This study determines the number of families of Hemiptera found in the state and has a key for their classification. The characteristics and general distributions of each family are given, along with specific examples of the most common and economically important bugs. Important references are given for each family of work done to date. It was found that there have been twenty-eight families of Hemiptera collected in Utah, some of which are well represented in numbers of genera, species, and individuals, while others are represented by a single species and collected in only one or two places in the state.

Culex tarsalis Coquillett is a common evening pest mosquito throughout the summer in most of temperate Western North America. Present evidence indicates this mosquito as the principal naturally infected vector of western equine encephalomyeltic (WEE) viruses. Certain interrelationships of WEE epidemiology and tarsalis bionomics are basically understood; however, in areas where winters are severe little is know of tarsalis hibernation, and the survival mechanism for WEE viruses in unknown. The purpose of this study, conducted from 1 September 1959 to 20 May 1960, was to gather ecological information on the hibernation of Culex tarsalis in Utah Valley, and secondly to collect pools of hibernating tarsalis and determine the index of infection, in any by WEE viruses.

Considerable research on ticks has been done since it was discovered that the Rocky Mountain wood tick, Dermacentor andersoni Stiles, was a principal vector of Rocky Mountain spotted fevero Additional disease agents of man are also transmitted by D. andersoni. This tick and a closely related species, Dermacentor parumapertus Neuman, occur commonly in Utah. The two species are often closely associated, although D. andersoni is believed to occur in the mountains, whereas D. parumapertus is in the desert valleys. Diseases affecting animals in nature are transmitted by ticks of both species. Consequently, any interaction between the two may be influential in the maintenance of diseases in nature communicable to man and his domestic animals.

Three predominant and economically important shrubs of the sagebrush-grass range community in Utah, namely big sagebrush (Artemisia tridentata Nutt.), rubber rabbitbrush (Chrysothamnus nauseosus (Pall.) Britt.), antelope bitterbrush (Purshia tridentata (Pursh) DC), and a widely re-seeded range grass, crested wheatgrass (Agropyron cristatum (L.) Gaertn.) were sampled during the summers of 1966 and 1967, and yielded twenty species of thrips. Three species (Anaphothrips tricolor Moulton, Chirothrips aculeatus Bagnall, Chirothrips simplex Hood) were new distributional records for Utah. Seven species (Frankliniella n. sp. #1, Frankliniella n. sp. #2, Haplothrips n. sp., Leptothrips n. sp., Oedaleothrips n. sp., Sericothrips n. sp. #1, Sericothrips n. sp. #2) were undescribed. Six species (Anaphothrips zeae (Moulton), Aptinothrips rufus (Gmelin), Chirothrips aculeatus Bagnall, Frankliniella minuta Moulton, Frankliniella occidentalis (Pergande), Thrips tabaci (Lindeman) had previously been reported as injurious to various range and agricultural hosts. The remaining species included: Aeolothrips duvali Moulton, Aeolothrips fuscus Watson, Aptinothrips rufus stylifera Trybom, Haplothrips sonorensis Stannard, and Rhopalandrothrips corni Moulton. Host preference, habitat preferences, and peaks in seasonal abundance were determined for each thrips whenever possible.

Indian ricegrass at the Desert Range Experiment Station forty-seven miles west of Milford, Utah, is damaged by the larvae of Coenchroa illibella, Diatrae sp. and Typoceris ceraticornis, the latter being the most destructive. The biology of the insects and the extent of damage inflicted are discussed. Uninfested plants produced more new stems than infested plants. Plants having a basal diameter of 4 to 6.9 cm and 7 to 9.9 cm were the most frequently infested and, consequently, the most severely damaged.