葡萄牙松材线虫与其媒介昆虫之间的互作

Interactions of the pine wood nematode (Bursaphelenchus xylophilus) with its vector in Portugal

对松材线虫与其在葡萄牙和欧洲的媒介昆虫樟子松墨天牛(Monochamus galloprovincialis)进行了首次研究。在病死木中发现,松材线虫在天牛刚羽化时聚集在蛹室中,线虫主要集中在天牛的后胸部。天牛羽化后6周内,松材线虫主要在天牛成虫补充营养时进入新寄主树,其次在天牛产卵时也会进入寄主树。总的看来,松材线虫在欧洲与其携带天牛之间互作与其在亚洲与松墨天牛及在北美与卡来罗纳墨天牛之间的关系十分相似。经研究,影响线虫与天牛携带关系的因子有内源和外源两类因子,如化学气味和各种信号。但是,其他多数因子尚未了解。研究影响线虫与天牛携带关系的因子将有助于了解两种生物密切关系的内在机制,并有助于研发出新的防控方法。

The most important aspects of the interactions between the pine wood nematode（PWN）（Bursaphelenchus xylophilus） and its local insect vector,the pine sawyer Monochamus galloprovincialis have been recently studied for the first time in Portugal and Europe.Inside the dead pines the pinewood nematode was found to associate with the callow adults in the pupal chambers,just before the insects＇ emergence.The nematodes are more abundant on the thoracic region of the insects,namely on the meta-thorax segment.After emergence,transmission of the PWN into new hosts occurs by the feeding activity of the beetles,being more frequent during the six weeks after emergence.Nematode transmission also occurs by the oviposition activity of the female beetles,although with less frequency and success.Overall,the main aspects of the multiple interactions between B.xylophilus and M.galloprovincialis recently studied in Europe were found to be extremely similar to other well-known interactions of the PWN with other Monochamus vectors worldwide,namely with M.alternatus in Asia and M.carolinensis in North America.The factors that regulate the most important aspects of the nematode-vector phoresis probably result from a complex interaction of endogenous and exogenous factors such as chemical odours and signals.Such factors apparently exert their effect independently of the pine host involved and the Monochamus species vectoring the PWN locally.Nevertheless,despite their importance,these mechanisms and stimuli are mostly unknown and,in general,very poorly understood.A better understanding of such mechanisms could lead to the development of innovative perspectives to disrupt the key moments of the interaction between the two organisms,therefore creating innovative approaches to control the pine wilt disease.