2009年1代草地螟将为我国发生最重的世代

本文通过对草地螟(Loxostege sticticalis)发生危害规律、2009年1代幼虫的虫源数量以及温湿条件可能变化趋势的分析，对我国2009年1代幼虫的发生危害程度进行了预测。2009年1代幼虫的有效虫源面积为600万hm2，总量为43 022亿头，为2004年1代幼虫虫源数量的113倍。为此，预测2009年1代幼虫的发生危害面积将超过1 100万hm2，为历年历代最重。到时将有430万亿头幼虫危害，如不防治，将有2.15亿t的植物被吃掉。其中以东北和华北地区受害较重。同时还会波及一些与虫源区相邻、但历史上较少发生草地螟危害的地区。东北地区将会出现发生危害早，本地虫源与外来虫源混合发生，受害十分严重的现象。由于越冬成虫的羽化时期长，蛾蜂多、虫态重叠、作物多次受害的现象将十分突出。最后，本文就如何应对2009年1代幼虫大发生，减少草地螟灾害损失进行了讨论。

The first generation of beet webworm, Loxostege sticticalis will be seriously outbreak in Northern China in 2009

The pest status of beet webworm Loxostege sticticalis L. (Lepidoptera: Pyralidae) in northern China are predicted and reported based on analysis of population dynamics, number of hibernating larvae and prevailing weather conditions in the incoming June and July of 2009. The first generation of larval beet webworm will be serious outbreak and areas attacked will exceed 11 million hectares. This prediction is made because the overwintering areas and numbers of larval L. sticticalis found are of 6 millions hectares and 4 302 billions, respectively. Number of the overwintering larvae is 113 times of that found in 2004, which resulted in an outbreak area of 8 million hectares. As a consequence of that, an estimated 215×109 kg of plant material are consumed if they are failed to be controlled. Outbreaks of L. sticticalis will prevail in northern, northeastern and northwestern China but outbreaks in northeastern China will be much earlier and more serious than ever and other regions since many billions of hibernating adults from different source areas will resemble in this area. Areas within 300 km away from the source areas are possibly affected. Overlap of eggs, larvae, pupae and adults is common and crops will be subjected to multiple attacks by the larvae due to lasting of emerging periods and wide distribution of hibernating populations. Tactics and methods to deal with the outbreak of larval beet webworm are finally discussed and suggested.