Environmental contamination with Metarhizium anisopliae from fungal bands for control of the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae)

Abstract

Our objective was to determine whether conidia from non-woven fiber bands impregnated with Metarhizium anisopliae F 52 could be spread to other parts of the environment, and whether Anoplophora glabripennis could become infected with conidia dispersed from fungal bands. In the field, bands containing M. anisopliae were hung at 3 m height on 15 trees. Bark samples were taken 10, 20, and 30 cm above the bands and 10, 30, and 60 cm below the bands 2, 5, and 9 days after band placement to quantify conidial densities. There were more conidia in samples taken below bands compared with samples taken above bands. A significant positive correlation was found between rainfall and the occurrence of conidia on any of the bark samples. A laboratory study was conducted to determine whether conidia from M. anisopliae fungal bands could be spread to other parts of the environment by A. glabripennis adults and whether A. glabripennis could become infected by conidia dispersed from fungal bands. One or five adult A. glabripennis were used to contaminate artificial environments with conidia. All adults subsequently exposed to contaminated environments were killed by fungal infection. Beetles exposed to environments that had been contaminated by five beetles died in fewer days compared with environments contaminated by one beetle. Beetles in both density treatments died in fewer days than beetles exposed to environments without M. anisopliae conidia. Our results indicate that environmental contamination with conidia from fungal bands can occur, and that adult A. glabripennis can acquire infection from a contaminated environment.

Keywords:

• Anoplophora glabripennis
• Metarhizium anisopliae
• Asian longhorned beetle
• transmission
• infection
• Cerambycidae

Acknowledgements

We thank John Vandenberg for indispensable advice and comments. Fungal bands were generously provided to us by Jarrod Leland (while with USDA-ARS in Stoneville, MS). James Booth and Francoise Vermeylen provided critical assistance with statistical modeling and assessments. Technical assistance was provided by Joshua Hannam, Sana Gardescu, James Reilly, James Cheng, and Corinne Brenner. Studies were funded by a grant from the Alphawood Foundation to A.E.H. We thank the State University of New York College of Environmental Science and Forestry (SUNY ESF) for access to the Svend O. Heiberg Memorial Forest.