Laboratory Study on the Efficacy of Metarhizium anisopliae (Deuteromycota: Hyphomycetes) in Controlling Coptotermes gestroi (Isoptera: Rhinotermitidae)
Maketon, Monchan; Sawangwan, Patcharin; Sawatwarakul, Weethima
Eight entomopathogenic fungi were tested for controlling the subterranean termite, Coptotermes gestroi (Wasmann 1896). Metarhizium anisopliae (Metschnikoff 1879), Sorokinstrain CKM-048, was found to be the most virulent strain with 89 percent mortality within 14 days at the concentration of 3 x 108 conidia/ml. Further studies found the optimum temperature and concentration for the fungal growth to be 27±1oC and 3 x 108 conidia/ml. A comparison between a conidial suspension sprayed and a baited method for wood protection revealed that the spray method of 3x108 conidia/ml resulted in 100% termite mortality after 1 month. There was no virulence difference between termite generations or termite castes. Studies for infection steps of M anisopliae on C gestroi by scanning electron microscopy were also recorded, these steps including adhesion, germination, penetration, colonization and finally conidiogenesis.