Potential of predatory neotropical ladybirds and minute pirate bug on strawberry aphid

Abstract

Laboratory trials were performed to determine the impact of three Neotropical predatory coccinellids (Cycloneda sanguinea, Eriopis connexa and Coleomegilla quadrifasciata) and a minute pirate bug (Orius insidiosus) on Chaetosiphon fragaefolii, an important strawberry aphid pest. The predation on C. fragaefolii nymphs and adults, as well as the time to the first attack of all predators were compared with predation on Aphis gossypii. Predator preferences for prey and aphid defensive behavior were also evaluated. Moreover, the effect of coccinellids on C. fragaefolii population growth was assessed in experimental greenhouse conditions. The predation rate varied among predators, being significantly lower for O. insidiosus than for the coccinellids. Consumption was higher on A. gossypii than on C. fragaefolii, regardless of the aphids developmental stage. The time to the first attack of all predators was longer in the presence of C. fragaefolii. Walking away and cornicle secretion were the most common antipredator behaviors of aphid against coccinellids and O. insidiosus, respectively. Coccinellids preferred A. gossypii over C. fragaefolii, while O. insidiosus showed indifference. Cycloneda sanguinea and E. connexa exhibited the highest suppression effect on the growth rate of C. fragaefolii. Thus, the four predators evaluated could contribute to reduce strawberry aphid populations, especially C. sanguinea and E. connexa.