Journal of Applied Entomology - Zeitschrift für angewandte Entomologie (1997) 121, 195-203

A. Schopf and G. Hoch (1997)
Zur Bionomie und Bedeutung von Glytapanteles liparidis (Hym., Braconidae) als Regulator von Lymantria dispar (Lep., Lymantriidae) in Gebieten mit unterschiedlichen Populationsdichten
[Bionomics and the significance of Glyptapanteles liparidis (Hym., Braconidae) as a regulator of Lymantria dispar (Lep., Lymantriidae) in different host population densities]
Journal of Applied Entomology - Zeitschrift für angewandte Entomologie 121 (4), 195-203
Abstract: At three localities with initially high, intermediate, and low density populations of gypsy moth, stage specific parasitism by the gregarious braconid, G. liparidis was studied throughout the years 1993 to 1995. Emergence of the parasitoid larvae from the collected gypsy moth larvae started in the laboratory at 20°C in the 19th and 20th'week, that was two weeks earlier than in the field. Parasitoid larvae mainly emerged from 4th instar hosts 1993. Delayed development of gypsy moth larvae in field, caused by low temperatures during spring in the years 1994 and 1995 and partly by artificial augmenting at the innocuous site, increased parasitization rate by the braconid wasp in total and the number of 3rd instar hosts from which parasitoids emerged. A bimodal mode of emergence was found in 1994 when parasitoid larvae left their 3rd or 4th instar hosts between the 19th and 23rd week and the 4th, 5th, and one 6th instar hosts between the 25th to 28th week. Generally, more parasitoids emerged from 4th instar hosts than from older host instars. Highest parasitism at a rate of 48% was found in gypsy moth larvae of the 3rd and 4th stadium at the low density site, where the gypsy moth population was artificially augmented. Overall, we found indications of an inverse relationship between host density, estimated by the number of egg masses, and the rate of parasitism by G. liparidis, but a density dependent relationship between egg masses and the number of cocoon clusters of the parasitoids in low and intermediate gypsy moth populations. Thus, the parasitized species is believed to be a specialist of low host population densities. The rate of parasitized host larvae, however, was not correlated with the number of cocoon clusters of the emerged parasitoid larvae counted in autumn. Hyperparasitism of the parasitoid cocoons was between 6 and 15% during outbreak conditions of gypsy moth.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: German)
Link to article at publishers website
Database assignments for author(s): Axel Schopf, Gernot Hoch

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
population dynamics/epizootiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Lymantria dispar
Glyptapanteles liparidis (parasitoid)	Lymantria dispar