Author
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Pemberton, Robert |
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Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 12/4/2009 Publication Date: 7/6/2010 Citation: Pemberton, R.W. 2010. Laboratory host range testing of Lilioceris sp. near impressa (Coleoptera: Chrysomelidae) – a potential biological control agent of air potato, Dioscorea bulbifera (Dioscoreaceae). Biocontrol Science and Technology. Vol. 20, No. 6, pg.567-587. Interpretive Summary: Air potato, Dioscorea bulbifera, is an invasive, herbaceous, climbing vine, which dominates invaded native vegetation in Florida. Herbicidal control of the weed is expensive and causes injury to non-target vegetation with which the weed is associated. The discovery of Lilioceris sp. near impressa defoliating D. bulbifera vines and feeding on the bulbils (aerial tubers) in the Katmandu Valley of Nepal initiated a project to assess the potential of this leaf beetle for biological control of air potato in Florida. Quarantine host specificity tests were conducted on 41 plant species in 24 families and 13 orders, with 26 species outside of the Dioscoreaceae and 15 species within the Dioscoreaceae. Adults test fed (nibbled) on 4/12 tested Dioscorea species but no larval feeding, nor development occurred on any plant except for the target plant D. bulbifera. The larvae feed gregariously and quickly skeletonize offered leaves of air potato. Air potato bulbils that received any feeding damage to the primary meristematic region did not sprout. The ability of the beetle larvae and adults to feed on the bulbils is important because the plants rarely flowers or produces fruit in Florida, so the aerial tubers are the primary means of persistence and spread. The adults can live for several months without food. Given the beetle’s very narrow diet and the damage it causes to the weed, it has great promise as a biological control of air potato. Technical Abstract: Air potato, Dioscorea bulbifera, is an invasive, herbaceous, climbing vine, which dominates invaded native vegetation in Florida. The fortuitous discovery of Lilioceris sp. near impressa defoliating D. bulbifera vines and feeding on the bulbils (aerial tubers) in the Katmandu Valley of Nepal initiated a project to assess the potential of this leaf beetle for biological control of air potato in Florida. Quarantine host specificity tests were conducted on 41 plant species in 24 families and 13 orders, with 26 species outside of the Dioscoreaceae and 15 species within the Dioscoreaceae. Adults test fed (nibbled) on 4/12 tested Dioscorea species but no larval feeding, nor development occurred on any plant except for the target plant D. bulbifera. The larvae feed gregariously and quickly skeletonize offered leaves of air potato. Air potato bulbils that received any feeding damage to the primary meristematic region did not sprout. The ability of the beetle larvae and adults to feed on the bulbils is important because the weed rarely flowers or produces fruit in Florida, so the aerial tubers are the primary means of persistence and spread. The adults can live for several months without food. This extremely specialized herbivore from the part weed’s native range appears to have great promise as a biological control of air potato. |
