In vitro effects of selected fungicides on three species of entomopathogenic fungi- potential biocontrol agent of chilli thrips Scirtothrips dorsalis Hood (Thysanoptera: Thripidae)

The chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is United States quarantine pest known to cause economic damage on a variety of crops worldwide. Originally from south Asia, chilli thrips is becoming widely distributed in tropical, subtropical and temperate areas. It attacks a wide range of crops belonging to more than 120 taxa within 40 families of plants. Chilli thrips has also been reported to be a vector of various viral and bacterial diseases, including peanut bud necrosis virus and Chlorotic fan spot virus of peanuts. Chemical control of this pest has always been the primary mode of its management. But, in recent years entomopathogenic fungi have been found effective against various thrips species. While use of these entomopathogenic fungi has become significant part of integrated pest management program but, still its use is questionable based on the inconsistent performance. In open field conditions the efficacy of these fungal pathogens depends greatly on abiotic conditions and may be affected by other fungicides used in field crop. To address this problem, in vitro study was conducted to determine the compatibility of three entomopathogens with wide range of fungicides used by vegetable and horticultural growers in south Florida. The 3 fungal pathogens used in the study were Beauvaria bassiana, Metarhizium anisopliae and Paecilomyces fumosoroseus. The selection of these entomopathogens was made on the basis of our preliminary studies where we found that Metarhizium anisopliae and Paecilomyces fumosoroseus were effective in regulating chilli thrips.