三角枫上的一种重要害虫——小圆胸小蠹

Euwallacea fornicatus,an important pest insect attacking Acer buergerianum

小圆胸小蠹Euwallacea fornicatus(Eichhoff),异名茶材小蠹或茶枝小蠹,多年来一直危害昆明市翠湖公园的主要行道树三角枫Acer buergerianum,近年来危害加剧,导致主枝枯死甚至全株死亡。该小蠹在昆明地区1 a发生2或3代,以成虫或幼虫在坑道内越冬。越冬成虫于翌年2月开始活动,3月进行交配并产卵于坑道中;4月可见幼虫,幼虫取食坑道中培育的菌丝体,经过5个龄期发育成蛹;6月中旬是第1代幼虫发生高峰期,9月下旬是第2代幼虫发生高峰期;7—9月是成虫出现高峰期。该小蠹虫态重叠现象十分严重,几乎全年可见各种虫态。不同世代之间也有重叠。

Euwallacea fornicatus, with Xyleborus fornicatus as its synonym, has caused severe damage to Acer buergerianum, an important street species in Cuihu Park. In recent years,it is getting more and more serious, and many trees die of it. E. fornicatus has two or three generations a year in Kunming and overwinters as adult or larva in the gallery. The overwintering adults emerge in February the next year, mate and lay eggs in the gallery in March. Larvae appear in April. They feed on the fungal mycelia in the gallery. The larvae have five instars and develop to pupae in the gallery. Most of the first generation larvae appear in mid June, and those of the second generation appear in late September. The emergence peak of the new adults is between July and September. Its stages and generations overlap.