Ecological Effects of an Insect Introduced for the Biological Control of Weeds

See allHide authors and affiliations

Science  22 Aug 1997:
Vol. 277, Issue 5329, pp. 1088-1090
DOI: 10.1126/science.277.5329.1088

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution


Few data exist on the environmental risks of biological control. The weevil Rhinocyllus conicus Froeh., introduced to control exotic thistles, has exhibited an increase in host range as well as continuing geographic expansion. Between 1992 and 1996, the frequency of weevil damage to native thistles consistently increased, reaching 16 to 77 percent of flowerheads per plant. Weevils significantly reduced the seed production of native thistle flowerheads. The density of native tephritid flies was significantly lower at high weevil density. Such ecological effects need to be better addressed in future evaluation and regulation of potential biological control agents.

  • * To whom correspondence should be addressed. E-mail: slouda{at}

View Full Text

Stay Connected to Science