ARS | Publication request: ALTERNATIVE PEST CONTROL TACTICS IN PECAN

Submitted to: Southeastern Pecan Growers Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 26, 2006
Publication Date: July 1, 2006
Citation: Shapiro Ilan, D.I., Cottrell, T.E., Gardner, W., Behle, R.W., Nyczepir, A.P., Wood, B.W. 2006. Alternative pest control tactics in pecan. Proceedings of the Southeastern Pecan Growers Meeting. 99:86-94.

Interpretive Summary: The pecan weevil is a key pest of pecan. We are developing insect-killing nematodes or fungi as alternative tactics for control of the pecan weevil. Field studies with certain nematode species yielded 80% weevil control in 2004 and 50% in 2005. To enhance weevil suppression superior nematode strains are being developed through hybridization and lab screening; these new strains will be field-tested in the coming season. A white muscardine fungus caused up to 80% weevil mortality in field tests in 2005, and appears to be especially promising when cultivated into the soil or when applied directly to the trunk. Another fungus, the green muscardine, caused 80% weevil mortality 15 days post-application. M. anisopliae can be applied in a fungus-band that is attached to the trunk. In another study, we are focusing on controling the pecan root-knot nematode, which (unlike the insect-killing nematodes) is a pest that attacks pecans. Our study involves killing the bad nematodes with the good nematodes. Initial results from this approach indicate some suppression of the pest (bad) nematodes u

Technical Abstract: We are developing entomopathogenic nematodes or fungi as alternative tactics for control of the pecan weevil. When the Italian strain of Steinernema carpocapsae was tested in the field, up to 80% weevil mortality was observed in 2004, but only 50% in 2005. To enhance weevil suppression superior nematode strains are being developed through hybridization and screening; these new strains will be field-tested in the coming season. The fungus, Beauveria bassiana, caused up to 80% weevil mortality in field tests, and appears to be especially promising when cultivated into the soil or when applied directly to the trunk. Metarhizium anisopliae caused 80% weevil mortality 15 days post-application. M. anisopliae can be applied in a fungus-band that is attached to the trunk. In another study, we are focusing on alternative tactics to control the pecan root-knot nematode, Meloidogyne partityla. In a greenhouse study on pecan seedlings, application of certain entomopathogenic nematode treatments caused some suppression in reproduction of the pecan root-knot nematode,; these effects must be researched further.