Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/17/2009
Publication Date: 8/1/2009
Citation: Wang, Y., Ding, J., Wheeler, G.S., Purcell, M., Zhang, G. 2009. Heterapoderopsis bicallosicollis (Coleoptera: Attelabidae): A Potential Biological Control Agent for Triadeca sebifera. Environmental Entomology, 38(4):1135-1144. Interpretive Summary: The weed Chinese tallow is an invasive plant of the southeastern US invading wetlands, coastal, and disturbed habitats. With its explosive growth rate and capability of spreading to new areas, Chinese tallow is considered one of the 10 worst weeds in the US by the Nature Conservancy This species was imported originally from China as a seed oil crop but now has escaped cultivation and is considered a noxious weed throughout the region. From 1998 to 2004 the Florida Department of Environmental Protection spent three quarters of a million dollars treating more than 4000 acres. As this plant was cultivated in China for hundreds of years, numerous herbivores have been identified that decrease its production. These herbivores are being investigated for biological control of this weed here in the US. One such candidate under consideration is a leaf-rolling weevil Apoderus bicallosicollis. The results of field and laboratory experiments in China indicate that this weevil will lay eggs, feed, and complete develop only on the weed Chinese tallow. This weevil species is now under consideration to be introduced to the US under quarantine where it’s suitability for safe and effective biological control can be investigated with North American plant species.
Technical Abstract: Native to China, Chinese tallow, Triadica sebifera (L.) Small (Euphorbiaceae), is an invasive plant in the southeastern United States of America. The leaf-rolling weevil, Apoderus bicallosicollis Voss is a common herbivore attacking the plant in China. To evaluate its potential as a biological control agent of the plant, biological characteristics, native distribution, thermal physiology and host-specificity of the weevil were studied in China. The weevil occurs over a wide, native, geographic range and its immatures successfully develop between 15-35º C, indicating its physiological potential to establish and persist throughout the range of climatic conditions under which the target plant grows in the US. Adults feed on leaves and make feeding holes. Before oviposition, the female adult rolls a leaf to make sealed leaf rolls called nidi, and then lays 1-2 eggs inside. Eggs, larvae and pupae occur only inside nidi and larvae survive only when they develop inside the tallow nidus. This requirement makes the weevil highly host-specific to T. sebifera. Laboratory no-choice tests indicated that among 54 species from 8 families the adults fed on 3 plant species, T. sebifera, Sapium chihsinianum S. K. Lee, Phyllanthus urinaria L., but only oviposited on T. sebifera. Multiple choice tests showed that the adults only laid eggs on T. sebifera and when feeding strongly preferred T. sebifera over Phyllanthus urinaria. In the field, no damage and no eggs were found on 32 plant species of 17 families growing near T. sebifera. Given that Chinese tallow is the only species in the genus Triadica in the US, the results of this study suggested that A. bicallosicollis is a potential biological control agent of Chinese tallow in the US and should be considered to be imported into quarantine in the US for further tests on native North American species.