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ARS Home » Southeast Area » Byron, Georgia » Fruit and Tree Nut Research » Research » Publications at this Location » Publication #332116
Research Project: New Tools for Managing Key Pests of Pecan and Peach

Location: Fruit and Tree Nut Research

Title: Will dual fungal infections increase mortality of Harmonia axyridis in natural populations?

Author
item HAELEWATERS, DANNY - Harvard University
item Shapiro Ilan, David
item Cottrell, Ted

Submitted to: IOBC/WPRS Bulletin (Abstract for Conference Proceedings)
Publication Type: Proceedings
Publication Acceptance Date: 8/13/2016
Publication Date: 1/1/2018
Citation: Haelewaters, D., Shapiro Ilan, D.I., Cottrell, T.E. 2018. Will dual fungal infections increase mortality of Harmonia axyridis in natural populations?. IOBC/WPRS Bulletin (Abstract for Conference Proceedings). 137:12-16.

Interpretive Summary: We evaluated whether the invasive multicolored Asian lady beetle and the native Olla v-nigrum lady beetle already infected by the ectoparasitic fungus Hesperomyces virescens ectoparasitic suffered increased mortality when also infected by the entomopathogenic fungus Beauveria bassiana. We found that mortality, when infected with both fungi, was higher than when infected with only one fungus for the native ladybird. However, in the invasive lady beetle, no differences were found between infection with either one fungus or both fungi. However, for both native and invasive ladybirds, we observed a significant increase in mortality caused by infection of H. virescens. This research adds significant data in the debate about the effects of the ectoparasitic H. virescens.

Technical Abstract: We evaluated whether the mortality to the invasive Harmonia axyridis and native Olla v-nigrum caused by Hesperomyces virescens ectoparasitic fungi could be increased by dual infections with the entomopathogenic fungus Beauveria bassiana. In our bioassays, the mortality in the co-infection treatments was higher than in the single-enemy treatments for the native ladybird. However, in the invasive H. axyridis, no differences were found between infection with one natural enemy and co-infection. These results suggest that applying B. bassiana in a biological control strategy against H. axyridis will not have the desired effect, but instead may harm H. virescens-infected native ladybirds. However, for both native and invasive ladybirds, we observed a significant increase in mortality caused by infection of H. virescens. This research adds significant data in the debate about the effects of Laboulbeniales.