Host plants may influence indirectly biological characteristics of predators, on a positive or negative way, poiting out the importance of studies evaluating the effect of cultivars on the third trophic level. This study evaluates the biological aspects and predatory capacity of Podisus nigrispinus adults fed Alabama argillacea larvae reared on cotton genotypes. The predator was fed daily with fourth instar larvae reared on leaves of the following genotypes CNPA Precoce 1 (hirsute), CNPA 9211-31 (high gossypol level), CNPA 9211-41 (medium gossypol level) and GL2 GL3 (gossypol glandless). The pre-oviposition, oviposition and post-oviposition periods and the oviposition capacity of P. nigripinus were not affected when preyed on cotton leafworms reared on the listed cotton genotypes. Mean weight of predator females was higher (126.2 mg) when they fed on A. argillacea reared on GL2 GL3 cotton leaves, in comparison to the observed weight (96.2mg) of P. nigripinus females fed on larvae reared on CNPA 9211-41. Longevity of P. nigrispinus ranged 30.7 to 31.5 days for females and 38.0 to 66.3 days for males. P. nigrispinus females preyed 125.2 to 184.0 A. argillacea larvae during its adult stage, while adult males preyed 135.7 to 205.0 leafworms. Using plant resistance in association with P. nigrispinus is viable to control A. argillacea, because resistant genotypes do not influence negatively the biological characteristics of the predator.
cotton leafworm; predator; biological control; plant resistance