Biological Invasions (2010) 12, 2649-2669

Li-Wei Wu, Shen-Horn Yen, David C. Lees and Yu-Feng Hsu (2010)
Elucidating genetic signatures of native and introduced populations of the Cycad Blue, Chilades pandava to Taiwan: a threat both to Sago Palm and to native Cycas populations worldwide
Biological Invasions 12 (8), 2649-2669
Abstract: Foreign plants are usually introduced for food or aesthetic reasons. Most of these plants are non-invasive, but can alter the evolutionary trajectory of the associated native insects or inadvertently spread potential pests. A hitherto poorly documented example is the rapid expansion of Chilades pandava, a Cycas-feeding butterfly. Since about 1990, large numbers of the Sago Palm Cycas revoluta were introduced into Taiwan. Invading or introduced with this hostplant, Ch. pandava has rapidly spread to all major parts of Taiwan. To trace the source of outbreaks, we sampled 810 specimens covering 50 Taiwanese localities and other regions using mitochondrial COII sequences. Overall haplotype diversity was high (h = 0.791), but only 29 haplotypes were found. The haplotype C which dominates outbreak populations from western Taiwan was endemic to the island. This is consistent with the hypothesis of a local range expansion of Ch. pandava, rather than an introduction. In addition, the Taiwanese Central Mountain Ridge may constitute a primary biogeographic barrier restricting gene flow between eastern and western populations. Our study not only flags an important new invasive insect that needs to be monitored and controlled within the horticultural trade and for in situ cycad conservation, but also provides a clearly documented case of the transformation of a native tropical butterfly into a pest via introduced horticultural plants.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
molecular biology - genes
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Chilades pandava	Cycad (Cycas)	Taiwan