D3429: Mesocosm studies of three commercial mycoinsecticide strains against the citrus pest, Diaphorina citri

The use of commercial mycoinsecticides for the control of the Asian citrus psyllid (ACP), Diaphorina citri Kuwayama (Hemiptera: Liviidae) has become more common as the need for chemical pesticide alternatives increases. Our mesocosm study consisted of enclosing a BugDorm cage within a Quonset cage with one 3-gallon potted plant per Bugdorm in the field and infesting each cage with 100 unsexed, adult D. citri to assess the efficacy of three commercial mycoinsecticide-derived fungal strains (Cordyceps (Isaria) javanica Apopka 97, Cordyceps (Isaria) fumosorosea Ifr9901, and Beauveria bassiana ANT-03) under field conditions. Conidial formulations were sprayed at a rate of 3.96×10⁶ viable spores ml^-1 (equivalent to 1.5×10¹² spores per acre), comparable to low-dose field application rates. The study was run in triplicate, and one of three caged plants per treatment was used as an intra-treatment control where the Henderson-Tilden correction calculation was used to control for natural insect mortality post-spray. Results indicated that strain ANT-03 induced higher mortality than the untreated control (P< 0.05). Results also showed marginal differences between the other two mycoinsecticides and untreated control, although no significant differences were determined. These findings showed that at low-dose field application rates, ANT-03 was capable of inducing mortality at approximately 40%. Future studies will explore high-dose application rates, in addition to various formulation applications to determine the optimum candidate to recommend for control of D. citri in grove applications.