Thesis (Ph. D.)--University of Wisconsin--Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 169-186).

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Experiments were conducted to refine and validate the soybean looper, Chrysodeixis includens (Walker) threshold in Mississippi soybeans, Glycine max. (L.) Merr. Equivalencies between sweep net and drop cloth sampling methods were evaluated, overall the sweep net was more effective at capturing soybean looper larvae greater than third instar and larvae less than or equal to third instar when compared to the drop cloth method. Feeding studies were conducted to determine the feeding rates of each instar, results showed that fifth instar larvae consume the greatest amount of leaf tissue, and larvae greater than or equal to third instar consume more leaf tissue than larvae less than third instar. Observed and expected/predicted defoliation rates were calculated. Observed defoliation was lower than predicted defoliation possibly due to field environmental conditions. Using data in combination with published data from other studies, three prediction models were created for the R3, R5, and R6 growth stage.

Three criteria, development, flight, and oviposition, were used to compare a laboratory-adapted and wild-type colony of Trichoolusia ni. The laboratory-adapted colony was further examined to determine the effect of larval crowding and starvation on the above criteria. The laboratory-adapted colony displayed a shorter development time and higher immature mortality than the wild-type colony. Differences in flight activity between and within the colonies were observed. Wild-type mated females were the most active group of tested moths. The oviposition rate of the laboratory-adapted colony was higher than the wild-type colony. Innate differences in parent populations and selective pressures during the rearing of the laboratory-adapted colony may explain differences between the colonies. Larval crowding resulted in prolonged development time, lower pupal weight, increased larval mortality, and increased adult longevity. Starvation during the larval stage produced similar changes. Flight activity declined with the degree of larval crowding and starvation. Larval crowding and starvation also resulted in a decline in adult fecundity and mating frequency. It is postulated that stress to the larvae resulted in a decline in energy sources to be used in the adult stage, producing docile adults. / M.S.

Thesis (M.Sc.), Memorial University of Newfoundland, 2000. / Restricted until June 2001. Bibliography: leaves 69-74.

Possible effects of steady low strength magnetic fields on insects were studied using the cabbage looper moth, Trichoplusia ni (Hubner). In the first tests, adult loopers were used to determine their locational preference in response to areas of stronger or weaker magnetic field ranging from slightly above the geomagnetic field strength to a strength of 120 gauss. In a second series of tests, looper eggs were continuously exposed to steady magnetic fields of various strengths ranging from 10 to 1850 gauss. In a third series of tests t individual adult loopers were exposed to a steady 500 gauss field for five minutes. Oxygen consumption was monitored to indicate the level of moth activity before, during, and after this exposure. Results of the tests conducted revealed no effect of low magnetic fields on moth locational preference, egg hatchability, or activity level. / Master of Science

Soybean looper and corn earworm are economically damaging pests in Mississippi soybeans. Chemical control plays a large role in the control of these pests. Some producers have started applying an automatic co-application of insecticide and fungicide at the R3 growth stage. Insect growth regulators are a commonly used insecticide for this management strategy. The purpose of this research was to evaluate the impact of insect growth regulators on soybean looper and corn earworm mortality when applied with an automatic fungicide application at the R3 growth stage in soybean. Insecticide treatments included methoxyfenozide, diflubenzuron, and novaluron. These insect growth regulators showed very little control and mortality, especially when compared to chlorantraniliprole, which has become an industry standard for control of lepidopteran pest control of in soybean. The automatic application of an insect growth regulator insecticide with a fungicide at the R3 growth was not viable for economic insect management strategies.

The roles of ocelli and octopamine in regulating the onset, intensity, and duration of cabbage looper moth flight activity were examined. This was achieved by studying the flight activity of control, sham, and anocellate moths with and without octopamine treatment. Sham and anocellate moths were produced by cauterization in last-instar larvae, of ocellar primordial cells for anocellate moths, and of non-involved cells for sham moths. Flight activity of moths was monitored by a computerized actograph under normal light (LD) conditions, under advanced-sunset, and under constant dark (DD) conditions to determine the effect of ocelli on flight activity. The role of octopamine was investigated by treating the three groups of moths topically with octopamine dissolved in dimethyl sulfoxide (DMSO) and with DMSO alone, and comparing flight activity before and after treatment. Results support a combined role for ocelli and the compound eyes in determining flight initiation times, and a role for ocelli in determining flight intensity. These roles were more pronounced in males than in females. It was found that the cauterization operation itself decreases flight activity in sham moths. No evidence was found that supports the existence of an octopamine effect on flight activity in any of the groups of moths when octopamine is topically applied. / Master of Science

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Thesis(M.S.)--Auburn University, 2006. / Abstract. Vita. Includes bibliographic references (p.93-105).