Document: SUS-3-69-50

A new technique evaluating host suitability in Ophraella communa, an exotic natural enemy of hogweed.

KAWABE, S.*

National Institute of Agro-Environmental Sciences, Tukuba 305-8604 JAPAN ¹

Abstract:
The evaluation of ecological impacts of exotic natural enemies on agro-ecosystems is a challenging task because they often attack alternative hosts of economic or ecological importance. Ambrosia artemisiifolia, a noxious cosmopolitan weed, is now a pervasive pest in Japan. This weed has a natural enemy, Ophraella communa, which has recently invaded Japan from North America and rapidly expanding its habitats. However, this natural enemy also attacks ornamental or edible composites such as Helianthus annuus, H. argophyllus and H. tuberosus, and other weeds such as Xanthium canadense and A. trifida. To study its host range, I used Electronic Measurement on Insect Feeding Behavior (EMF), which has originally been designed to analyze the feeding behavior of insects with sucking mouth parts and is now a widely-used technique because it can identify the specificity of host plant tissues that are fed by many sucking insects. I applied EMF by using our improved computerized device to O. communa that has chewing mouth parts and found it possible to measure the interval, frequency, speed, duration of feeding and time before feeding. Our EMF device was also found effective in determining of O. communa actively feeds on alternative hosts, thus testing host suitability. Therefore, EMF is useful to examine the potential of insect natural enemies with chewing mouth parts in controlling troublesome weeds. Evaluation of ecological impact of invasive/introduced organisms on the agro-ecosystems is very important for Japanese agriculture. Japanese archipelago extends from south to north with various landscapes and climates, thus has a unique and diverse biota, and conservation of this rich biodiversity is very important for sustainable agriculture. The technique presented here should be useful for the basic research on reasonable use/control of invasive/introduced insects.

Keywords: Sutainable agricuture, invasive/introduced insects, negative impacts on the ecosystem

This abstract is being presented at: 11:30 AM in session:
Oral Session #4: Herbivore Responses to Plants.