EFFECT OF A NEEM BIOPESTICIDE ON REPELLENCY, MORTALITY, OVIPOSITION, AND DEVELOPMENT OF DIAPHORINA CITRI (HOMOPTERA: PSYLLIDAE)

A. A. Weathersbee, C. L. McKenzie
2005 Florida Entomologist  
A BSTRACT The biological effects of a neem-based biopesticide, containing 4.5% azadirachtin, were assessed against the Asian citrus psyllid, Diaphorina citri Kuwayama, a recently introduced insect pest and potential disease vector of citrus in the United States. Over the concentration range 11-180 ppm azadirachtin, no mortality of adult psyllids was observed when exposed to treated plants. Adult psyllids demonstrated a small but significant repellent effect from treated plants in a choice
more » ... s in a choice experiment, but showed no preference to oviposit on treated or untreated plants. Psyllid nymphs were susceptible to azadirachtin at very low concentrations and activity perhaps was due to developmental inhibition. At a concentration of 22.5 ppm azadirachtin, ecdysis was not observed past 4 days after treatment and all nymphs were dead within 7 days. The densities of psyllid nymphs on treated plants exposed to a greenhouse population were significantly reduced by concentrations as low as 10 ppm azadirachtin. Over the range of concentrations used in these experiments, the product caused no phytotoxicity to tender foliage of either citrus or orange jasmine plants. Field trials are warranted to determine suitability of neem-based biopesticides for inclusion in citrus integrated pest management programs.
doi:10.1653/0015-4040(2005)88[401:eoanbo]2.0.co;2 fatcat:5hut4q4yfncitouiv4cdwvqxwe