ARS | Publication request: Susceptibility of adult nut curculio, Curculio hicoriae (Coleopter: Curculionidae) to entomopathogenic nematodes under laboratory conditions

Submitted to: Journal of Entomological Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 25, 2012
Publication Date: N/A

Interpretive Summary: A weevil pest called the nut curculio can cause serious damage to pecans in the southeastern United States. This insect may be controlled with chemical insecticides. However, chemical insecticides can destroy beneficial natural enemies (such as lady beetles) and harm the environment. Therefore, research toward developing environmentally friendly methods to control nut curculio is warranted. Our objective was to determine the potential of entomopathogenic nematodes to control nut curculio. Entomopathogenic nematodes are tiny round worms. Unlike some other kinds of nematodes, the entomopathogenic nematodes only attack insects; they do not harm plants, mammals or the environment. We tested three species of entomopathogenic nematodes for the ability to kill adult nut curculio in the laboratory. We discovered that two of the nematode species (called Steinernema carpocapsae and Steinernema riobrave) are capable of killing nut curculio, whereas the third species (Heterorhabditis indica) did not kill nut curculio. In future research the two nematode species that were successful in the laboratory will be tested further in the field for their ability to act as natural control agents of nut curculio.

Technical Abstract: The nut curculio, Curculio hicoriae, can cause serious damage to pecans in the southeastern United States. Although the pest can be controlled with chemical insecticides, research toward developing environmentally friendly methods to control C. hicoriae is desirable. Our objective was to determine the potential of entomopathogenic nematodes to control C. hicoriae. Three species of entomopathogenic nematodes were tested for virulence and pathogenicity to adult C. hicoriae. The insects (C. hicoriae) were collected from natural field populations. The nematodes, Steinernema carpocapsae and Steinernema riobrave were both pathogenic to C. hicoriae yet there was no difference in their levels of virulence. In contract, Heterorhabditis indica was not pathogenic to C. hicoriae. Additional research is warranted to determine the potential of S. carpocapsae and S. riobrave to control C. hicoriae under field conditions.