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United States Department of Agriculture

Agricultural Research Service

Research Project: IPM TECHNOLOGIES FOR SUBTROPICAL INSECT PESTS

Location: Subtropical Insects and Horticulture Research

Title: Arrestment behavior in the polyphagous tropical root weevil Diaprepes abbreviatus

Authors
item Lapointe, Stephen
item Hall, David

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 28, 2009
Publication Date: June 1, 2009
Citation: Lapointe, S.L., Hall, D.G. 2009. Arrestment behavior in the polyphagous tropical root weevil Diaprepes abbreviatus. Journal of Economic Entomology. 102(3):992-998.

Interpretive Summary: An attractant for the tropical root weevil Diaprepes abbreviatus has been sought since the introduction of this pest of citrus to Florida in the 1960s. We constructed a unique 6-tunnel wind tunnel to study the response of adult weevils to odors under controlled experimental conditions. Weevils were introduced downwind and allowed to move upwind in response to odor sources (targets) placed upwind. We measured arrestment, or the cessation of movement upwind when the weevils encountered a target. Weevils did not respond in empty tunnels (no odor). Some movement upwind but no arrestment occurred when weevils were presented with young citrus leaves (flush). Citrus flush that had been fed upon by D. abbreviatus adults was highly attractive and caused the attraction and arrestment of both male and female adult D. abbreviatus. The effect was duplicated by placing organdy-enclosed feces (frass) sachets on undamaged citrus flush. The arrestment effect was eliminated, however, when fed-upon flush (FUF) was enclosed in a cage so that weevils could not contact the leaves. In these experiments, weevils continued to move upwind. The results of these tests lead us to conclude that host and mate location by D. abbreviatus is mediated by volatile and contact semiochemicals. This information will be essential for development of a trap for D. abbreviatus.

Technical Abstract: A semiochemical-based attractant for the tropical root weevil, Diaprepes abbreviatus (L.), has been sought since the introduction of this polyphagous pest to Florida in the 1960s. A 6-unit wind tunnel apparatus was constructed to allow multiple runs to be conducted simultaneously to test the response of D. abbreviatus adults to volatile and contact semiochemicals. Arrestment was measured as the number of weevils stopping and remaining on a target when presented with upwind target choices. No response (movement upwind) was observed when weevils were presented with a control (no odor). Some movement upwind but no arrestment occurred when weevils were presented with young citrus leaves (flush). Citrus flush that had been fed upon by D. abbreviatus adults was highly attractive and induced arrestment of both male and female adults. The effect was duplicated by placing organdy-enclosed feces (frass) on undamaged flush. The arrestment effect was eliminated, however, when fed-upon flush (FUF) was enclosed in a cage so that weevils could not contact the leaves. In these experiments, weevils continued to move upwind. The results of these tests lead us to conclude that host and mate location by D. abbreviatus is mediated by volatile and contact semiochemicals.

Last Modified: 4/21/2014
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