An experimental study of laboratory populations of the stored-products moth, Cadra cautella (Lepidoptera: Phycitidae) and its larval parasitoid, Venturia canescens (Hymenoptera: Ichneumonidae) identified and quantified density- and age-dependent demographic characteristics of the host-parasitoid system. Host imago longevity and fecundity depended on larval weight at pupation. Observed effects of C. cautella larval competition for food on larval mortality, stage duration, and weight at pupation were successfully captured in a mathematical model. Host larval age significantly influenced inter-stage cannibalism and susceptibility to mortality resulting from parasitoid oviposition wounds. Both larval parasitoid developmental rates and adult parasitoid attack rates depended on host larval age. Long-term population experiments of host and host-parasitoid populations revealed that host populations fluctuated with a period slightly in excess of host generation time and that parasitoid populations were in synchrony with host populations.

Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 104-110).

Thesis (M.Sc.-Res.)--University of Wollongong, 2008. / Typescript. Includes bibliographical references: leaf 70-92.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 76-84).

No description available.

Hemolymph trehalose concentrations of male and female Heliothis zea were quantitated by high performance thin-layer chromatography (HPTLC) at various ages and times of the day and related to flight activity. Effects of octopamine injection or stress on trehalose levels were also quantified. Flight activity was measured with a 32-channel computerized actograph that simulated sunrise at 0300 EST (Eastern Standard Time) and sunset at 1700. Males exhibited greater flight activity than females at all ages examined. Flight began near sunset, continuing through the night and ending around sunrise. Females flew continuously throughout the night, whereas males exhibited two peaks in activity: the first between 1700 and 1900, followed by a second peak between 2000 and 2400. Flight activity peaked on days 3-4 in males and days 4- 5 in females. Trehalose was the predominant hemolymph sugar, comprising 82-100% of total hemolymph sugars. Glucose was the second most frequently observed sugar. Trehalose concentrations were variable, ranging from < 1 ug/ul to 37 ug/ul. Lab-reared moths had higher and more variable trehalose concentrations than field collected (wild) moths. Trehalose levels were relatively constant several days after emergence in both sexes but decreased significantly by day 6 in males. When examined over a 24 hour period, trehalose concentrations gradually increased throughout the day in day 4 males and females, peaking one hour before sunset at approximately 18 ug/ul. This peak is hypothesized to be related to flight preparation. Females showed a second peak in trehalose levels at 1800, but males’ trehalose levels continued to decline until 1900. Males and females exhibited more similar patterns in trehalose concentrations when sampled every 15 minutes over the sunset period (1500-1900) than when sampled at hour intervals. Injections of octopamine, reputed to induce hyperglycemia in other insects, failed to elicit significant increases in trehalose levels in either fed or starved moths. Starved moths had lower trehalose concentrations than fed moths. Method of analysis (HPLC, HPTLC and anthrone) produced no differences in measured levels of trehalose or glucose. Various forms of stress (handling, shaking), also reported to induce hyperglycemia in other insects, similarly did not significantly increase trehalose titers in moths. / Ph. D.

1. The pear borer is widely distributed in the eastern part of this country. 2. The abdominal cavity of the female was filled with eggs. 3. The incubation period of the eggs averaged 5.6 days at a mean temperature of 76.2 degrees F. 4. The larvae fed mainly on the inner bark and cambium of the trees, but occasionally burrowed slightly into the sapwood. 5. There were six larval stages. 6. Larger larvae devoured smaller larvae on contact with them. 7. Around 85 percent of the borers have a one-year life cycle. 8. The winter was passed by the larva in a silken hibernaculum constructed in the burrow. 9. The pupa was strongly chitinized, and the abdomen was armed with large spines. 10. The pupal stage averaged 23.0 days for the males and 17.44 days for the females. 11. The moths were most active and most of the eggs were deposited between 2:00 and 4:00 p. m. 12. On the female moth there was more yellow than on the male. 13. The average length of life for the males was 4.46 days and for the females 4.96 days. 14. In the andrews orchard 50 to 100 borers per tree were not unusual. 15. The apple is the main host plant of the larvae in Virginia. 16. About 99 percent of the moths emerged between May 15 and July 10. 17. The male moths emerged several days before the female. 18. The females had deposited 33 percent of thelr eggs when they were captured in the bait-pails. 19. The pear borer is sometimes rather extensively attacked by hymenopterous parasites. 20. The borers may be removed with a sharp hawk-bill knife in the fall or early spring. 21. In heavily infested orchards, bait-pails would be economical and quite effective in reducing the number of moths present in the orchard during May and June. 22. The common insecticidal sprays are not effective in killing the larvae. 23. Paradichlorobenzene dissolved in cottonseed oil, white mineral oil, and pine tar oil and applied to the trunks and larger limbs of the trees with a paint brush gave excellent results without injury to the tree. / Master of Science

The ovicidal properties of various vegetable, animal, and mineral oils were tested in an effort to develop a supplementary method of control for the codling moth and the oriental fruit moth. The reasons for undertaking this problem are twofold: first, the codling moth has become exceedingly difficult to hold in check; and, second, in the case of the oriental fruit moth there is no satisfactory method of control. The studies could be carried on with both insects because they are very closely related and also, because the oriental fruit moth is a pest of apples as well as peaches. / Master of Science

A decline in biodiversity in agricultural landscapes has been reported for decades. One of the most important habitats for biodiversity in agricultural landscapes is semi-natural grasslands. To preserve species-rich semi-natural grasslands, research need to focus both on local habitat quality and on landscape composition at various scales. In the current study I examined how nectar sources, host plants and other environmental parameters affected the occurrence of adults of four burnet moth species, residents of semi-natural grasslands. Also, I investigated the effects of landscape composition at 34 spatial scales. The results in general showed positive effects of host plants cover, nectar sources abundance, dry soil, sun exposure, tall sward height, small herb and grass cover. At the landscape level all the species responded negatively to the amount of arable land and positively to the amount of forests at scales up to 10000 m. Two species were negatively affected by the amount of artificial surfaces and pasture at some scales. Though the amount of semi-natural grasslands and patch area did not affect the occurrence of the species, at the local scale semi-natural grasslands were still important for the species. Thus, my results suggest that management should be focused both on local and landscape levels. Focus should be to preserve sunny and open areas of high-quality semi-natural grasslands rich in burnet moths’ host plants and especially nectar sources that seem to be more important than host plants for adults. Semi-natural grasslands should be preferably adjacent to forests and not arable land.

No description available.