Temperature and host stage suitability for the parasitoid, Aridelus rufotestaceus

The braconid parasitoid Aridelus rufotestaceus was first discovered in the US in 2007 attacking nymphs of the Southern green stink bug, Nezara viridula, in Georgia. We evaluated parasitoid survival, development, and emergent adult size and sex ratio when reared in hosts (Nezara viridula) stung as 2nd, 3rd, 4th, and 5th nymphal instars and as adults. We evaluated each of these host stages at 20, 25, and 30C constant temperature (L:D 14:10). The 3rd and 4th instars were the best overall host stages, regardless of temperature, and parasitoid survival, size, and sex ratio parameters were comparable at 20 and 25C, but parasitoid survival was significantly reduced at 30C. The host stage preference (limited ability to successfully attack adult stage, which overwinters) and sensitivity to warmer temperatures may limit the effectiveness of this parasitoid in the southern US.