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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #260682
Title: Compatibility of beneficial nematodes and parasitic wasps for control of Indianmeal moth, a pest of stored pecans

Author
item Shapiro Ilan, David
item MBATA, GEORGA - Fort Valley State University
item HUDSON, WILL - Fort Valley State University

Submitted to: Pecan Grower
Publication Type: Trade Journal
Publication Acceptance Date: 9/29/2010
Publication Date: 10/28/2010
Citation: Shapiro Ilan, D.I., Mbata, G., Hudson, W. 2010. Compatibility of beneficial nematodes and parasitic wasps for control of Indianmeal moth, a pest of stored pecans. Pecan Grower. 22(2):10-17.

Interpretive Summary: In terms of pecan insect management, the bulk of attention is justifiably devoted to protecting the crop during the growing season. However, insect damage can also occur once the pecans are harvested and in storage. Indianmeal moth is one of the primary pests that can attack stored pecans. Due to environmental and regulatory concerns, alternative pest control solutions for suppression of Indianmeal moth are needed. Two biological control agents that have shown promise include parasitic wasps and beneficial insect-killing nematodes. Our objective was to determine the compatibility of these two biocontrol agents and their potential to be applied simultaneously for Indianmeal moth control. A combination of the nematode (called Heterorhabditis indica) and the parasitoid wasp (called Habrobracon hebetor) was observed to increase the mortality of Indianmeal moth. The interaction between the nematodes and parasitoid wasps on Indianmeal moth mortality was positive. Release of parasitoids or application of nematodes alone generated between 62.25 and 71.25% mortality of the Indianmeal moth larvae, whereas combination of the two resulted in = 98%. Parasitoid wasps did not differentiate between Indianmeal moth larvae that were already infected with nematodes versus uninfected larvae. In contrast, nematodes preferentially infected Indianmeal moth larvae that were previously parasitized by wasps. Nematode reproduction inside Indianmeal moth larvae was not affected by presence of the wasp. Reproduction/development of the wasp, however, was negatively affected by presence of the nematode. The combined application of nematode and wasps for the control of Indianmeal moth may be beneficial if the detrimental effects of the nematode on the parasitoid reproduction can be minimized through optimum timing.

Technical Abstract: In terms of pecan insect management, the bulk of attention is justifiably devoted to protecting the crop during the growing season. However, insect damage can also occur once the pecans are harvested and in storage. Indianmeal moth is one of the primary pests that can attack stored pecans. Due to environmental and regulatory concerns, alternative pest control solutions for suppression of Indianmeal moth are needed. Two biological control agents that have shown promise include parasitic wasps and beneficial insect-killing nematodes. Our objective was to determine the compatibility of these two biocontrol agents and their potential to be applied simultaneously for Indianmeal moth control. A combination of the nematode (Heterorhabditis indica) and the parasitoid wasp (Habrobracon hebetor) was observed to increase the mortality of Indianmeal moth. The interaction between the nematodes and parasitoids on Indianmeal moth mortality was not antagonistic and may be either additive or synergistic. Release of parasitoids or application of nematodes alone generated between 62.25 and 71.25% mortality of the Indianmeal moth larvae, whereas combination of the two resulted in = 98%. Parasitoid wasps did not differentiate between Indianmeal moth larvae that were already infected with nematodes versus uninfected larvae. In contrast, nematodes preferentially infected Indianmeal moth larvae that were previously parasitized by wasps. Nematode reproduction inside Indianmeal moth larvae was not affected by presence of the wasp. Reproduction/development of the wasp, however, was negatively affected by presence of the nematode. The combined application of nematode and wasps for the control of Indianmeal moth may be beneficial if the detrimental effects of the nematode on the parasitoid reproduction can be minimized through optimum timing.