Screening of Entomopathogenic Fungi Against Citrus Mealybug,Plannococcus citri(Hemiptera: Pseudococcidae)

Abstract

Planococcus citri (citrus mealybug) is a common and damaging citrus crop pest which has proven difficult to control using conventional methods, such as chemical pesticides and insect growth regulators, particularly late in the citrus growing season. The virulence of two entomopathogenic fungal species was studied in laboratory bioassays against the crawlers and adults of P. citri. Isolates of Metarhizium anisopliae and Beauveria bassiana, collected from citrus orchards in the Eastern Cape Province in SouthAfrica, were verified using and molecular techniques. Mealybug bioassays were performed in 24-well plates. Beauveria bassiana (GAR 17 B3) and M. anisopliae (FCM AR 23 B3) isolates both resulted in 67.5 % mortality of mealybug crawlers and B. bassiana (GB AR 23 13 3) resulted in 64 % crawler mortality with concentrations of 1 × 107 conidia/ml. These three isolates were further tested in multipledose bioassays to determine the median lethal concentration (LC50), which were 5.29 × 105 conidia/ml for the M. ...