Exploratory survey in China for potential insect biocontrol agents of mile-a-minute weed, Polygonum perfoliatum L., in Eastern USA

A survey was undertaken in China between 1996 and 2001 for phytophagous insect fauna associated with mile-a-minute weed, Polygonum perfoliatum L. (Polygonaceae). The purpose was to identify potential biological control agents for this invasive plant in the eastern USA. The survey covered 23 provinces including northeastern China, where the climate is similar to that of the eastern USA, and southwest China, which is considered the center of origin of the family Polygonaceae. About 111 insect species were collected and identified, although some immatures were not identified to species level. Based on information from the literature and results from laboratory and field tests on host range, severity of damage, and widely distributed field populations, a weevil, Rhinoncomimus latipes Korotyaev (Coleoptera: Curculionidae) was regarded as the most promising agent. Three oligophagous leaf beetles, Smaragdina nigrifrons (Coleoptera: Eumolpidae), Gallerucida bifasciata (Coleoptera: Chrysomelidae), and Galerucella placida (Coleoptera: Chrysomelidae), as well as a geometrid moth, Timandra griseata (Lepidoptera: Geometridiae), were dominant at most of the surveyed sites. All impacted the growth and reproduction of mile-a-minute weed. One bug, Cletus schmidti (Hemiptera: Coreidae), and one sawfly, Allantus nigrocaeruleus (Smith) (Hymenoptera: Tenthredinidae), are recommended for further evaluation for host specificity.