characteristics were not arrived at because of variations. Sixty-seven illustrations were made of the mouth parts, appendages, wings, terminalia, and spermathecae.

This study was undertaken to determine the present status in Utah of the Dipterous family Phoridae, and to report which genera and species are found there. The work was done with the thought in mind of furthering the knowledae of this little-known family in Utah. In order to secure information about the family the writer studied entomological literature and specimens obtained from the entomological collections of the Brigham Young University and Utah State Agricultural College. Personal collecting in various areas of Utah was also done. During the study it was found that there were six genera and twenty-one species correctly identified from Utah. The six genera found were: (1) Phora, (2) Puliciphora, (3) Hypocera, (4) Borophaga, (5) Chaetoneurophora, and (6) Megaselia. Of these genera only two were found to contain more than two species, Phora with six and Megaselia with twelve. Puliciphora and Borophaga both contain two species each, while Chaetoneurophora has one. Hypocera actually has no species since the specimen reported to the writer was identified to the genus only. Megaselia is the only genus to have been reported in the literture, and two species of Megaselia are the only species which have been recorded. The remainder of genera and species, i. e. five genera and nineteen species are written in this study as new records for the state of Utah. Keys to the genera and species of phorida are included to enhance ease of identification. A list of specimens of incomplete and questionable identification is also included in the appendix to serve as a basis for further study.

The writer undertook a preliminary investigation of the taxonomy and geographic distribution of a group of neuropterous insects, the Chrysopidae, in Utah. The main purposes of the investigation were to find what species and forms of these beneficial insects occur in Utah, to provide means for their identification, and to report upon their geographical distribution. Two main methods of investigation were employed. The first, a bibliographic method, was to carefully review the literature concerning the Chrysopidae of the United States for all references pertaining to their distribution and their taxonomy. The second method of investigation was to study insect specimens of Utah Chrysopidae in order to check the findings of former investigators and to add to our knowledge of this group of insects if at all possible. Fortunately, the writer was privileged to study a large number of specimens in the insect collections of Brigham Young University, the University of Utah, the Utah State Agricultural College and Dixie College in addition to his own personal collection. Keys and other taxonomic aids for the identification of the species which have been recorded in the literature as from Utah as well as the species which are recorded as a result of this investigation are provided. The report on geographical distribution is limited in this preliminary investigation to collection records. As a part of this preliminary investigation, the following material is included: (1) a list of species which have been described from surrounding states which may possibly occur in Utah; (2) a history of the study of this group of insects in Utah; (3) a section on the external morphology of the Chrysopidae; (4) a section with information on collecting, preserving, and rearing of these insects and recording of data; and (5) a glossary. It is hoped this supplementary material will aid in the utilization of the report on taxonomy and distribution and will provide a foundation of basic information for future studies of this group of insects.

In this study, the spermathecae of sixty-eight species of Coleoptera, representing fifty-one genera and twenty-three families, were examined and are listed in the order they appear in Leng's Catalogue of the North American Coleoptera. An examination was made of ninety-five specimens of four different species to check for variation within the species. In only one species was there a departure from the pattern characteristic of the genus. Ther spermatheca is differentiated into the cornu, the nodulus and ramus. It is a sac in the female for the reception and storage of the spermatozoa until used for fertilizing the eggs. Among the early workers there was some disagreement as to the origin of the spermatheca. Recent investigators show that it is an invagination fot the venter of the eight abdominal segment. It varies in size, shape and degree of chitinization. In the sub-order Adephaga the spermatheca is generally simple in form and membranous in appearance while in the Polyphaga both simple and complex structures are found. In the genus Aphodius (Family Scarabaeidae) three species were examined. Aphodius fimetarius (L.) and A. distinotus (Mull.) appear to be more closely related than A. fimatarius (L.) and A. granarius (L.). This is contrary to the way they are listed in Leng's Catalogue of the North American Coleoptera. The spermatheca can be a valuable aid in the classification of the Coleoptera, especially in generic and specific separation.

During the years 1950-51 work was begun on a study of the Coleoptera by the author. In 1955, due to the lack of a workable set of keys to the Coleoptera of Utah, a study was undertaken to find a way to more easily classify the beetles of the state to their respective families. The collection of Brigham Young University was used as the basis for determining the families of beetles actually found in Utah. Then a thorough search of the literature was made to find positive records of Utah families not represented in that collection. It was found that of the one hundred two families of Coleoptera (less Rhyncophora) listed for North America by Leng (1920) sixty-nine of them are definitely represented in Utah, with the possibility of adding more to the list when more extensive collecting is done. While two authors studied (Comstock, 1949 and Essig, 1948) place the families of Coleoptera into groups called series of superfamilies according to various structural similarities, few attempts have been made to break down the order into smaller groups for taxonomic work. Even though they mention the superfamilies, no attempt has been made to make keys to these groups. Inasmuch as the order is so large, it would seem advisable to construct a more workable group of keys to the Coleoptera. This would undoubtedly be very beneficial to the beginning Coleopterists, for it breaks an otherwise unwieldy group down into more workable divisions. Also, by limiting this problem to the Coleoptera of Utah, some thirty-one families will be eliminated for, according to records available to the author, they are not represented in this state. Illustrations are used extensively to make it easier for the student to understand the characters used to separate the families or groups of families.

Bionomics of a gall midge that emerged from nodulelike structures of herbaceous sage, Artemisia ludoviciana Nutt., was studied as a part of a larger investigation on possible nitrogen fixation by this plant. Infested plants collected from the field were regularly examined in the laboratory where some of them were grown in a liquid nutrient medium. In the laboratory, adult midges were reared from the pupae and induction of infestation was attempted. Apparent nodulation on these plants is caused by the subterranean bud galls of a previously unknown gall midge species, Rhopalomyia subhumilis Gagne. The life history of this midge is reported. This midge has one generation per year in the study areas and overwinters as larvae. There were no indications of paedogenesis. These midge larvae are parasitised by a species of Platygasteridae.

The population dynamics of Tanypus stellatus in Goshen Bay of Utah Lake was investigated from July 18, 1973, to August 5, 1974. Samples were collected from three stations with an Ekman grab and a K-B corer. The samples were washed in a 110 micron nitex screen and then floated in a sucrose solution. The K-B core was used to determine the vertical distribution of Tanypus stellatus. Ninety-six percent of the Tanypus stellatus larvae are located in the top five centimeters; 99 percent are less than ten centimeters deep. The Ekman grab was used to study the population dynamics of the larvae. The population trends observed are likely true for the entire bay and possibly the lake also. Early instar larvae tend to be contagiously distributed and later instars are more randomly distributed. Two emergence periods occurred. One in July and one in August. Larvae overwintered in the first and second instar. Possible temperature relationships are also discussed.

Egg maturation in insects depends on the uptake of extraovarian proteins, mainly vitellogenin, the hemolymph precursor of vitellin. Vitellin has been shown to be the most abundant protein component of insect eggs, comprising up to 90% of total soluble proteins. It is generally believed that vitellin is essential for egg development. However, a more complex system has been described for several insects. Studies where vitellogenin-deficient Bombyx mori eggs matured in male hosts and proceeded with embryonic and post-embryonic development (Yamashita and Irie, 1980), provide the best example of the complexity that exists in some insect eggs and questions the extent to which vitellin supports egg vital functions. The complex egg composition found in several insect species, is thus worth studying as a possible insect strategy evolved to maximize species fitness. In the lepidopteran, Lymantria dispar, observed behavioral and developmental characteristics of the newly hatched larvae may be correlated with egg quality. The first eggs deposited are larger than eggs subsequently produced, resulting in unequal partitioning of resources. Two major serum and yolk storage proteins (vitellogenin and vitellin), a glycine rich protein of pupal fat body origin, and an egg specific protein, have been isolated and partially characterized in this study. Monospecific polyclonal antibodies to these proteins, in addition to two other major serum proteins (arylphorin and lipophorin) characterized in previous studies, were developed to aid in the determination of protein dynamics during development. The distribution pattern of the major yolk proteins in oocytes along ovarioles of newly emerged females shows a differential contribution towards the egg's composition. In addition, studies of egg samples gathered at different times during development revealed a differential utilization of resources. This apparent diversification and selective utilization of yolk resources might be directly related to the behavioral characteristics of the newly emerged larvae and possibly essential to a species survival as a population in a diverse and changing environment.

The first part of this study examines vaccine candidates for African pathogenic trypanosomes. Nonvariant antigens (NVAs) limited to bloodstream form stages of Trypanosoma congolense, have been identified using immunodiffusion, immunoelectrophoresis, and Western blotting techniques. Results from experiments employing surface biotinylation, iodination, and immunogold labeling suggest that these NVAs are exposed on the parasite surface and thus, if appropriately presented might afford the mammalian host a protective immunity. Trypanosoma brucei brucei development in Glossina provides another opportunity to block parasite development via passive immunization against procyclic forms. Results obtained from studies designed to evaluate this possibility suggest that ingested anti-procyclic antibody had little influence on parasite development within Glossina. The apparent resistance of antibody to enzymatic degradation for up to 120 h postingestion, as determined by Western blotting, suggests that antibody inactivation, rather than destruction is responsible for these results and provides a rationale for future investigations. The second part of this study investigates virulence mechanisms and identifies possible diagnostic antigens of the human urogenital protozoan parasite Trichomonas vaginalis. Plasma membrane isolated from T. vaginalis strains differing in virulence contain qualitative but not quantitative differences in their protein composition as determined with the aid of Western blotting. Two proteins in the 150 kDa range appeared more abundant in mild strains, while proteins of 43 and 25 kDa appeared more abundant in the membranes of virulent strains. These latter proteins are apparently heavily glycosylated as indicated by their ability to bind ConA and SBA lectins. Possibly, these glycoproteins may contribute to virulence mechanisms of the parasite. In attempts to develop a reliable diagnostic assay, soluble antigens shed by T. vaginalis were identified using Western blotting techniques. Five soluble antigens were initially identified in supernatant fluids obtained from parasites grown on TYM medium supplemented with 1% normal human plasma (NHP). Four of these proteins immunologically cross-reacted with NHP and are thus of limited diagnostic potential. A 100 kDa antigen, lacking in NHP cross-reactivity, however, could be isolated from all parasite strains examined and maybe of some use in developing a diagnostic assay.

The purpose of this dissertation was to determine the biochemical mechanisms of azinphosmethyl, permethrin, and abamectin resistance in the Colorado potato beetle (Leptinotarsa decemlineata (Say)) in the hope that this information may be used to construct resistance management strategies. Chromogenic substrates, as well as the in vivo and in vitro metabolism of the three radiolabelled insecticides, were used to determine the metabolic and pharmocokinetic differences of the strains. Azinphosmethyl resistance was due to reduced penetration of azinphosmethyl, increased monooxygenase activity towards azinphosmethyl, and an altered acetylcholinesterase. Monooxygenase activity appears to be the most important mechanism in azinphosmethyl-resistance, but reduced penetration and altered acetylcholinesterase probably have significant roles in the high level of azinphosmethyl-resistance in CPB. Permethrin-resistance appears to be due to increased carboxylesterase activity and site-insensitivity. An increased level of carboxylesterase activity was apparent from a higher $V\sb{max}$ towards carboxylesterase substrates and increased hydrolytic metabolites of permethrin. This carboxylesterase is membrane-associated. An isogenic permethrin-resistant strain was determined to be cross-resistant to DDT, indicating site-insensitivity was another mechanism involved in permethrin-resistance. Abamectin-resistance in two strains was determined to be polygenic. Both strains exhibited high levels of synergism to PBO and moderate levels to DEF. Both strains had elevated levels of cytochrome P450 and oxidative abamectin metabolites in vivo and in vitro. This is the probable reason for the higher levels of excreted compound in the abamectin-resistant strains. Carboxylesterase activity was greatly increased in the abamectin-resistant strains. Carboxylesterases may hydrolyze or sequester abamectin in the resistant strains.