松墨天牛生物学特性的研究

Study on the Biological Characteristic of Monochamus Alternatus Hope

松墨天牛在福建闽北1a发生1代,以3～5龄幼虫在蛀道内越冬,极少数以低龄幼虫在树皮下越冬。4月上旬越冬幼虫在木质部内做一椭圆形蛹室化蛹,历时13～15d后成虫羽化。羽化后的成虫从蛹室向外咬圆形的羽化孔道飞出,6月上中旬是成虫羽化出孔的高峰期。成虫的雌雄性比为1∶1。在林间,成虫寻找松树嫩枝树皮补充营养,5～9d后开始交尾产卵,产卵前在树皮上咬刻槽,造成泪滴状松脂流下,1刻槽产卵1粒,少数可产2～4粒。卵期6～10d。幼虫孵化后取食松树内皮和韧皮部,在树皮外可见白色纤维状或褐色粉末状木屑与粪便的混合物。3龄幼虫咬一长椭圆形蛀入孔进入木质部,此后树皮外不再出现蛀屑。幼虫在蛀入木质部前死亡率极高,只有31 68%能蛀入树干中,幼虫期易受白僵菌侵染。幼虫期260～310d。

Monochamus alternatus Hope occurred one generation in Wuyishan,Fujian,overwintering as 3～5instar larvae in boring tunnel,still a few low instar larvae in the bark.In the first April,the overwintering larva makes a oval papal chamber in xylem.After 13～15 days,the adult emerges.The adult snaps a circular eclosion hole from the pupal chamber to fly out.The amount of adults occur a peak in last May to first June.The female and male is 1 vs.1.In forest,the adults look for spear extra-nutrition.After 5～9 days they mate and lay the eggs in gap they gnawed.On the pine bark there are some teadrop-like pine resin flowing down for oviposition.Usually one egg is laid on a gap,few 2～4 eggs.The eggs last 6～10 days.The larvae feed on the bark inside and phloem after hatched and discharge the mixture composed with white fiber,brown power and feces to the bark.3-instars bite a elongated oval boring hole to xylem,then the mixture disappear.Only 31.68% of the larvae can bore into xylem for the high mortality.The larvae are easy infested by Beauveria bassiana.The larvae last 260～310 days.