Treesearch

Prediction of phenology is an important component of most pest management programs, and considerable research effort has been expended toward development of predictive tools for gypsy moth phenology. Although phenological prediction is potentially valuable for timing of spray applications (e.g. Bt, or Gypcheck) and other management activities (e.g. placement and removal of pheromone traps), we have had a difficult time effectively conceptualizing phenology prediction in GypsES. We have come to the realization that difficulties in representing phenology over a complex topographic landscape,...

Following the 1979 outbreak of gypsy moths Lymantria dispar L. in Vermont, state personnel began monitoring a number of focal areas for signs of increase in gypsy moth populations. In 1986 data from this early warning system indicated an incipient outbreak. We took advantage of this increase to test an experimental management technique. Would disruption of increasing gypsy moth populations at focal sites forestall further expansion of those populations? Four foci were selected, and at each one four one kilometer transect lines were established; one in each cardinal direction, with a 7.5 m...

The sterile insect technique (SIT) and the induced inherited (F1) sterility technique have been investigated for a number of lepidopterous pests, including the gypsy moths. Another technique, backcross sterility, which could potentially prove as or more useful for control of pest species has been developed for the control of only one lepidopteran species, Heliothis virescens. This genetic technique has several theoretical advantages over both SIT and the F1 sterility techniques. In contrast to F1 sterility, backcross sterility can persist indefinitely once introduced into a population....

Propagation of Autographa californica nuclear polyhedrosis virus in cell culture results in the generation of a mutant virus, termed few polyhedra. This plaque variant is characterized by a high budded virus titer, the formation of few polyhedral inclusion bodies (PIBs), and the production of PIBs exhibiting a low potency against its natural host. The isolation and study of a few polyhedra variant of Lymantria dispar nuclear polyhedrosis virus (LdNPV) could lead to a means of enhancing viral potency against the gypsy moth.

Lymantria dispar L. is a polyphagous defoliator that feeds on a variety of trees and shrubs. These hosts vary considerably in their nutritional value for the gypsy moth. Classifications patterned after that of Mosher (1915) are used to group potential hosts into categories that correspond to suitable, marginal, and inadequate. Within species differences in suitability also exist. The role of spatial factors (site effects) and temporal factors (establishment phenology) on the variability of host suitability is examined.

Gypsy moth defoliation is typically observed to occur on xeric ridge tops before more mesic, lowland forest, in oak-dominated habitats in the Northeast. In subsequent years defoliation may also occur in mesic forests. What causes this pattern of defoliation? Differences in the degree of defoliation may be due to differences in the density of gypsy moth populations in these "defoliation-susceptible" and "defoliation-resistant" habitats, with higher densities on ridge tops - the "focal area hypothesis." It is also possible that ridge tops have a lower foliage biomass than mesic forests, such...

Deoxyribonucleic acid from a clonal isolate of LdNPV (CI A2-1), obtained by in vivo cloning procedures, was used to construct genomic libraries in phage (lamda Gem 11) and cosmid (pHC79) vectors. Overlapping clones were selected to generate a restriction enzyme map. The restriction enzyme map, covering about 85% of the CI A2-1 genome, was determined. Efforts are underway to clone and characterize the missing regions.

The Lymantria dispar nuclear polyhedrosis virus LdNPV) is being used as a biopesticide against the gypsy moth. We are attempting to enhance the potency of the LdNPV through recombinant DNA technology. As a prerequisite to genetic manipulation, we have characterized LdNPV gene expression in cell culture through the generation of transcription and translation maps. In addition, LdNPV polypeptides expressed in cell culture were identified.

A recently-developed high resolution climatological temperature data base was input into a gypsy moth phenology model. The high resolution data were created from a coupling of 30-year averages of station observations and digital elevation data. The resultant maximum and minimum temperatures have about a 1 km resolution which represents meteorologically the mesoscale.

We investigated the response of gypsy moth, Lymantria dispar, larval hemocytes to L. dispar nuclear polyhedrosis virus (LdMNPV) administered per os and by injection, and to injected hyphal bodies and natural protoplasts of some entomopathogenic, entomophthoralean fungi.