Publications - Faculty - Recently Submitted Faculty Publications 2008
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Stelinski - Pest Management Science
Effect of Candidatus Liberibacter asiaticus infection on susceptibility of Asian citrus psyllid, Diaphorina citri, to selected insecticides
Siddharth Tiwari, Dhana Raj Boina, Kirsten Pelz-Stelinski and Lukasz L. Stelinski
Abstract
BACKGROUND: Microorganisms are known to alter insect host physiology, which may benefit or harm the host. In the present investigation, we determined the effect of Candidatus Liberibacter asiaticus (Las), a bacterium presumably responsible for causing huanglongbing (HLB) disease in citrus, on the physiology of its vector, the Asian citrus psyllid (ACP) Diaphorina citri Kuwayama. Specifically, we determined the effects of Las infection on susceptibility of ACP to selected insecticides. Furthermore, the total protein content and general esterase activity was quantified in Las-infected and uninfected ACP to gain insight into the possible mechanism(s) responsible for altered susceptibility to insecticides due to Las infection.
RESULTS: Las-infected ACP were more susceptible to 5 insecticides of different modes of action than uninfected controls. Total protein content was significantly lower in Las-infected (221.13 ± 5.78 µg/ml) than uninfected (341.93 ± 26.58 µg/ml) ACP. Likewise, general esterase enzyme activity was significantly lower in Las-infected (55.88 ± 2.31 nmol/min/mg protein) than uninfected ACP (71.01 ± 3.12 nmol/min/mg protein).
CONCLUSION: Susceptibility of ACP to insecticides from five major classes increased due to Las infection compared with uninfected controls. Lower total protein content and reduced general esterase activity in Las-infected than uninfected ACP may partly explain the higher insecticide susceptibility of Las-infected ACP. Our results suggest a fitness cost in ACP due to Las infection
