BioControl (2004) 49, 1-19
Stefan Kuske, Dirk Babendreier, Peter Edwards, Ted C.J. Turlings and Franz Bigler (2004)
Parasitism of non-target lepidoptera by mass released Trichogramma brassicae and its implication for the larval parasitoid Lydella thompsoni
BioControl 49 (1), 1-19
Abstract: The release of high numbers of the egg parasitoid Trichogramma brassicae Bezd. (Hym. Trichogrammatidae) to control the European corn borer (ECB), Ostrinia nubilalis Hb. (Lep.: Crambidae) in maize has raised concerns about potential negative effects on native natural enemies. The native larval parasitoid Lydella thompsoni Herting (Dipt.: Tachinidae) is the most frequent and important ECB parasitoid in southern Switzerland and can achieve high parasitism rates. Its first generation emerges too early to find ECB larvae and must rely on alternative hosts living in natural habitats close to maize fields. Inundative releases of T. brassicae coincide with the oviposition period of the alternative hosts of the tachinid. T. brassicae moving out of release fields may attack and diminish the population of these hosts, creating a bottleneck situation for L. thompsoni in the subsequent spring. Laboratory host specificity tests showed that the tachinid's two most abundant spring hosts Archanara geminipuncta Haworth (1809) (Lep.: Noctuidae) and Chilo phragmitellus Hübner (1805) (Lep.: Crambidae) are successfully parasitised by T. brassicae females in no-choice situations. Our extensive field surveys, however, showed that the two tested spring hosts escape parasitism since their eggs are well hidden or not attractive. Negative effects of inundative releases of T. brassicae on the native tachinid fly L. thompsoni, such as population density reduction, displacement, or local extinction, are very unlikely.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Stefan Kuske, Ted C.J. Turlings, Dirk Babendreier
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Ostrinia nubilalis | Maize/corn (Zea mays) | Switzerland | ||
| Trichogramma brassicae (parasitoid) | Ostrinia nubilalis | Maize/corn (Zea mays) | Switzerland | |
| Lydella thompsoni (parasitoid) | Ostrinia nubilalis | Maize/corn (Zea mays) | Switzerland |
