赤松梢斑螟在藏东南高山松上的生物学特性

Biological characteristics of Dioryctria sylvestrella on Pinus densata in Southeast Tibet

【目的】研究赤松梢斑螟(Dioryctria sylvestrella(Ratzeburg))在藏东南高山松上的生物学特性,为监测和防治该害虫提供理论依据。【方法】在藏东南选择4块有代表性的高山松林进行野外观察,每7 d从观察林地采集5个有虫球果于室内解剖,测量其中的赤松梢斑螟幼虫形态指标;然后将赤松梢斑螟幼虫饲养在室外水培枝高山松球果中,观察其取食、结茧、羽化、交配、产卵、孵化、越冬等生物学特性。【结果】赤松梢斑螟成虫雌雄同型,体长13~17 mm,翅展23~28 mm;老熟幼虫体长约12 mm,头宽约2.5 mm,头部黑褐色、有光泽;初龄幼虫乳白色,后渐变为淡红色,腹足趾钩单序环式,臀足趾钩双序缺环式;卵呈卵圆形,黄白色;蛹体长约13 mm,宽约3.5 mm,尾部有6根臀棘。赤松梢斑螟在藏东南高山松上1年发生1代,以幼虫危害高山松当年生球果并以幼虫越冬,幼虫期约300 d、5龄,蛹期约40 d,成虫期约8 d,卵期约10 d。赤松梢斑螟成虫多数白天上午羽化,次日傍晚交尾,交尾时间长达6~9 h,幼虫一果一虫,无转移危害现象;被害球果畸形,结实不良。【结论】赤松梢斑螟危害高山松球果,成虫和卵阶段在球果外,幼虫和蛹阶段在球果内,有较强隐蔽性。每年6-7月是防治赤松梢斑螟的关键期。

【Objective】 The biological characteristics of Dioryctria sylvestrella(Ratzeburg) on Pinus densata in southeast Tibet were studied to provide basis for monitoring and controlling of the pest.【Method】 Four representative P.densata forest observation bases were selected in southeast Tibet and five larvae were anatomized every 7 days and the morphological index was recorded.Then they were kept in the outdoor hydroponic P. densata cones,and characteristics including feeding,scab,emergence,mating,spawning,hatching,and wintering were observed.【Result】 Adults of D. sylvestrella were sexual isotype,with a body length of 13-17 mm and a wingspan of 23-28 mm.The mature larvae had a body length of about 12 mm and a head width of about 2.5 mm.The head was dark brown and shiny.The larva of the first instar was milky white,and gradually changed to reddish.The crochets from 1 st to 4 th of larvae were single-ordered ring,and its last crochets were double-ordered missing ring.The egg was a yellow-white ovoid in shape.The pupa was about 13 mm long and about 3.5 mm wide,and there were 6 hip spines in the tail.D. sylvestrella occurred one generation per year on P. densata in southeast Tibet.The larvae endangered current year cones of P. densata and overwintered as larvae in cones.The larvae stage was long with 300 days and 5 ages,the pupal stage was about 40 days,the adult stage was about 8 days,and the egg stage was about 10 days.Adults of D. sylvestrella mostly emerged in the morning,mated in the evening of the second day for 6-9 h.There was one insect per fruit without damage metastasis.The damaged cones were malformed and cone production was affected. 【Conclusion】 D. sylvestrella harmed P. densata cones.The adult and egg stages were outside cones,while the larvae and pupa stages were highly concealed in cones.The adult stage from June to July was the key period for prevention and control in southeast Tibet.