Publications - Faculty - Recently Submitted Faculty Publications 2008
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Rogers - Pest Management Science
Effect of Pyriproxyfen, a Juvenile Hormone Mimic, on Egg Hatch, Nymph Development, Adult Emergence, and Reproduction of Asian Citrus Psyllid, Diaphorina Citri Kuwayama
Dhana Raj Boina, Michael E. Rogers, Nian Wang, and Lukasz L. Stelinski
Abstract. BACKGROUND: Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, is a vector of bacteria presumably responsible for Huanglongbing (HLB) disease in citrus. In this laboratory study, we investigated the activity of pyriproxyfen, a juvenile hormone mimic, on ACP eggs, nymphs and adults to evaluate its potential usefulness as a biorational insecticide for inclusion into an integrated pest management (IPM) program for ACP.
RESULTS: Pyriproxyfen applications exhibited strong ovicidal and larvicidal activity against ACP eggs and nymphs, respectively, in age- and concentration-dependent manners. Irrespective of egg age, timing, and method of treatment, a significantly lower percentage of eggs (5-29%) hatched into nymphs at the higher concentrations tested (64 and 128 µg mL-1). Only 0-36% of early instars (first, second and third) survived and emerged into adults, while 25-74% of late instars (fourth and fifth) survived and emerged into adults at the three higher concentrations tested (16, 32, and 64 µg mL-1). However, 15-20% of those adults that emerged from late instars exhibited morphological abnormalities. Furthermore, foliar application of pyriproxyfen affected the reproduction by significantly reducing the fecundity of females and viability of eggs deposited by females that emerged from treated fifth instars. Topical application of pyriproxyfen to adults at 0.04 µg per insect also significantly reduced fecundity and egg viability.
CONCLUSIONS: Application of pyriproxyfen at 64 µg mL-1 results in the highest inhibition of egg hatch in younger eggs (0-48 h old) laid before or after treatment and strongest suppression of adult emergence from early instars compared with other rates tested. Pyriproxyfen also markedly reduced female fecundity and egg viability for adults that were exposed either directly or indirectly. The direct (ovicidal and larvicidal) and indirect (transovarial) effects of pyriproxyfen against immature and adult ACP, respectively, suggest that integration of this insecticide as part of an IPM program should negatively impact ACP populations over time.
