Biological Invasions (2011) 13, 659-667

Zhong-Shi Zhou, Jian-Ying Guo, J.P. Michaud, Min Li and Fang-Hao Wan (2011)
Variation in cold hardiness among geographic populations of the ragweed beetle, Ophraella communa LeSage (Coleoptera: Chrysomelidae), a biological control agent of Ambrosia artemisiifolia L. (Asterales: Asteraceae), in China
Biological Invasions 13 (3), 659-667
Abstract: The ragweed beetle, Ophraella communa, is a potential biological control agent of common ragweed that appeared in Nanjing City in 2001 and has since dispersed throughout southeast China. We compared the cold hardiness of five different O. communa populations by measuring the supercooling point (SCP), water and glycerol contents of adult beetles. All indices of cold hardiness varied significantly among the sampled populations. Male beetles from the most northerly population (Nanjing) had the lowest water content of any sampled and, although female beetles from Nanchang and Miluo had water content similar to those from Nanjing, they were still lower than those of females from Fuzhou and Wuchang. Beetles from the most southerly population (Fuzhou) had the highest SCP, although Nanchang males were not significantly different from Fuzhou males. Glycerol content yielded resolution of populations as follows: Nanjing > Wuchang = Miluo = Nanchang > Fuzhou, with beetles from Nanjing yielding twice the glycerol content of Fuzhou beetles. These results suggest that overwintering O. communa use freeze avoidance to survive winter cold and that geographically separated populations of O. communa are diverging with respect to their baseline cold hardiness in accordance with the severity of low temperatures experienced during the coldest winter months in each locality. The apparent ability of O. communa to rapidly adapt to different climatic conditions is predicted to facilitate its continued range expansion across mainland China, with consequent benefits in terms of fortuitous biological control of common ragweed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Fang Hao Wan, J.P. Michaud

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Ambrosia artemisiifolia (weed)		China (NE)
	Ambrosia artemisiifolia (weed)		China (NE)
Ophraella communa (weed bioagent)	Ambrosia artemisiifolia (weed)		China (south)
Ophraella communa (weed bioagent)	Ambrosia artemisiifolia (weed)		China (NE)