蒙古土象的形态和生物学特性研究

Study on the Morphology and Biology ot Xylinophorus mongolicus Faust

蒙古土象主要以成虫为害幼苗,食性杂,为害重。以成虫或幼虫越冬,7月上旬成虫羽化,羽化后在土中蛰伏,翌年4月上旬出蛰,只能爬行。成虫寿命最长390d,一生交配多次,4月下旬开始产卵,卵量444.94±59.5粒,散产于地表层。卵期19～10d。幼虫经17龄,一直在50cm以上土层活动,3年发生1代。

The adult of Xylinophorus Mongolicus Faust which can only crawl is polyphagous and seriously injures the crop seedlings. It overwinters with the state of adult and larva. After its emergence in the middle ten days of June, the adult lives in the upper soil layer until it appears in the first ten days of April the next year and oviposits in the last ten days of April, and may copulate many times throughout its life. The fecundity per female is 70- 905,with an arerage of 509 and the number of eggs laid in each day is 1-35, 1-17 by 82.97% of the femals. The scattered eggs laid in the upper soil layer will hatch in 18-22 days. There are 17 instars in the larval stage. The larva lives under- ground within 50 centimetre of the upper soil. It has one generation in three years.