The host range and biology of the mesquite psyllid Heteropsylla texana

Abstract

Prosopis spp. areintroduced rangeland weeds in Australia. In asearch for biological control agents, thepsyllid Heteropsylla texana, which causessevere distortion to growing leaf and floralshoots, was imported from Texas, USA forhost range testing in quarantine facilities.No-choice tests were conducted on 60 plantspecies including P. pallida, P. velutinaand P. juliflora. In these trials, adultssurvived on 45 non-target plants but ovipositedonly on the Prosopis spp., Dichrostachys spicata and Acaciabidwillii. Nymphs developed to ovipositingadults on all Prosopis spp. and both D. spicata and A. bidwillii. Developmentof small numbers of adults on D. spicataand A. bidwillii occurred for only onegeneration. Damage was noticed only on Prosopis spp. In multiple-choice trials usingthree plant species, oviposition and subsequentdevelopment of eggs and nymphs to adults tookplace on P. pallida and D. spicatabut not on A. bidwillii. The low numbersdeveloping, the longer development times toadults when reared on D. spicata and A.bidwillii, and the failure of these plantsto sustain populations beyond one generationindicate that these plants are not hosts ofH. texana. While adult survival on manytest plants may imply that adult feedingoccurred, the risk to populations of theseplants in the field is negligible. It wasconcluded that H. texana is specific toProsopis spp. and could be released inAustralia for control of Prosopis spp.Observations of the biology of this speciesmade during the course of rearing andexperimentation indicated that nymphs developedthrough five instars to adults in 7–8 days sothat total development from egg to adult takes13–17 days. Females produce up to 100 eggs.