Lymantria Dispar

The abundance of twolined chestnut borer, Agrilus bilineatus (Weber), adults were sampled using sticky panels over a 6-year period in a mixed hardwood forest in West Virginia. Sixteen stands (average size 10.5 ha) were used in the study; eight of these were silviculturally thinned in 1989, the remainder were uncut. During 1990 and 1991, populations of gypsy moth, Lymantria dispar

Se llevó a cabo un análisis del impacto económico y ecológico de las especies exóticas invasoras Euwallaceae sp., Xyleborus glabratus, Cactoblastis cactorum, Agrilus planipennis y Lymantria dispar, en diferentes ecosistemas naturales y productivos de México. Para ello se hizo una investigación netamente documental y se adaptó la metodología para el análisis económico de especies invasoras del Programa Global de Especies Invasoras de la Unión Internacional para la Conservación de la Naturaleza (UICN).
La información documental disponible permitió caracterizar las cinco EEI e identificar sus impactos en diferentes ecosistemas forestales y productivos. Los resultados globales del análisis económico indicaron que en el caso de una afectación muy leve del 1% de las plagas en territorio mexicano, las perdidas o beneficios evitados anuales por reducción de los servicios ecosistémicos, puede ascender a 15.158,66 millones de pesos, mientras que con una tasa del 5%, las pérdidas son del orden de los 86.733,02 millones de pesos, cifras nada despreciables ya que representan el 2,36% y el 15,53% repectivamente del valor de la producción agrícola de México para el año 2018.
Los resultados obtenidos de los Análisis Beneficio-Costo, puede ayudar a convencer a las autoridades competentes para aumentar los recursos materiales, humanos y financieros para ampliar y reforzar los programas de vigilancia epidemiológica de plagas agrícolas y forestales en México; sin embargo, los valores obtenidos en el presente trabajo deben ser interpretados con cautela y usados con la misma consideración en el desarrollo de políticas públicas relacionada con los sistemas de vigilancia fitosanitarios.

A total of 189 nucleopolyhedrovirus (NPV) clones were obtained from the NPV-infected larvae of the common cutworm, Spodoptera litura, collected in Japan. Restriction endonuclease (REN) analysis demonstrated that these 189 S. litura NPV (SpltNPV) clones exhibited 33 distinct REN patterns that represented three distinct NPV types designated as type A, type B, and type C SpltNPVs based on the similarity of overall REN patterns. Comparative examination of REN patterns from these clones in this study with those from NPVs published previously indicated that type A SpltNPV corresponded to Spodoptera littoralis NPV (SlNPV)-D or SlNPV-B, whereas type B SpltNPV corresponded to the NPVs widely identified in S. litura larvae in Japan, China, and the Philippines. The overall REN pattern of type C SpltNPV did not resemble REN patterns from any of those NPVs previously identified in S. litura and S. littoralis and was distinct from the REN patterns of NPVs from Autographa californica, Bombyx mori, Hyphantria cunea, Spodoptera exigua, Lymantria dispar, and Orgyia pseudotsugata, suggesting that type C SpltNPV was a novel NPV pathogenic for S. litura. Comparative characterization with S. litura cultured cells and larvae showed that the biological properties with respect to productivity and virulence differed significantly not only among the types of SpltNPV but also among the variants within a SpltNPV type, demonstrating that SpltNPV-C3, a clone from type C SpltNPV, caused rapid mortality of S. litura larvae compared with those clones of type A or type B SpltNPV. These results indicate that the natural heterogeneity of baculoviruses can be exploited to develop NPV strains suitable for the control of S. litura and suggest that the novel SpltNPV-C3 isolated in this study has high potential to be developed as an effective pest control agent for S. litura.

The aberrant replication of the Autographa californica multiple-enveloped nuclear polyhedrosis virus (AcMNPV) in the Lymantria dispar cell line IPLB-Ld652Y was used as a model system for the investigation of factors regulating baculovirus host specificity. A previous study of this system indicates that viral gene expression in infected cells is extremely attenuated and subsequently all cellular and viral protein synthesis is inhibited. In the present study, infection of IPLB-Ld652Y cells with AcMNPV photochemically inactivated in situ resulted in a rapid reduction in cell mitotic indices and cell growth, as well as inducing a series of distinct morphological changes in these cells. At the molecular level, infection with inactivated virus, followed by pulse labelling with [3H]thymidine, resulted in a rapid [0 to 2 h post-infection (p.i.)] and permanent inhibition of host cellular DNA synthesis. Assays of cellular DNA polymerases in isolated IPLB-Ld652Y nuclei confirmed the reduction in cellular DNA synthesis observed in intact cells and indicated an initial (0 to 2 h p.i.) reduction in the activity of aphidicolin-sensitive DNA polymerases. Activity of all cellular DNA polymerases was inhibited at later times p.i. Host cell protein synthesis was completely inhibited after 48 h p.i. Treatment of inactivated virus and virus-infected cells with various chemical and physical factors (i.e. pH and temperature) or lysosomotropic agents revealed that virus entry into cells and fusion of endocytic vesicles (containing virus) with lysosomes were essential for suppression of cellular macromolecular synthesis. The possible involvement of structural components of the AcMNPV virion in these effects is discussed.

Gypsy moth (Lymantria dispar L.) outbreaks affect stand dynamics and successional patterns in pine–oak woodlands of North America's Atlantic coastal plain. Species-poor overstories are dominated by pitch pine (Pinus rigida), black oak (Quercus velutina) and white oak (Quercus alba). Both oaks are preferred food for gypsy moth, and white oak is the dominant late-successional species. We documented, over a 21-year period, the effects of gypsy moth defoliation on forest stand dynamics at Cape Cod National Seashore, Massachusetts. Our goal was to better understand the influence of gypsy moth defoliation on temporal changes in stand composition. Tree species abundance and frequency were measured in 16 stands with varying abundances of pitch pine and oak. Regression of 2-dimesional rates of change calculated from principal components analysis showed that gypsy moth significantly influenced stand dynamics and successional patterns between 1981 and 1992/1993. Defoliation was virtually absent in the 1990s, and analysis of 1992/1993–2002 rates of change showed topographic slope to be the most important factor influencing stand dynamics during this time. For the period 1981–2002 rates of change analysis failed to identify either factor as influencing changes in stand dynamics. We conclude that the 1980s defoliation events had a transitory effect on upland forest composition, but that there exists the potential for significant long-term impact due to recurrent defoliation episodes. Stand composition should be monitored at intervals which roughly correspond to the time it takes for stands to recover to disturbance events, in the case of those we sampled, approximately 10 years.

This paper presents a novel methodology for multi-scale and multi-type spatial data integration in support of insect pest risk/vulnerability assessment in the contiguous United States. Probability of gypsy moth (Lymantria dispar L.) establishment is used as a case study. A neural network facilitates the integration of variables representing dynamic anthropogenic interaction and ecological characteristics. Neural network model (back-propagation network [BPN])

Gypsy moth (Lymantria dispar) populations were low this past season across the state, as were populations of eastern tent cater-pillar (Malacosoma americanum) and fall webworm (Hyphantria cunea). However, localized damaging infestations of yellow-necked caterpillar (Datana ministra) and bagworm (Thyridopteryx ephemeraeformis) were observed throughout the state. Mimosa webworm (Homadaula anisocentra) caused noticeable browning of honey-locusts in northeastern Ohio. Larch casebearer (Coleophora laricella) was com-mon on its namesake in the southwestern and northeastern areas of the state.

Considering the vast Eurasian distribution of gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), the many subspecies, and their presence in different lymantriid communities, we tested the hypothesis that L. dispar populations in eastern Asia employ one or more pheromone components in addition to the previously known single component pheromone (7R,8S)-cis-7,8-epoxy-2-methyloctadecane [= (+)-disparlure]. Coupled gas chromatographic–electroantennographic detection (GC–EAD) analyses of pheromone gland extracts of female L. dispar sensu lato (including both AGM and NAGM) on four GC columns (DB-5, DB-23, DB-210, and SP-1000) revealed a new trace component that eluted just before (DB-5; DB-210) or after (DB-23, SP-1000) disparlure, and elicited strong antennal responses. Isolation of this compound by high-performance liquid chromatography and hydrogenation produced disparlure, suggesting that the new component had the molecular skeleton of disparlure, with one or more double bonds. Of all possible monounsaturated cis-7,8-epoxy-2-methyloctadecenes, only cis-7,8-epoxy-2-methyloctadec-17-ene co-chro- matographed with the insect-produced compound on all GC columns and elicited comparable antennal responses. In field experiments in Honshu (Japan) with enantioselectively synthesized compounds, (7R,8S)-cis-7,8-epoxy-2- methyloctadec-17-ene (7R8S-epo-2me-17-ene-18Hy) was weakly attractive to male L. dispar, but was less effective as a trap bait than (+)-disparlure, and failed to enhance attractiveness of (+)-disparlure when tested in blends. The antipode, (7S,8R)-cis-7,8-epoxy-2-methyloctadec-17-ene, was not attractive, and when added to (+)-disparlure and/or 7R8S-epo-2me-17-ene-18Hy reduced attractiveness. Thus, the biological role of 7R8S-epo-2me-17-ene-18Hy remains unclear. It may enhance pheromone attractiveness or specificity in other L. dispar populations within their vast Eurasian distribution.

The ecdysteroid UDP-glycosyltransferase (egt) gene of Epinotia aporema granulovirus (EpapGV) was cloned sequenced and its biological activity was assessed. It encodes a protein of 446 amino acids. Direct evidence that the cloned gene encodes an active EGT protein was obtained by transient expression assays in insect cells. The upstream untranslated region of the egt gene exhibits several consensus early promoter elements. Accordingly, the gene is expressed early upon infection of Epinotia aporema larvae and the EGT activity remains high until later times post infection. Sequence analyses indicate the presence of clusters of amino acid residues conserved among all the baculoviral EGTs, although their relation with proper protein folding, ligand binding and catalytic activity remain to be assessed. Phylogenetic trees consistently cluster the granulovirus EGTs separating them clearly from the nucleopolyhedroviruses.

Increasing atmospheric concentrations of ozone and CO2 affect many aspects of tree physiology. However, their effects on tree resistance to insects have received relatively little attention. The objectives of this study were to test the effects of elevated CO2 and ozone on the resistance of three quaking aspen (Populus tremuloides) clones (216, 259, and 271) to first and fourth instars of four Lepidoptera species: gypsy moth (Lymantria dispar), forest tent caterpillar (Malacosoma disstria), large aspen tortrix (Choristoneura confictana), and whitemarked tussock moth (Orgyia leucostigma). Larval survival, growth rates, and nutritional indices were quantified. There were no treatment effects on larval survival. Elevated CO2 decreased the growth rates of both instars of all species, except that of first instar forest tent caterpillar on aspen clone 216, which was increased. Elevated ozone increased the growth of first and fourth instars of all insect species tested. The treatment effec...