Effects of pymetrozine, an antifeedant of Hemiptera, on Asian citrus psyllid, Diaphorina citri, feeding behavior, survival and transmission of Candidatus Liberibacter asiaticus.
BACKGROUND
Vector-borne plant disease management can be enhanced by deployment of antifeedants in addition to the use of broad-spectrum neurotoxic insecticides. The effects of pymetrozine on Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, feeding behaviour, survival and transmission of Candidatus Liberibacter asiaticus (Las), the presumed causal pathogen of huanglongbing, were investigated.


RESULTS
Pymetrozine applied at 52 and 104 µg mL(-1) to citrus plants [Swingle citrumelo (X Citroncirus webberi Ingram and Moore)] modified the feeding behavior of ACP and increased the amount of time spent performing non-penetration behaviors while decreasing the time spent performing ingestion behaviors compared with the controls 1 day after treatment. However, the antifeedant effect of pymetrozine subsided 5 days after application. Pymetrozine reduced the survival of both adults and nymphs on treated plants compared with the control. However, it had a greater impact on survival of nymphs than on survival of adults. Pymetrozine applied at 52 and 104 µg mL(-1) on Las-infected 'Valencia' sweet orange plants [Citrus sinensis L. (Osbeck)] reduced acquisition (12 and 21% respectively) and transmission (11 and 18% respectively) of Las by feeding ACP adults compared with the controls; however, these reductions were not statistically significant.


CONCLUSIONS
Pymetrozine exhibited moderate antifeedant effects by modifying the feeding behavior of ACP adults with short residual activity. The impact of pymetrozine on survival of nymphs was greater than on adults at the higher concentrations tested. Pymetrozine also reduced the acquisition and transmission of Las by feeding ACP adults up to 21 and 18%, respectively, compared with untreated controls.
Entomology and Nematology Department, Citrus Research and Education Center, University of Florida, Lake Alfred, FL 33850, USA. drboina@vt.edu
Dhana Raj
DR
Boina
Youngnam
Y
Youn
Svetlana
S
Folimonova
Lukasz L
LL
Stelinski
D000818:Animals; D005247:Feeding Behavior / Q000187:drug effects; D005260:Female; D006430:Hemiptera / Q000187:drug effects* / Q000382:microbiology / Q000502:physiology*; D007300:Insect Control; D007303:Insect Vectors / Q000187:drug effects* / Q000382:microbiology / Q000502:physiology*; D007306:Insecticides / Q000494:pharmacology*; D008297:Male; D050296:Microbial Viability; D010935:Plant Diseases / Q000382:microbiology* / Q000469:parasitology; D012230:Rhizobiaceae / Q000502:physiology*; D014227:Triazines / Q000494:pharmacology*
D007306:Insecticides; D014227:Triazines; C480311:pymetrozine