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ARS Home » Southeast Area » Fort Pierce, Florida » U.S. Horticultural Research Laboratory » Subtropical Insects and Horticulture Research » Research » Publications at this Location » Publication #204529

Title: Effects of a particle film on biology and behavior of Diaphorina citri (Hemiptera: Psyllidae) and its infestations in citrus

Author
item Hall, David
item Lapointe, Stephen
item Wenninger, Erik

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2007
Publication Date: 6/1/2007
Citation: Hall, D.G., Lapointe, S.L., Wenninger, E. 2007. Effects of a particle film on biology and behavior of Diaphorina citri (Hemiptera: Psyllidae) and its infestations in citrus. Journal of Economic Entomology. 100:847-854.

Interpretive Summary: Surround WP, a kaolin-based hydrophilic particle film, was evaluated as a control strategy for Asian citrus psyllid in citrus. This psyllid is an important pest of citrus because it transmits a serious citrus disease called citrus greening disease or Huanglongbing. Surround is applied in water to plants and, when dry, leaves a film that can interfere with insect infestations and enhance plant growth. We found that a suspension of Surround in water was not acutely toxic to eggs, older nymphs or adults but that the presence of the dried particle film on leaves interfered with the ability of adults to grasp, walk and lay eggs on citrus leaves. In a 12-month study investigating infestations of Asian citrus psyllid on citrus treated monthly with Surround, cumulative reductions of 78% in adult numbers on mature leaves and of 60% in adult numbers on immature leaves were observed in treated trees compared to untreated trees. Numbers of eggs and nymphs on immature leaves were reduced by 85 and 78%, respectively, in trees treated with particle film. Reductions in infestation levels of Asian citrus psyllid in treated trees were attributed to the negative effects of the particle film on the ability of adults to grasp, move and lay eggs. Particle-film applications might be a viable component of a greening disease management program in citrus grown for the organic market.

Technical Abstract: Studies were conducted to investigate the effects of a kaolin-based hydrophilic particle film, Surround WP, on the biology and behavior of the psyllid Diaphorina citri Kuwayama, and to assess population densities of D. citri in citrus subjected to monthly applications of Surround WP. Laboratory investigations indicated a 3% (wt/vol) suspension of Surround WP in water applied directly was not acutely toxic to eggs, older nymphs or adults. Presence of the dried particle film on leaves interfered with the ability of adults to grasp and walk on citrus leaves. During a 30 s period, adults spent an average of 5 s moving on leaves with particle film compared to 16 s on leaves without particle film. When leaves were inverted, a significantly higher percentage of adults fell or flew from treated leaves (53%) than untreated leaves (16%). In a 12-month study investigating infestations of D. citri on citrus treated monthly with Surround WP, cumulative reductions of 78% in adult numbers on mature leaves and of 60% in adult numbers on flush shoots (immature leaves) were observed in treated trees compared to untreated trees. Numbers of eggs and nymphs per flush shoot were reduced by 85 and 78%, respectively, in trees treated with particle film. Reductions in infestation levels of D. citri in treated trees were attributed to the negative effects of the particle film on the ability of adults to grasp, move and oviposit. The suppressive effects of a Surround treatment against adult psyllids were degraded by rain.