Overseas Surveys (1981-1983) for Insects to Control Hydrilla.
Abstract
Three extended collecting trips to Asia and Australia where hydrilla is considered to be native were made to catalog the natural enemies of this plant. These three surveys yielded 180 collections containing over 45 insect species which attack hydrilla. All 45 of these insects are either weevils, ephydrid flies, or aquatic moths, groups which are known to be herbivorous and host-specific. Insects which only occasionally damage hydrilla, such as caddisfly and midge larvae, are not included in the list. More intensive surveying would also multiply this number of candidate species. Compared to the handful of insect species found attacking hydrilla in the United States during and intensive multiyear survey, it is apparent that hydrilla in the United States is depauperate in natural enemies. This helps to account for native competitors are absent, introduced biological control insects would have high chance of becoming established in the United States. The control of hydrilla in the United States by introduced exotic insects now appears more probable, and the hydrilla biological control project should be intensified. Achieving a level of hydrilla control comparable to that observed overseas will probably require the introduction of a complex of insects (including leaf-miners, defoiliators, stem-borers, and tuber feeders).
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1985
- Accession Number
- ADA165419
Entities
People
- Joseph K. Balciunas