Entomologia Experimentalis et Applicata (1999) 91, 155-161

L.R. Baggen, G.M. Gurr and A. Meats (1999)
Flowers in tri-trophic systems: mechanisms allowing selective exploitation by insect natural enemies for conservation biological control
Entomologia Experimentalis et Applicata 91 (1), 155-161
Abstract: Many insects have coevolved with certain angiosperm taxa to act as pollinators. However, the nectar and pollen from such flowers is also widely fed upon by other insects, including entomophagous species. Conservation biological control seeks to maximise the impact of these natural enemies on crop pests by enhancing availability of nectar and pollen-rich plants in agroecosystems. A risk with this approach is that pests may also benefit from the food resource. We show that the flowers of some plants (viz., buckwheat, Fagopyron esculentum Moench and dill, Anethum graveolens L.), and the extrafloral nectaries of faba bean (Vicia faba L.) benefit both Copidosoma koehleri Blanchard (Hymenoptera: Encyrtidae) and its host, the potato pest, Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae). In contrast, phacelia (Phacelia tanacetifolia Benth) and nasturtium (Tropaeoleum majus L.) benefited only the parasitoid. When adult moths of P. operculella were caged with flowers of phacelia or nasturtium, longevity of males and females, egg laying life, fecundity, average oviposition rate, and number of eggs in ovaries at death were no greater than in the control treatment with access to shoots without flowers plus water. All the foregoing measures were increased compared to the control when the moths were allowed access to dill, buckwheat or faba bean extrafloral nectaries. Such 'selectivity' has the potential to make the use of floral resources in conservation biological control more strategic. We present morphometric and observational evidence to illustrate how such mechanisms may operate.
(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): Alan Meats, Geoff M. Gurr

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
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.
	Phthorimaea operculella	Broad/faba bean (Vicia faba)
	Phthorimaea operculella	Dill (Anethum graveolens)
Copidosoma koehleri (parasitoid)	Phthorimaea operculella	Broad/faba bean (Vicia faba)
Copidosoma koehleri (parasitoid)	Phthorimaea operculella	Dill (Anethum graveolens)