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United States Department of Agriculture

Agricultural Research Service

Title: Dietary Influences on the Terpenoids Sequestered by the Biological Control Agent Oxyops Vitiosa: the Effect of Plant Volatiles from Different Melaleuca Quinquenervia Chemotypes and Laboratory Host Species

Authors
item Wheeler, Gregory
item Massey, L. - STUDENT
item Southwell, I. - WOLLONGBAR AG. INST.

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 8, 2002
Publication Date: January 20, 2003
Citation: Wheeler, G.S., Massey, L.M., Southwell, I.A. 2003. Dietary influences on the terpenoids sequestered by the biological control agent oxyops vitiosa: the effect of plant volatiles from different melaleuca quinquenervia chemotypes and laboratory host species. Journal of Chemical Ecology.

Interpretive Summary: The melaleuca leaf-feeding weevil is from Australian and has been imported to Florida for the biological control of the invasive weed Melaleuca quinquenervia. The larvae of this species feed on the leaves of this plant and produce a shiny orange secretion that covers their body. Previous results indicated that a compound in this secretion, viridiflorol was absorbed from the leaf and this compound repels a predator, the red imported fire ant, Solenopsis invicta. When the larvae feed on a different type of M. quinquenervia, which lacked the compound that repelled ants, viridiflorol, but one rich in a different compound, trans-nerolidol, similar protection against ants occurred. Solvent washes of these larvae indicated that trans-nerolidol was absorbed from M. quinquenervia leaves and it repelled ants when it coated dog food at the same concentrations as found on the larvae (17.5, 35.0, and 52.5 micrograms/mg). Another compound beta-caryophyllene also repelled ants when it coated dog food at concentrations that similar to those on the O. vitiosa larvae (3.5 and 35 microggrams.When the O. vitiosa larvae were fed leaves from different plant species, similar repellent activity was found. This activity was traced to several of the same compounds (e.g. 1,8-cineole, viridiflorol) found to be repellent in their normal host M. quinquenervia. These weevil larvae are opportunistic absorbing the primary compounds in their host leaves that confer protection from predators.

Technical Abstract: The weevil Oxyops vitiosa is an Australian species imported to Florida, USA for the biological control of the invasive species Melaleuca quinquenervia. The larvae of this species feed on the leaves of their host and produce a shiny orange secretion that covers their integument. Previous results indicated that a major component of this secretion, viridiflorol is sequestered from the host plant and repels a generalist predator, the red imported fire ant, Solenopsis invicta. When the larvae feed on a different chemotype of M. quinquenervia, which lacked viridiflorol but one rich in a different sesquiterpene, trans-nerolidol, similar protection occurred. Solvent washes of these larvae indicated that trans-nerolidol was sequestered from M. quinquenervia leaves and repelled S. invicta workers when applied to dog food baits at physiological concentrations (17.5, 35.0, and 52.5 micrograms/mg). Additionally, beta-caryophyllene also repelled S. invicta workers when applied to dog food baits at concentrations that approximated those in the O. vitiosa larval secretions (3.5 and 35 micrograms/mg). When the O. vitiosa larvae were fed leaves from laboratory hosts (non-field hosts) similar repellent activity was found. This activity was traced to several of the same compounds (e.g. 1,8-cineole, viridiflorol) found to be active in their field host M. quinquenervia. These weevil larvae are opportunistic sequestering the primary terpenoids in their host leaves that confer anti-predator activity.

Last Modified: 12/17/2014
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