Host stage and temperature for the rearing of Aridelus rufotestaceus (Hymenoptera: Braconidae), with notes on acceptance and suitability of 2 stink bug species

Abstract

Abstract Nezara viridula (L.) (Hemiptera: Pentatomidae) is a harmful pest of many agricultural crops in different parts of the world. This stink bug is the preferred host species of Aridelus rufotestaceus Tobias (Hymenoptera: Braconidae), an endoparasitoid of nymphs and adults of pentatomids. With the aim to improve the rearing procedure of this beneficial insect, the acceptance and suitability of all mobile stages of N. viridula (from first instar nymph to adult) were evaluated. At 25 °C, all host stages were accepted and suitable for A. rufotestaceus development, but the highest parasitoid cocoon and adult yields were obtained from second instar nymphs. The possibility to reduce the development time of A. rufotestasceus by increasing the rearing temperature was also evaluated, but 28 °C proved to be detrimental for parasitoid development, as shown by the very low cocoon and adult numbers obtained. The acceptance and suitability of the invasive pentatomid species Halyomorpha halys (Stål) for A. rufotestaceus was also tested. Female wasps were observed piercing H. halys nymphs with the ovipositor, but no cocoons were obtained, nor were larvae or head capsules detected in the exposed stink bugs.