Gypsy moth, Lymantria dispar, populations were sampled in four eastern North American states during 1991 and 1992 to evaluate levels of hyphomycete infection in association with releases of the Asian gypsy moth pathogen Entomophaga maimaiga. Paecilomyces farinosus was the most abundant hyphomycete species, occurring at the majority of sites, although levels of infection averaged only 4.6% (1991...

Allee effects are important dynamical mechanisms in small-density populations in which per capita population growth rate increases with density. When positive density dependence is sufficiently severe (a 'strong' Allee effect), a critical density arises below which populations do not persist. For spatially distributed populations subject to dispersal, theory predicts that the occupied area also...

Ephemeral disturbances are common in many systems. Often, these brief events are assumed to be a nuisance with little long-term ecological impact. We quantified the impact of the ephemeral forest disturbance caused by gypsy moth canopy defoliation on exotic plant invasion in eight hardwood forests in the Delaware Water Gap National Recreation Area, USA. Six years following the gypsy moth distur...

Gypsy moth is an exotic insect from Europe and was introduced into the United States in the mid 1800s near Boston Massachusetts. The moth spread throughout the Northeast and remained there until the 1930s. The following years saw rapid migration throughout the mid-Atlantic regions. By the 1990s, the moth was found throughout the northeast, mid-Atlantic regions, Michigan, and currently inhabits ...

American chestnut [Castanea dentata (Marshall) Borkhausen], a canopy dominant species across wide swaths of eastern North America, was reduced to an understory shrub after introduction of the blight fungus [Cryphonectria parasitica (Murrill) Barr] in the early 1900s. Restoration of American chestnut by using biotechnology is promising, but the imprecise nature of transgenesis may inadvertently...

Gypsy moth is a major pest in Europe and North America. The closely related species, nun moth, is also a destructive pest in Europe. Both species use the pheromone cis 7(R), 8(5')-2-methyl-7, 8-epoxyoctadecane, (+)-disparlure, for sexual communication. The alkene precursor of disparlure, 2-methyl-7(Z)-octadecene, and (-)-disparlure are also of biological importance in both species. In this thes...

The introduction of the Asian gypsy moth into novel environments continues with frequent interceptions in North America. There is a concern that these subspecies will pose greater threat to forests and urban America than established moths (Lymantria dispardispar L.), due their capacity for female flight. populations vary many key traits, including flight capabilities. potential impacts flight, ...

Disturbance regimes within temperate forests can significantly impact carbon cycling. Additionally, projected climate change in combination with multiple, interacting disturbance effects may disrupt the capacity of forests to act as carbon sinks at large spatial and temporal scales. We used a spatially explicit forest succession and disturbance model, LANDIS-II, to model the effects of climate ...

Cyclic outbreaks of defoliating insects devastate forests, but their causes are poorly understood. Outbreak cycles are often assumed to be driven by density-dependent mortality due to natural enemies, because pathogens and predators cause high mortality and because natural-enemy models reproduce fluctuations in defoliation data. The role of induced defenses is in contrast often dismissed, becau...

Jasmonates, i.e., jasmonic acid (JA) and methyl jasmonate (MeJA), are signaling hormones that regulate a large number of defense responses in plants which in turn affect the plants' interactions with herbivores and their natural enemies. Here, we investigated the effect of jasmonates on the emission of volatiles in the American cranberry, Vaccinium macrocarpon, at different levels of biological...