Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 63-70).

Doctor of Philosophy / Department of Entomology / Franklin Arthur / James R. Nechols / The Indianmeal moth, Plodia interpunctella Hubner, is capable of infesting a number of different commodities including a wide variety of grains, nuts and finished stored products. Therefore, control of the Indianmeal moth is especially needed in areas where food is being stored for human consumption. Increased concerns of consumers and producers regarding the impact of conventional insecticides on the environment and on human health has prompted scientists and the agricultural chemical industry to search for insecticides that do not affect mammalian nervous systems and have limited effects on non-target organisms. One group of insecticides with reduced risks is insect growth regulators (IGRs), which are substances that mimic insect hormones essential to normal development and reproduction. Currently methoprene, a juvenile hormone analog, is labeled for direct application to stored grains, as well as a contact insecticide and as an aerosol application inside mills, warehouses, and indoor food storage facilities. Surface treatments and aerosol space applications can be effective ways to treat the interior surfaces and storage areas of warehouses and food processing facilities. There is little recent research with large-scale aerosol applications in storage sites; furthermore, there are no published references in the scientific literature regarding efficacy of using methoprene alone in aerosol form. Therefore, the purpose of this research was to evaluate the use of surface and aerosol applications of methoprene on finished stored-product packaging materials and facilities for the control of P. interpunctella. Results of this research showed that while methoprene has good residual activity, and efficacy is unaffected by temperature, surface applications of methoprene on packaging materials is not as effective for control of P. interpunctella as aerosol applications of methoprene. Aerosol methoprene is highly effective alone and in combination with conventional chemicals for control of eggs and wandering-phase larvae. Simulations with a population growth model make it possible to estimate impact of insecticide treatments at different temperatures and application times on populations of P. interpunctella. Aerosol treatments are also economically viable as part of an overall integrated pest management program.

Master of Science / Department of Entomology / Frank Arthur / The control of Indianmeal moth [Plodia interpunctella (Hübner)], a commonly found serious stored product pest around the world, relies mainly upon chemical control methods. Because of recent changes in the laws and regulations governing pesticide usage in the United States, there is an increasing need for finding safer chemicals to control insect pests. Hydroprene, an insect growth regulator, is considered to be a safe alternative. In this study, I quantified the effects of hydroprene on two critical life stages of Indianmeal moth, the eggs and 5th instar wandering phase larvae. Maximum development time in the untreated controls was 13.6 ± 0.6 d at 16°C and minimum development time was 2.3 ± 0.4 d at 32°C. At 20°C and 24°C, the effect of hydroprene on egg development became more evident; development time generally increased with exposure interval, with some variability in the data. The mean egg mortality among all temperatures was 7.3 ± 4.6%. Among the treatments, mortality of eggs increased as the exposure periods increased within any given temperature, with a dramatic increase in mortality with increase in temperature. Egg mortality was lowest at 16°C when exposed for 1 h (0 ± 3%), but mortality gradually increased up to 32 ± 3% when exposed for 18 h. Within each exposure interval, there was a direct increase in mortality as the temperatures increased. For the 5th instar wandering phase larvae, the longest development time among the treatments of 47.2 ± 1.3 d occurred at 16ºC when the larvae were exposed for 30 h, whereas the shortest development time of 7.0 ± 0.5 d occurred when the larvae were exposed for 1 h at 32ºC. Among treatments, the greatest larval mortality (82.0 ± 0.1%) occurred when larvae were exposed for 30 h at 28ºC, while the minimum mortality of 0.0 ± 0.5% occurred at 16ºC when larvae were exposed for 1 h. Response-surface models derived from this study can be used in simulation models to estimate the potential consequences of hydroprene on Indianmeal moth population dynamics.