The Host Range ofEccritotarsus catarinensis(Heteroptera: Miridae), a Potential Agent for the Biological Control of Waterhyacinth (Eichhornia crassipes)

Abstract

Abstract The host range of Eccritotarsus catarinensis was determined using 33 plant species to assess the risk of using this insect, a native of South America, for the classical biological control of waterhyacinth ( Eichhornia crassipes ) in Australia and Papua New Guinea. The results, in conjunction with the results of Hill et al. (1999) who tested 67 species (mostly South African), strongly suggest that E. catarinensis is restricted to the Pontederiaceae, a family of aquatic plants. All five species of Pontederiaceae in the Australian testing, E. crassipes, Pontederia cordata, Monochoria vaginalis, M. cyanea, and M. australasica, were suitable for insect development. Colonies persisted for at least four generations on E. crassipes, P. cordata, and M. vaginalis. Two-way choice and multiple-choice preference trials were conducted and discussed. E. catarinensis did not exhibit a clear preference for waterhyacinth over other Pontederiaceae in these trials. Most oviposition occurred into the upper surface of the lamina during laboratory testing despite observations that the underside was preferred in the field. Although not considered suitable for release in Australia, this insect may be useful in other countries where more serious waterhyacinth problems occur and where M. vaginalis is a serious weed, such as in Southeast Asia.