Controlling Dactylopius opuntiae with Fusarium incarnatum-equiseti species complex and extracts of Ricinus communis and Poincianella pyramidalis

In northeast Brazil, the cactus Opuntia ficus-indica is a key species for feeding livestock. However, productivity has been reduced by the cochineal scale Dactylopius opuntiae. Fusarium incarnatum-equiseti species complex (FIESC) strains obtained from D. opuntiae show potential as biological control agents. Furthermore, the insecticidal action of entomopathogenic fungi can be enhanced when used in conjunction with insecticides of plant origin. This study aimed to verify the insecticidal action of extracts of Ricinus communis and Poincianella pyramidalis separately and in combination with FIESC isolates against D. opuntiae. We evaluated the compatibility of FIESC 20-b isolates with aqueous and hydroethanolic extracts of R. communis and P. pyramidalis at w/v concentrations of 5, 10 and 20 %. The treatments used in the four bioassays against D. opuntiae were selected using the Biological Index model. The aqueous and hydroethanolic extracts of R. communis and P. pyramidalis were compatible with some FIESC 20-b isolates. The corrected mortality values at different bioassays ranged from 61.23 to 100 %. The insecticide action resulting from the combination of the URM6778 isolate with aqueous extract of R. communis was the highest, producing 100 % mortality on D. opuntiae. Our results indicate FIESC 20-b isolates and extracts of R. communis and P. pyramidalis are promising control agents for D. opuntiae, a low-cost technology and environmentally friendly.