化橘红害虫曲牙土天牛生物学特性初步研究

Primary studies on biological characteristics of Dorysthenes hydropicus

目的 了解化橘红基地曲牙土天牛Dorysthenes hydropicus生物学特性，为有效防治提供科学依据。方法：通过田间调查、室内饲养及灯诱了解曲牙土天牛生物学及发生与为害特性。结果：曲牙土天牛在化橘红基地1～2年发生1代，以幼虫在土中越冬；5月下旬为成虫羽化出土盛期。成虫个体差异大，体长25～63cm；趋光性强，1个诱集点每晚可以诱集成虫2000多头；雌成虫抱卵量大，最多达543粒，成虫产卵于1～3cm深土中，卵孵化盛期为6月下旬～7月上旬，孵化率达85％以上，幼虫在15—60cm土层内取食危害。结论：曲牙土天牛在广东危害化橘红、白木香等均为首次报道，对化橘红生产威胁极大，是化橘红基地重点防治对象。

Objective： To study the biological characteristics of Dorysthenes hydropicus in the farm of Cirtus grandis, and offer scientific evidence for prevention and controlling of D. hydropicus. Method： Indoor-rearing and light trap were applied to study the biological characteristics, development course and harmful effect of D. hydropicus. Result： D. hydropicus reproduces one generation in 1-2 year in Guangdong province, and overwinters in the form of larvae. Its imago comes out of the earth mainly in late May after mature. The body length has great individual diversity normally ranged from 25-60 cm, It also shows strong phototaxy. One lamp can trap more than 2 000 of them per night. Female imago has a large egg load with the maximum amount of 543. The eggs hatching is in depth of 1-3 cm soil. The dominant hatching period of egg is from late June to early July, and hatchability is over 85%. The living space of laiva ranges from 15-60 cm in soil. D. hydropicus has caused serious harm and lead to thousands of Cirtus grandis trees death every year. Conclusion ： Dorysthenes hydropicus showed serious threat to the growth of Cirtus grandis and should be prevented and controlled.