Testing the potential of entomopathogenic nematodes in attract-and-kill and autodissemination approaches in the control of Queensland fruit fly, Bactrocera tryoni

BACKGROUND: Many studies have demonstrated that tephritid fruitfly larvae are highly susceptible to entomopathogenicnematodes (EPNs) and may become infected as they enter the soil to pupate. However, the susceptibility of adult tephritidsand their suitability as EPN targets have been less studied. We performed laboratory assays with 12 Australian EPN strains ofHeterorhabditis bacteriophora,Heterorhabditis indicaandHeterorhabditis zealandicain adults of the Queensland fruitfly,Bac-trocera tryoni. Infective juveniles were delivered in a yeast hydrolysate solution that is attractive toflies. We also measuredtheflight ability of adults up to 3 days after treatment. RESULT: Flies that consumed the EPN-yeast preparation experienced 72.8-84% mortality. Between 33.5% and 46.2% of EPN-treated adults were still able tofly before death following treatment, mostly within thefirst day, thereby contributing toEPN dispersal. Another 31.9-39.9% of EPN-treatedflies that were unable tofly died as a result of EPN treatment. Overall,>65% offlies that died following EPN treatment had visible signs of infection and EPN reproduction. CONCLUSION: Our study is foundational to the development of attract-and-kill and autodissemination approaches involvingEPNs in fruitfly control. Furthermore,H. indicaandH. zealandicastrains showed the highest potential as biocontrol agentsagainst adultflies