The Study On Diapause And Host Selection Suitablity Of Asian Gypsy Moth (Lymantria Dispar Asiatica)

Gypsy moth(Lymantria dispar Linnaeus) is a kind of worldwide pest, which is mainly divided into2subspecies(European gypsy moth and Asian gypsy moth). European gypsy moth was introduced to USAwhich caused a great damage and aroused highly attention. Former study showed Asia gypsy moth could harm about500kinds of trees, which is more than European gypsy moth(250species). Moreover female Asia gypsy moth is reported to maitian strong flight ability. So Asia gypsy moth is considered to be more dangerous than European gyspsy moth. According to the these points, North American Plant Protection Organization(NAPPO) take special quarantine measures to Chinese port. It has caused a great disadvantage on Chinese international trading.First, we set different temperature and duration regimes according to the completely random design and quadratic orthogonal regression design. The effects on egg hatch percentage, days to first hatch and hatch duration were recorded. We conclude that Asia gypsy moth need certain period(at least60d) of chilling(lower than5℃) to terminate diapause. But once chilling period is too long eggs may lose incubation vitality and die. Eggs constantly under temperature over20℃are not able to terminate diapause. Secondly, we choose16kinds of tree species to test host selecion suitability which are common in US A or china. Statistics mortality rate, developmental duration and pupae weight to analyze the host impact on Asia gypsy moth. The result showed the larve of AGM feed on Acer saccharum,Betula platyphylla, Populus canadensi could complete life cycle.Larvae feed on Juniperus rigida, Ligustrum lucidum, Buxus megistophylla,Picea koraiensis, Albizia julibrissin, Liriodendron chinense×tulipifera,Pinus bungeana, Pinus massoniana and Pinus thunbergii all died before2nd instar. Larvae feed on P. tabulaeformis, P. strobus and Diospyros kaki after4th instar, mortality is lower than 2nd instar. Once the larve develop after4th instar, host range is wider than1st and2nd instar. In conclusion, on risk analysis of the Asian gypsy moth invasion in North America, the invasion possibility is lower than former estimation of NAPPO.By these conclusions, we can deduce the distribution boundaries of Asian gypsy moth in China. The result shows that HaiNan, Guang Dong, Fu Jian, Guang Xi, south part of Yun Nan and Hu Nan, south west of Jiang Xi province is not suitable for Asia gypsy moth distribution. By the distribution boundaries, we can distinguish some port into safe area. So that limit the economic losses, which caused by NAPPO special quarantine measures.At last, there are two disadvantages in invasion of Asia gypsy moth in North America. It is temperature restraint and host selection restraint. These conclusions may give support to relevant departments when negotiating with NAPPO. So that helping reducing the international trading loss.