Orgyia leucostigma (J.E. Smith), whitemarked tussock moth (Lepidoptera: Lymantriidae).

AbstractIn Nova Scotia, the whitemarked tussock moth, Orgyia leucostigma Fitch, periodically erupts in outbreaks that typically last 3–5 years. Population changes during a recent outbreak were monitored by means of aerial defoliation surveys and fall egg-mass surveys that were conducted between 1997 and 2001. Severe defoliation was first recorded on approximately 250 ha in 1996. The defoliated area increased rapidly to hundreds of thousands hectares in 1998, after which it sharply declined to about 4700 ha in 2000 and 0 ha in 2001. The total infested area [>0.01 egg masses per three branches of Abies balsamea L. (Pinaceae)] decreased from about 1.4 million ha in 1997 to about 13 500 ha in 2001. Between 1996 and 2001, the infestation involved a cumulative total of 2.4 million ha, covering most of the province. The collapse of larval populations during 1998 was associated with widespread prevalence of a singly embedded nucleopolyhedrovirus (NPV) and Entomophaga aulicae (Reichardt in Bail) Humber (Zygomycetes: Entomophthorales). Sampling of larval populations in late July and August 1998 revealed a widespread and virtually sympatric occurrence of those pathogens in areas that were under defoliation pressure, with infection levels by each pathogen exceeding 75% in many sample sites. Pathogen impacts on larval survival were studied in 1999 in a persisting pocket of severe infestation in Hants County. Larvae were collected every 3 d from balsam fir branch samples between 17 June and 21 July and reared to determine cause of death. The two pathogens together accounted for at least 50% of cohort mortality, calculated as marginal mortality rates according to Royama (2001). Although cohort mortality due to disease on balsam fir was significantly correlated with between-generation reduction in mean egg-mass density, overall pathogen-induced mortality was not high enough to drive the populations into an endemic state, and a moderate infestation persisted into 2000.

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Larval diet prior to and following virus ingestion influences the efficacy of two nucleopolyhedroviruses in whitemarked tussock moth (Orgyia leucostigma) caterpillars

The Canadian Entomologist ◽

10.4039/tce.2012.2 ◽

2012 ◽

Vol 144 (3) ◽

pp. 447-457 ◽

Cited By ~ 3

Author(s):

Garrett Brodersen ◽

Rob Johns ◽

Renée Lapointe ◽

David Thumbi ◽

Graham Thurston ◽

...

Keyword(s):

Artificial Diet ◽

Viral Infections ◽

Abies Balsamea ◽

Field Studies ◽

Balsam Fir ◽

Betula Papyrifera ◽

White Birch ◽

Tussock Moth ◽

Orgyia Leucostigma ◽

Whitemarked Tussock Moth

AbstractFood quality can influence the performance of immature insects and their interactions with pathogens, such as viruses. In manipulative field studies, virus-free caterpillars of the whitemarked tussock moth (WMTM) (Orgyia leucostigma (Smith)) had higher survival, more female-biased sex ratios, and were larger when feeding on white birch (Betula papyrifera Marshall) versus balsam fir (Abies balsamea (Linnaeus) Miller) or red spruce (Picea rubens Sargent). Subsequent laboratory studies with two nucleopolyhedroviruses, derived from WMTMs and Douglas-fir tussock moths, indicated that caterpillars fed high quality food (i.e., artificial diet) prior to infection had less mortality associated with virus infection than those feeding on lower quality foliage (i.e., birch). In field studies, caterpillars fed birch following infection had significantly lower mortality than those feeding on relatively lower quality foliage (i.e., balsam fir). We postulate that higher nutritional quality in artificial diet relative to birch (previrus-ingestion nutrition) and in birch relative to balsam fir foliage (postvirus-ingestion nutrition) has a positive effect on the ability of tussock moth caterpillars to resist or recover from viral infections, although the specific mechanisms responsible for observed resistance remain unclear.

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Copulation releaser pheromone in body scales of female whitemarked tussock moth,Orgyia leucostigma (Lepidoptera: Lymantriidae): Identification and behavioral role

Journal of Chemical Ecology ◽

10.1007/bf01025894 ◽

1987 ◽

Vol 13 (2) ◽

pp. 345-356 ◽

Cited By ~ 23

Author(s):

G. G. Grant ◽

D. Frech ◽

L. MacDonald ◽

K. N. Slessor ◽

G. G. S. King

Keyword(s):

Tussock Moth ◽

Orgyia Leucostigma ◽

Whitemarked Tussock Moth ◽

Releaser Pheromone

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DNA hybridization assay for detection of nucleopolyhedrovirus in whitemarked tussock moth (Orgyia leucostigma) larvae

Pest Management Science ◽

10.1002/1526-4998(200101)57:1<66::aid-ps262>3.0.co;2-6 ◽

2001 ◽

Vol 57 (1) ◽

pp. 66-71 ◽

Cited By ~ 2

Author(s):

Peter M Ebling ◽

Penelope A Smith ◽

Kees van Frankenhuyzen

Keyword(s):

Dna Hybridization ◽

Hybridization Assay ◽

Tussock Moth ◽

Orgyia Leucostigma ◽

Whitemarked Tussock Moth

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Obligatory multiparasitism in the tussock moth,Orgyia leucostigma

Parasitology ◽

10.1017/s0031182000048964 ◽

1985 ◽

Vol 90 (1) ◽

pp. 1-10 ◽

Cited By ~ 40

Author(s):

D. Guzo ◽

D. B. Stoltz

Keyword(s):

Immune Response ◽

Viral Genome ◽

Cross Linking ◽

Viral Dna ◽

Permissive Host ◽

Tussock Moth ◽

Complete Development ◽

Orgyia Leucostigma ◽

Cotesia Melanoscela

Orgyia leucostigmahaemocytes were able to encapsulate and destroy eggs ofHyposoterspecies, thereby preventing successful parasitism. When host larvae had previously been parasitized byCotesia melanoscela, however, this response was not observed, and 3 differentHyposoterspecies could be reared to maturity in the normally non-permissive host. Appropriate injection experiments established thatC. melanoscelavirus and venom were both required in order for successful parasitism byHyposoterto occur. Covalent cross-linking ofC. melanoscelaviral DNA led to an immune response againstHyposoterlarvae, but not eggs, suggesting that an active viral genome may be required for complete development ofHyposoterspecies in tussock moth larvae.

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