Alien Species, Agents of Global Change : Ecology and management of the Gypsy Moth in North America as a case History

USDA Forest ServiceScedule:17-18 March 2003, Vemue: Kanazawa, Japan, Kanazawa Citymonde Hotel, Project Leader : Hayakawa, Kazuichi, Symposium Secretariat: XO kamata, Naoto, Edited by:Kamata, Naoto

Effects of Gypsy Moth Outbreaks on North American Woodpeckers

We examined the effects of the introduced gypsy moth (Lymantria dispar) on seven species of North American woodpeckers by matching spatially explicit data on gypsy moth outbreaks with data on breeding and wintering populations. In general, we detected modest effects during outbreaks: during the breeding season one species, the Red-headed Woodpecker (Melanerpes erythrocephalus), increased over pre-outbreak levels, while during the winter one species, the Yellow-bellied Sapsucker (Sphyrapicus varius), increased and one, the Downy Woodpecker (Picoides pubescens), decreased from pre-outbreak levels. Responses following outbreaks were similarly variable, and in general we were unsuccessful at predicting population responses to outbreaks from a priori knowledge of woodpecker ecology and behavior. We did, however, find evidence that the response of at least half of the species changed over the 34-year period covered by the study: except for the Northern Flicker (Colaptes auratus), whose response to outbreaks during the winter decreased, populations generally responded more positively to outbreaks with time. This temporal response suggests that North American woodpeckers may be taking greater advantage of the resource pulse and/or habitat changes caused by outbreaks of this exotic pest now than previously, so in the future the effects of gypsy moth outbreaks on these species may increase

Emergent Fungal Entomopathogen Does Not Alter Density Dependence in a Viral Competitor

Population cycles in forest Lepidoptera often result from recurring density-dependent epizootics of entomopathogens. While these systems are typically dominated by a single pathogen species, insects are often infected by multiple pathogens, yet little is known how pathogens interact to affect host dynamics. The apparent invasion of northeastern North America by the fungal entomopathogen Entomophaga maimaiga some time prior to 1989 provides a unique opportunity to evaluate such interactions. Prior to the arrival of E. maimaga, the oscillatory dynamics of host gypsy moth, Lymantria dispar, populations were apparently driven by epizootics of a nucleopolyhedrovirus. Subsequent to its emergence, E. maimaiga has caused extensive mortality in host populations, but little is known about how it has altered multigenerational dynamics of the gypsy moth and its virus. Here we compared demographic data collected in gypsy moth populations prior to vs. after E. maimaiga\u27s invasion. We found that the recently invading fungal pathogen virtually always causes greater levels of mortality in hosts than does the virus, but fungal mortality is largely density independent. Moreover, the presence of the fungus has apparently not altered the gypsy moth–virus density-dependent interactions that were shown to drive periodic oscillations in hosts before the arrival of the fungus

Collateral damage: military invasions beget biological invasions

Biological invasions are frequently and closely associated with armed conflict. As a key element of human history, war involves the invasion of (often distant) enemy territories, during which time species can be translocated, intentionally or unintentionally. Large-scale conflicts such as World War I and II, in which thousands of soldiers and supplies (including foodstuffs) were transported within and between continents, resulted in the spread of non-native taxa. However, smaller scale military actions may also involve rapid movements of troops between geographical areas, potentially facilitating the accidental introduction of species into previously unoccupied areas. Furthermore, invasive pests have occasionally been used by armies as weapons to weaken and disrupt opposing forces or nations. The introduction of invasive species during war could be considered relatively minor collateral damage, but many biological invasions in conflict zones have long-lasting effects. Regulation of military practices to minimize or prevent biological invasions through existing international conventions has so far been unsuccessful, necessitating the development of additional measure

European gypsy moth (Lymantria dispar dispar L.) completes development and defoliates exotic radiata pine plantations in Spain

Background Like most pines, radiata pine (Pinus radiata D.Don) is conventionally considered resistant to defoliation by European gypsy moth, i.e. it is only consumed by late larval stages, or when susceptible species are not available or are scarce. The ability of this moth to complete development on this host in field conditions has never been reported. Findings A gypsy moth outbreak in a pure radiata pine plantation was observed in north-western Spain, where this insect is endemic. During the 2 years of outbreak culmination (2012 and 2013), approximately 46 ha of radiata pine were severely defoliated (>75 % of leaf area removed) and no defoliation was evident in nearby stands of susceptible species. Large numbers of egg masses were present on stems of pine trees. Larvae were observed feeding exclusively on radiata pine needles beginning with the first instar and continuing to pupation. Nearly 100 % tree mortality occurred in stands severely defoliated. Conclusions The occurrence of a European gypsy moth outbreak in a pure radiata pine plantation contradicts previous observations that larvae of this species cannot complete development in stands comprised entirely of pines. These results suggest that European strains of the gypsy moth hold great potential for damage to commercial radiata pine plantations where this species is utilised in plantation forestry, such as in New Zealand or AustraliaFunding for this research was provided by the Local Goberment of Cubillos del Sil by the contract “Seguimiento y bases para la gestión de las masas forestales afectadas por defoliación de Lymantria dispar en el municipio de Cubillos del Sil”S

European gypsy moth (Lymantria dispar dispar L.) completes development and defoliates exotic radiata pine plantations in Spain

[EN] Background: Like most pines, radiata pine (Pinus radiata D.Don) is conventionally considered resistant to defoliation by European gypsy moth, i.e. it is only consumed by late larval stages, or when susceptible species are not available or are scarce. The ability of this moth to complete development on this host in field conditions has never been reported. Findings: A gypsy moth outbreak in a pure radiata pine plantation was observed in north-western Spain, where this insect is endemic. During the 2 years of outbreak culmination (2012 and 2013), approximately 46 ha of radiata pine were severely defoliated (>75 % of leaf area removed) and no defoliation was evident in nearby stands of susceptible species. Large numbers of egg masses were present on stems of pine trees. Larvae were observed feeding exclusively on radiata pine needles beginning with the first instar and continuing to pupation. Nearly 100 % tree mortality occurred in stands severely defoliated. Conclusions: The occurrence of a European gypsy moth outbreak in a pure radiata pine plantation contradicts previous observations that larvae of this species cannot complete development in stands comprised entirely of pines. These results suggest that European strains of the gypsy moth hold great potential for damage to commercial radiata pine plantations where this species is utilised in plantation forestry, such as in New Zealand or Australia.SILocal Goberment of Cubillos del Sil

Preliminary Results on Predation of Gypsy Moth Pupac during a Period of Latency in Slovakia

Proceedings : IUFRO Kanazawa 2003 "Forest Insect Population Dynamics and Host Influences"., Scedule:14－19 September 2003, Vemue: Kanazawa Citymonde Hotel, Kanazawa, Japan, Joint metting of IUFRO working groups : 7.01.02 Tree resistance to Insects | 7.03.06 Integrated management of forset defoloating insects | 7.03.07 Population dynamics of forest insects, Sponsored by: IUFRO-J | Ishikawa Prefecture | Kanazawa City | 21st-COE Program of Kanazawa University, Editors: Kamata, Naoto | Liebhold, Nadrew M. | Quiring, Dan T. | Clancy, Karen M