Journal of Insect Science (2004) 4 (28), p. 12 (Schafellner et al.)
C. Schafellner, R.C. Marktl and A. Schopf (2004)
Parasitism by Glyptapanteles liparidis (Hym., Braconidae) alters the juvenile hormone metabolism of its host larva, Lymantria dispar
Journal of Insect Science 4 (28), 12-12
Abstracts from Eighth International Conference on the Juvenile Hormones
Abstract: As shown earlier, parasitization by the larval parasitoid G. liparidis induces a dramatic increase in the hemolymph juvenile hormone (JH) titer of its host larva, especially in the JH III homologue, while the activity of the JH degrading enzyme (JHE) is reduced compared to unparasitized controls. Here we investigated the role of the parasitoids and associated factors in JH synthesis and degradation. GC-MS analysis confirmed that the rising hemolymph JH titers coincided with the parasitoids' molt into 2nd instars. Peak values were observed prior to parasitoid emergence from the host larva and titers dropped to negligible levels shortly afterwards. Whole body extracts from 2nd instar parasitoids yielded JH III and trace amounts of JH II. When the host's corpora allata were separated by neck ligation, levels of JH III were elevated in the hemolymph of the posterior section, which contained the parasitoids, but no JH II was found. When parasitoids were kept in in vitro culture, they produced and released only JH III. The parasitoids, on the other hand, had little influence on JH degradation. JHE suppression was induced solely by the polydnavirus/venom complex which is injected into the host larva at oviposition. Host JHE gene expression was not affected by parasitization.
Database assignments for author(s): Robert C. Marktl, Axel Schopf
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Lymantria dispar | ||||
| Glyptapanteles liparidis (parasitoid) | Lymantria dispar |
