Activity of Fungal Entomopathogens against Pineapple Pink Mealy Bug [Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae)]

Entomopathogenic fungi (EPF) are promising biological control agents against pink pineapple mealybug (PPMB), Dysmicoccus brevipes (Cockerell) (Hemiptera: Pseudococcidae), an important insect pest of pineapple. Three EPFs, namely, Metarhizium anisopliae, Beauveria sp., and Lecanicillium lecanii, were tested against PPMB crawlers and adults in a laboratory. Methods of EPF application were direct spraying on insects and pineapple leaf and dipping with a single dosage of a 1 mL suspension of 1x10⁸ spores/mL. Mortality rates were determined at 1 to 10 days after treatment (DAT). The results indicated that the three EPFs showed pathogenicity against the PPMB at varying degrees. At 10 DAT, a 100% mortality rate was observed for the treatment of M. anisopliae on all application methods and PPMB stages, followed by L. lecanii ( 55.91%) and Beauveria sp. ( 27.98 %). No significant difference in the percentage of infection was observed between PPMB crawlers and adults. Moreover, a slightly higher percentage of infection was observed in the spraying of the conidial suspension at 1x 10⁸ but this was not statistically significant compared to the leaf dipping method. This study suggests that among the EPFs used, M. anisopliae has the potential to be used as a biological control against PPMB.