Host-Range and Distribution ofEucerocoris suspectus(Hemiptera: Miridae), a Potential Biological Control Agent for the Paperbark TreeMelaleuca quinquenervia(Myrtaceae)

Abstract

The Australian paperbark tree, Melaleuca quinquenervia (Cavier) S. T. Blake, is a serious economic and environmental pest in Florida. One of the most damaging insects found attacking M. quinquenervia during surveys for biocontrol agents in its home range (Australia) was the leaf-blotching bug Eucerocoris suspectus Distant (Hemiptera: Miridae). Adults and nymphs of E. suspectus feed on young leaves and shoots. Their feeding kills leaf tissue surrounding the feeding site, leaving a distinctive, brown, blotch scar. Laboratory host-range studies showed 6 nontarget plant species to be at risk from E. suspectus. However, our extensive field survey data indicate that none of these plants are used as field hosts by E. suspectus. We conducted 8 intensive field searches for E. suspectus feeding damage on >60 plant species at 6 sites. Damage was only noted on Melaleuca spp., except on 1 occasion, where minor feeding damage was found on 2 Lumnitzera racemosa trees adjacent to a more heavily damaged M. quinquenervia tree. Thus, although E. suspectus completed its life cycle on several plant species in the laboratory (albeit at a much lower level than on M. quinquenervia ), in the field, feeding damage is restricted to Melaleuca spp. in the M. leucadendra (L.) L. complex, and rarely, Callistemon spp. The narrow host-range, broad habitat tolerances, and extensive damage caused by this insect should make it a valuable biological control agent if released in Florida.