Call number: LD2668 .T4 1957 G73 / Master of Science

Call number: LD2668 .T4 1957 O95 / Master of Science

No description available.

Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Feb. 6, 2009). Includes bibliographical references (p. 66-68).

A laboratory colony of a multi-insecticide susceptible strain of the housefly, Musca domestica was challenged with continuous larval selection pressure equivalent to the initial LC 60 level for 8 generations with the insect growth regulator WL 86303 (1-(3,5-dichloro-4)4-nitrophenoxy- phenyl)-3 -(2)chlorobenzoyl)- urea). A more than twofold increase in resistance was observed at the F8 generation. No cross-tolerance to the related compound, diflubenzuron (DIMILIN (R)) (1-(4-chlorophenyl)-3- (2,6-difluorobenzoyl)-urea) was observed after 8 generations. WL 86303 was significantly less toxic to houseflies than diflubenzuron. No significant difference was noted between the toxicity of WL 86303 to an unpressured wild housefly strain, and to the unselected multi-susceptible strain. A larval-rearing bioassay technique for measuring the toxicity levels of juvenile developmental disruptors is described.

No description available.

Call number: LD2668 .T4 1979 S73 / Master of Science

No description available.

Laboratory and field studies of Hydrotaea aenescens were undertaken to provide information on this predator's biology and ecology under differing conditions, and to promote its use as a biocontrol agent for controlling house flies in poultry houses. Taxonomic diversity of arthropods in a new high-rise cage layer poultry house was determined from manure samples collected from different manure moisture categories. Stabilization of taxonomic diversity and taxonomic evenness of manure-inhabiting arthropods occurred after the house had been operating for eight months. In contrast, overall diversity in high-rise poultry houses at a well managed, longer established farm was significantly higher than that observed at the new farm, even after 1 1/2 years of operation. When the densities of selected manure-inhabiting predatory arthropods collected from the manure samples (including Carcinops pumilio, pseudoscorpions, a dermapteran species, an anthocorid species, and H. aenescens) were correlated with percent manure moisture, the results showed that, of these predators, only H. aenescens was positively correlated with both manure moisture and with densities of house fly larvae. This information emphasized that although predators such as C. pumilio may exhibit high predation rates on house fly eggs and first instars, their effectiveness 1s reduced by their spatial separation from their supposed prey. This contrasts greatly with H. aenescens performance. Decreases in survival of house fly larvae occurred when the larvae were exposed to H. aenescens of higher larval stadia. This was dramatically demonstrated when 100 first instar house flies were exposed to 100 second instar H. aenescens. No house fly larvae survived. Developmental times were determined at constant temperatures for egg, and larval H. aenescens. Developmental times decreased as temperature increased. Median time for egg and larval development ranged from 1.3 and 14.6 days at 22.2°C to 0.5 and 8.3 days at 35.0°C, for the respective stages. All of this information, together with developmental times and mortality of H. aenescens immatures gathered in a study of temperature dependent development has enhanced understanding of the biotic interactions in accumulated poultry manure. These data will be invaluable in designing integrated pest management programs especially in the area of computer-aided decision making. / Ph. D.

Effects of electrostatic fields on insects were studied using cabbage loopers, Trichoplusia ni (Hubner) and houseflies, Musca domestica L. Two series of tests were conducted; one to determine the electrostatic field effect on the locational preference and the other to determine the field effect on wingbeat. Among the field gradients examined (250, 500, 750, 1000, 1250, 1500 v/crn), those with 750 v/cm and up had significant influence on the locational preference of houseflies at the five percent significance level. With a choice between two regions, having no field and with field at an e.f.i. of 750 v/cm, houseflies preferred to be in the field. For gradients above 750 v/cm the houseflies preferred the region with no field. Electrostatic fields with gradients 500, 750, 1000, 1250, and 1500 v/cm had significant effect on the wingbeat frequency of male cabbage loopers and no effect on females. The change in wingbeat among males was found to increase linearly with increasing e.f.i. Removal of part or full antenna did not effect the response of loopers to electrostatic fields. / Master of Science