NATURAL MORTALITY OF THE GYPSY MOTH ALONG A GRADIENT OF INFESTATION

1999 ◽  
Vol 131 (4) ◽  
pp. 507-519 ◽  
Author(s):  
V.G. Nealis ◽  
P.M. Roden ◽  
D.A. Ortiz
Keyword(s):  
Snow Cover ◽  
Relative Abundance ◽  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Rank Order ◽  
Ground Level ◽  
Common Species ◽  
Natural Mortality ◽  
Single Source ◽  
Entomophaga Maimaiga

AbstractNatural mortality of gypsy moth [Lymantria dispar (L.) (Lepidoptera: Lymantriidae)] eggs, larvae, and pupae was examined at several locations along a gradient of infestation in Ontario, Canada. Most mortality of eggs was the result of exposure to winter weather. This mortality was mitigated in egg masses located near ground level where they benefited from snow cover. At least six species of parasitoids were found attacking gypsy moth larvae and pupae. The most common species were present in the same rank order of abundance at all sites. Identified pathogens were also present in most sites but their relative abundance varied greatly. The mycopathogen Entomophaga maimaiga Humber, Shimazu & Soper (Zygomycetes: Entomophthorales) was found at all sites and usually was responsible for the highest levels of observed, single-source mortality at the site.

PREDATION BY CALOSOMA SYCOPHANTA L. (COLEOPTERA: CARABIDAE): EVIDENCE FOR A LARGE IMPACT ON GYPSY MOTH, LYMANTRIA DISPAR L. (LEPIDOPTERA: LYMANTRIIDAE), PUPAE

1985 ◽  
Vol 117 (9) ◽  
pp. 1117-1126 ◽  
Author(s):  
Ronald M. Weseloh
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Ground Level ◽  
Mortality Factor ◽  
Substantial Impact ◽  
Entire Study ◽  
Dispersal Potential ◽  
Capture Recapture ◽  
The Impact ◽  
Entire Study Area

AbstractThe impact of predation by Calosoma sycophanta L. on an increasing prey population was assessed by recapturing marked adult beetles, periodically observing tagged gypsy moth pupae, and examining gypsy moth pupal remains in different microhabitats. Adult beetles dispersed in random directions but many tended to remain near the trap at which they were originally caught, suggesting a low dispersal potential. About 75% of the adult beetles present in the plot on one day were still present the next day. Capture–recapture estimates suggested that there were at most about 250 male beetles and half as many females/ha in the plot. Calosoma larvae destroyed 70% of tagged gypsy moth pupae under burlap bands on tree trunks near ground level, which was much more than any other mortality factor. Although this percentage was the same when mortality was assessed by looking at pupal remains within 5 m of the ground on tree trunks, pupae higher in trees and on leaves were not attacked as frequently. On average, about 40% of the pupae present in the entire study area were destroyed by Calosoma larvae. Each female beetle in the site would have had to produce about 30 progeny to have this effect. These data suggest that a relatively low number of adult beetles can have a substantial impact on gypsy moth populations.

Isolation and characterization of Entomophaga maimaiga sp. nov., a fungal pathogen of gypsy moth, Lymantria dispar, from Japan

1988 ◽  
Vol 51 (3) ◽  
pp. 229-241 ◽  
Author(s):  
Richard S. Soper ◽  
Mitsuaki Shimazu ◽  
Richard A. Humber ◽  
Mark E. Ramos ◽  
Ann E. Hajek
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Fungal Pathogen ◽  
Isolation And Characterization ◽  
Entomophaga Maimaiga

Quantitative Analysis of a Pathogen-Induced Premature Collapse of a “Leading Edge” Gypsy Moth (Lepidoptera: Lymantriidae) Population in Virginia

1999 ◽  
Vol 34 (1) ◽  
pp. 84-100 ◽  
Author(s):  
R. E. Webb ◽  
G. B. White ◽  
K. W. Thorpe ◽  
S. E. Talley
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Nuclear Polyhedrosis Virus ◽  
Leading Edge ◽  
Late Season ◽  
Early Appearance ◽  
Entomophaga Maimaiga ◽  
Resting Spores ◽  
Nuclear Polyhedrosis ◽  
Second Wave

The population dynamics of a “leading edge” (= at the edge of the expanding gypsy moth invasion) gypsy moth, Lymantria dispar (L.), population was monitored for 3 years (1995–97), with emphasis on the interactions of the gypsy moth nuclear polyhedrosis virus (LdNPV) and the fungus Entomophaga maimaiga Humber, Shimazu, & Soper. Gypsy moth populations in the woodlots varied from very sparse to high (potentially defoliating) levels. LdNPV was strongly density dependent, being confirmed only from the higher populated woodlots. In contrast, the fungus was similarly active in both sparse and highly-populated woodlots. In 1995, the fungal epizootic developed late in the season, with most larvae succumbing during stadia 5–6 and producing mainly resting spores (azygospores). Estimated mortality due to fungus averaged 68% in high-density plots and 85% in low-density plots. LdNPV mortality occurred in a two-wave epizootic, although second-wave LdNPV mortality was undoubtedly reduced because of the reduction of late-season larvae due to fungus activity. Estimated mortality due to LdNPV averaged 14% in highly-populated plots and 1% in low-population plots. In 1996, high levels of fungal-induced mortality occurred earlier in the gypsy moth season than in the previous year. Most gypsy moth larvae in 1996 died in a mid-season wave of fungal-induced mortality, with necropsied cadavers containing only conidia. This resulted in relatively few larvae surviving to late instars. At this time, a second wave of fungus-induced mortality occurred, with over half of the necropsied cadavers containing resting spores. The depletion of the gypsy moth populations by the fungus in 1995 resulted in a greatly reduced first wave of LdNPV in all plots in 1996, and perhaps due to the early appearance of the fungus in 1996, LdNPV was nearly absent from late-season larvae collected from all plots. In 1997, gypsy moth populations were uniformly low, and no dead larvae were found in any of the plots.

Interactions between the introduced fungal pathogen Entomophaga maimaiga and indigenous tachinid parasitoids of gypsy moth Lymantria dispar in Bulgaria

2012 ◽  
Vol 41 (2) ◽  
pp. 125-131 ◽  
Author(s):  
Georgi Georgiev ◽  
Zdravko Hubenov ◽  
Margarita Georgieva ◽  
Plamen Mirchev ◽  
Maria Matova ◽  
...  
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Fungal Pathogen ◽  
Entomophaga Maimaiga

scholarly journals Gypsy moth, Lymantria dispar (L.), and its natural enemies in the forests of Central Serbia

2012 ◽  
pp. 133-147
Author(s):  
Mara Tabaković-Tošić
Keyword(s):  
Gypsy Moth ◽  
Natural Enemies ◽  
Lymantria Dispar ◽  
Dominant Role ◽  
Larval Instar ◽  
Entomophaga Maimaiga ◽  
Nucleopolyhedrosis Virus

In central Serbia, a total of 88 species which are natural enemies of the gypsy moth, i.e. 23 predators, 49 parasitoid insects and 10 saprophagous insects, and 6 pathogens, has been reported. The most abundant of them are the insects which attack the gypsy moth in the larval instar (41 species). Regarding the number of the species, the representatives of the Hymenoptera (14 species from Ichneumonidae family and 11 species from Braconidae family) and Diptera orders (12 species from Tachinidae family and 8 species from Sarcophagidae family) are most frequent. Regarding the predators of the gypsy moth, Carabidae family, from Coleoptera order, is most frequent. In addition, at some sites Lymantria dispar nucleopolyhedrosis virus and Entomophaga maimaiga had the dominant role in the reduction of the gypsy moth density.

Types of spores produced by Entomophaga maimaiga infecting the gypsy moth Lymantria dispar

1996 ◽  
Vol 74 (5) ◽  
pp. 708-715 ◽  
Author(s):  
Ann E. Hajek ◽  
Mitsuaki Shimazu
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Fungal Pathogen ◽  
Fungal Spores ◽  
Serial Passage ◽  
Molting Cycle ◽  
Resting Spore ◽  
Entomophaga Maimaiga ◽  
Resting Spores ◽  
Study Support

We investigated the association of environmental factors (temperature, photoperiod, host molting status) and fungal factors (isolate, dose, strain attenuation) with the production of conidia versus resting spores by the entomopathogenic fungus Entomophaga maimaiga infecting the larvae of the gypsy moth Lymantria dispar. Fungal spores produced from individual cadavers of larvae killed by E. maimaiga can include conidia discharged from the cadaver surface, resting spores (azygospores) within the cadaver, or both spore types. The single factor having the greatest impact on the type of spore produced was host age; second instars virtually never contained resting spores, independent of temperature, while fifth instar cadavers contained resting spores more frequently at higher temperatures. However, there was increased conidiation at lower temperatures. Photoperiod was the only factor studied that did not significantly influence the type of spore produced. Resting spore production was negatively associated with the molting cycle; cadavers of those larvae that molted or exhibited premolt characteristics during the period between infection and death contained fewer resting spores. Increased fungal dose yielded more resting spores, as did extensive serial passage, which simultaneously caused a decrease in conidiation. Fungal isolates varied in the types of spores produced, with fewer cadavers of larvae killed by the least virulent isolate discharging conidia. Results from this study support the hypothesis that both the condition of the fungal pathogen as well as the environment surrounding it contribute to the types of spores produced. Keywords: fungal sporulation, resting spores, azygospores, Entomophthorales, Entomophaga maimaiga, biological control.

Sign in / Sign up

Export Citation Format

Share Document