Lymantria mathura Moore is a polyphagous defoliator of hardwood trees in the Russian Far East, Japan, India, and China. Its egg masses were intercepted on ships arriving to Pacific Northwest. If introduced and established in North America, L. mathura is likely to cause serious economic consequences. As a part of a program for development of monitoring and control measures, possible host range, larval air-borne dispersal, mating behavior, and pheromone communication of L. mathura were studied. Survival and development of first instars of L. mathura were examined on 24 hardwood and conifer tree species from North America, Europe, and Asia. Lymantria mathura performed well on hosts in the family Fagaceae. Survival and growth rate was high in the genus Fagus (beech) and Quercus (oak), particularly white oak group. Performance was intermediate on species of red oak group and species from Juglandaceae, Betulaceae, and Oleaceae. Survival was poor on Pinaceae. Dispersal rates, settling velocities, and diel periodicity of dispersal for both L. mathura and Asian L. dispar were studied to predict probable extent of neonate dispersal. Dispersal rates for L. mathura exceeded those of Asian and North American gypsy moths. Neonates of L. mathura weighed less and had slower settling velocities than Asian or North American gypsy moths. Pheromone-baited traps would be important for detecting introductions of L. mathura, but a sex pheromone has not yet been identified. I studied the olfactory reaction of males to females and to odor compounds in the wind tunnel. Number of males performing searching flight in a pheromone plume was lower than moths performing non-pheromone mediated flight. There was no difference in male performance when stimulated with preparations of female abdominal tip extracts or synthetic compounds derived from females. Studies of courtship showed that females initiated calling shortly after start of scotophase, and courtship occurred several hours later. Mating occurred after a calling female starts wing fanning, initiating a fanning response and flight in a nearby male. A receptive female lifts the wings and allows a male underneath. During behavioral studies, low frequency atonal sound associated with wing fanning was recorded in both sexes of L. mathura, and several other lymantriids tested for comparison. There were differences in wing beat frequencies between sexes and species.

Gravids preferred oviposition sites that contain larvae over those that contain only water. The degree of preference increased with increasing larval instar, and also increased with increasing larval density up to a density of 2 larvae per ml. At higher densities the response became negative. Larvae act as indicators of site-suitability, and may indicate imminent competition at high densities, regardless of the presence of contaminating microfauna. Gravids rely on olfactory and chemo-tactile cues to detect the presence of larvae at oviposition sites, with a greater reliance on olfactory cues. Visual cues are unimportant in the detection of larvae. Gravids avoided ovipositing in a site already harboring eggs. This negative response increased with increasing egg density. Eggs are indicators of direct competition in the larval habitat. This avoidance reaction is mitigated by both olfactory and chemo-tactile cues. That egg distribution did not affect subsequent oviposition suggests the chemo-tactile response is more likely due to local concentration of chemicals than due to direct contact with eggs. Females visit more smaller sites when all available oviposition sites are identical, and lay fewer eggs in smaller treatment sites, than they do compared to larger sites. The gravid response is independent of substrate surface area and water volume. Eggs were not distributed differently in oviposition sites of different size but equal diameter, suggesting females may select different size-sites based on water surface area. Size is probably an indirect measure of available resources. The oviposition response does not vary with either chronological age of the gravid, nor with her gonotrophic cycle. Females separated in age by 2 weeks in post-emergence age or by 2 gonotrophic cycles responded to oviposition sites in the same manner. Oviposition behavior is flexible but does not take into account a female's relative fitness. The response to oviposition sites containing an attractive density of larvae was further investigated. Females could not discriminate between control and treatment sites in a wind tunnel, even when released but 22 cm from the attractive treatment. The olfactory cues associated with larval rearing habitat act as close range oviposition attractants.

Dispersal and reproduction of the Colorado potato beetle, Leptinotarsa decemlineata (Say), with and without Bacillus thuringiensis subsp. tenebrionis Cry3 A δ-endotoxin in the environment were investigated through a series of field and laboratory studies. Possible implications for resistance management are discussed. Mating behavior of post-diapause beetles was observed. The influence of spring mating on beetle flight was investigated using a flight mill system. The beetles mated at the overwintering site, as well as in the potato field, and in the fields rotated out of potatoes. Mating status did not affect beetle flight, while absence of food encouraged flying over long distances. Dispersal of the summer-generation beetles was studied using a mark-recapture method. Effect of female age at the time of mating on the production of viable offspring was tested in the laboratory. Flight behavior of mated and unmated beetles was quantified on a flight mill. About 25% of the beetles remained close to the site of their pupation when they reached sexual maturity. Beetles produced viable offspring only if they accumulated at least 34 DD before mating. The largest number of flights was recorded for the unmated females. Use of phosphoglucomutase allozymes separated by cellulose acetate gel electrophoresis as genetic markers showed that sperm precedence in the Colorado potato beetle was incomplete, with about 72% of the larvae fathered by males at the second mating. A flight mill system was used to determine the effect of feeding on transgenic potato foliage, potato foliage treated with δ-endotoxin, and regular potato foliage on the flight of full-sib beetle families. Feeding on transgenic foliage had a strong negative effect on beetle flight. The beetles from the families that performed the longest flights when fed on regular foliage performed the shortest flights when fed on transgenic foliage. Laboratory experiments were conducted to compare relative fitness of beetle strains resistant and susceptible to δ-endotoxin. Net replacement rate, intrinsic rate of population increase, overwintering survivorship, and male mating capability were reduced for the resistant strain. Mortality, fecundity, and flight of the same strains were tested under laboratory conditions after beetles were fed on transgenic potato foliage, regular potato foliage, and regular potato foliage followed by transgenic foliage. Both strain and treatment had pronounced effects on the tested parameters, values for which decreased when the beetles were allowed to feed on regular foliage prior to a toxin ingestion.

No description available.

No description available.

No description available.

The cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae), is a serious pest of cranberry (Vaccinium macrocarpon Ait.). Reported hosts also include highbush blueberry ( Vaccinium corymbosum L.), lowbush sweet blueberry (Vaccinium augustifolium Ait.), and black huckleberry [(Gaylussacia baccata (Wang.) K. Koch], all of which grow in the woodlands (called uplands) surrounding Massachusetts bogs. Since a thorough understanding of movement patterns of a pest species within and between host habitats is crucial for the implementation of a successful management program, moth movement was studied in time and space through trapping of wild and mark-released moths. The results, reported in Chapters I and II, demonstrate that the moth is very mobile and that large flights occur in both cultivated bogs and their surrounding uplands. Trap studies also showed a significant effect of trap height on the number of moths captured. Moths were active later at night in the upland, and males, in particular, were active in the trees, which suggested adoption of a “hilltopping” strategy to enhance their chances of mate finding. In field and lab studies reported in Chapter III, the periodicities of emergence, mating, and oviposition were recorded, and the data suggest that it is advantageous for females to delay mating when conditions are favorable for oviposition. Females were polyandrous, and assessment of spermatophore age in females suggested that mating may occur more frequently in the upland compared to the bog. Studies reported in Chapter IV showed that moth activity and infestation occurred earlier in both blueberry plantings and in the uplands than cranberry. The large numbers of moths captured in the uplands did not appear to originate from larvae developing in the uplands, since infestation of wild berries could not be corroborated. A study of host preference and performance in four different hosts (cultivated cranberry and blueberry, wild blueberry and huckleberry) is reported in Chapter V. Huckleberry was the least preferred for oviposition, and both of the cultivated berries were more suitable for larval development when compared to the wild hosts. The relationship between preference ranking and performance was positive. Implications of these findings are discussed.

A newly discovered, nonoccluded baculovirus GSV has been reported to be a causative agent of sterility in adult corn ear-worms, Helicoverpa zea. Previous studies conducted by Hamm et al. (1996) and our laboratory indicated that it is an unusual insect virus with strict tissue tropism and the ability to establish persistent infections in vivo. After acquiring purified virus from infected adult insects, two permissive cell culture systems, TN-368 and Ld652Y were established for GSV replication in vitro. The cell culture-derived virus was confirmed to have the same morphology, biological activity and genetic identity as that of GSV recovered from insects. Using a cell culture system, several genetically pure GSV cloned isolates were acquired by plaque purification. The replication cycle of the virus including ultrastructural studies, viral DNA replication and virus specific protein synthesis were investigated in these two cell lines and interestingly, it was found that the exact same virus isolate had a different biology in the different permissive cell lines. Difference in the molecular biology of virus replication in these two cell lines was also observed. This suggests that host factors play an important role in determining the different host-viral interaction of the virus. In addition, biochemical properties of the GSV genome were investigated. The genome size was estimated using pulse-field gel electrophoresis to be 215-235 kb. CsCl-EtBr density gradient centrifugation indicated that GSV has a supercoiled, circular genome. Purified viral structural proteins, envelope proteins and glycoproteins were analyzed by SDS-PAGE and a total 16 of viral structural proteins were identified, three of them are glycosylated and five of these proteins are likely to be virus envelope or matrix components. Studies of GSV specific protein synthesis, DNA replication and transcription in the presence of specific inhibitors suggests that as with other most baculoviruses, GSV gene expression is temporally regulated and can be separated into early and late phases based on viral DNA replication and differential responses to the cellular RNA polymerase inhibitor, alpha-amanitin. That is, early gene expression is likely mediated by cellular RNA polymerase whereas a viral encoded or viral-modified host RNA polymerase likely mediates late viral gene expression. GSV persistent infection in vitro has been investigated using a persistently infected cell line, GSVP. GSV viral sequences and a very low level of infectious virus were detected from this normal-looking, persistently infected cell line. Co-culture of GSVP cells with another permissive cell line, Ld652Y, resulted in productive replication of GSV.

Comparative cytological and molecular phylogenetic data suggest that amitochondriate trichomonads (Archaeprotista: Parabasalia) are an early branching lineage of eukaryotes. Prominent in their cells is the karyomastigont, a cytoskeletal organellar system that includes a nucleus, 4–5 kinetosomes, an axostyle, a parabasal body (Golgi complex), and associated fibers. The karyomastigont is an ancestral character of eukaryotes. Genera of the trichomonad family Calonymphidae (Calonympha, Coronympha, Metacoronympha, Stephanonympha and Snyderella) are polymastigont: multinucleate cells with many karyo- or akaryomastigonts (karyomastigonts that lack nuclei). Termite hindgut trichomonads were examined for their susceptibility to antibiotics, pattern of cell division, and to test the hypothesis that DNA is associated with centriole-kinetosomes. Several types of bacterial symbionts are harbored on the surface membranes, in the cytoplasm and nuclei of these anaerobic protists rendering them susceptible to antibacterial antibiotics. Caduceia sp., a devescovinid trichomonad with four types of bacterial symbionts, was removed within 14 days from the Cryptotermes cavifrons (Florida) gut when penicillin and streptomycin were fed to the termite. Snyderella tabogae was far less susceptible to the antibiotic treatment, which also enhanced formation of calcium-rich crystals in the intestine. Metacoronympha divides asymmetrically. M. senta from Incisitermes nr. incisus (Trinidad) also showed a bimodal distribution of cell size. Approximately one third of the population averaged 100 μm in length with as many as 1000 karyomastigonts, unlike the previously described 50 μm mean length with up to 350 karyomastigonts. The cytoskeleton of Snyderella tabogae, the only calonymphid whose complete set of nuclei are not attached to centriole-kinetosomes, consists solely of 500 or more akaryomastigonts (>2000 undulipodia and their kinetosomes). In Snyderella tabogae, groups of 20–50 akaryomastigonts simultaneously beat and form locally organized regions of the cortex. These polymastigont cells are ideal to seek centriole-kinetosome-associated DNA. Fluorescent cytological (DAPI, SYTOX, acridine orange, ethidium bromide, propidium iodide) as well as Feulgen stains were negative: no DNA was present in the centriole-kinetosomes of S. tabogae. However, DAPI accumulates in the parabasal bodies (Golgi complex).

North American gypsy moth disperse as larvae on the wind in a behavior called ballooning prior to feeding for the first time. Resources used in dispersal are therefore limited to those carried over from the egg. I measured levels of two yolk storage proteins, vitellin (Vt) and glycine-rich protein (GRP), using quantitative immunoelectrophoresis, I determined the tendency of larvae to balloon in a wind tunnel. I estimated the length of the window for dispersal from the longevity of unfed neonates. Pre-hatch levels of Vt and GRP had no influence on the tendency of neonates to balloon. Levels of these proteins were positively associated with and accounted for 40-50% of the variation in longevity of neonates from the first-laid and center thirds of egg masses. Longevity was greatest for neonates from the first-laid third which also had the highest pre-hatch levels of Vt and GRP. Nutritionally stressed females compensated to maintain levels of Vt and GRP by reducing the number of eggs produced. This compensation was reflected in similar longevities of offspring of stressed and unstressed females. The tendency of larvae to balloon, however, was greater in offspring of unstressed females. It is possible that traits selected for in nutritionally stressed females may be expressed in offspring as a reduced tendency to disperse. Temperature during the six weeks prior to eclosion had a significant effect on pre-hatch levels of Vt and GRP and on neonate longevity. Eggs held at 7$\sp\circ$C or less had similar pre-hatch levels of both proteins. Eggs held at 10$\sp\circ$C for six weeks, however, were depleted of Vt and GRP suggesting a threshold between 7 and 10$\sp\circ$C for stimulation of protein utilization. Eggs held for alternating weeks at 4 and 10$\sp\circ$C had protein levels similar to eggs held at 4$\sp\circ$C indicating eggs must be exposed to temperatures above the threshold for a period greater than a week before utilization of proteins is increased.