木薯主要地下害虫蛴螬、蔗根锯天牛发生规律与防控技术研究

Occurrence Regularity and Control Technology of Cassava Major Soil Insects Grub and Dorysthenes granulosus

为了有效防控木薯地下害虫,笔者就木薯主要地下害虫蛴螬、蔗根锯天牛的发生规律与防控技术进行了研究。结果表明,蛴螬发生一代至少1年,成虫在6～8月雨后羽化出土,高温干旱下,坡地、沙质地及木薯连作地、甘蔗轮作地及花生间套作地受害较重;蔗根锯天牛2～3年发生一代,成虫在4～6月雨后羽化出土,高温干旱下,坡地、沙质地及木薯连作地、甘蔗轮作地受害较重;在种植前选用环保型杀虫剂48%乐斯本乳油1 000倍液和1.8%阿维菌素乳油2 000倍液混合液浸泡种茎5～10 min后种植效果最好,可显著提高出苗率、降低虫害率和提高产量;土坑对金龟子和蔗根锯天牛也具有良好的诱杀效果;"扫虫光"不仅对蔗根锯天牛、蛴螬等木薯主要地下害虫具有良好的防治效果,而且可以促进木薯生长,显著提高鲜薯产量;以种茎药剂处理、土壤药剂处理、土坑诱杀和合理轮作为核心的木薯地下害虫环境友好综合防控效果十分显著,综合防控区平均虫害率由对照的45.6%显著下降到4.2%,产量由对照的16 920 kg/hm2显著提高到49 960 kg/hm2。上述结果为可持续防控木薯害虫的发生与危害提供了理论与技术支撑。

To effectively control cassava soil insects,occurrence regularity and control technology of cassava major soil insects grub and Dorysthenes granulosus were studied.The results showed that,one generation of grub occurred at least 1a,its adults often emergenced in 6～8 months and after raining each year in Hainan and Guangxi.The sloping fields,sandy fields,cassava cropping fields,sugarcane crop rotation fields and peanut intercropping fields were infectee more harmful by grub in the condition of high temperature and drought.One generation of D.granulosus occurred at least 2～3 a,its adults often emergenced in 4～6 months and after raining each year in Hainan and Guangxi.The sloping fields,sandy fields,cassava cropping fields,sugarcane crop rotation fields and peanut intercropping fields were suffered more harmful from D.granulosus in the condition of high temperature and drought.When planting,soaking the stems with the water mixture 48% chlorpyrifos EC 1 000 times and 1.8% mixture of abamectin EC 2 000 times after 5-10 min were to improve significantly germination rate,decrease insect-damage rate and increase production rate.Trapping of pits in soil were very effective to grub and D.granulosus.＂Saochongguang＂ was not only very effective to control grub and D.granulosus,but also promoted the development of cassava plants and increase production.Furthermore,integrated control technology of soaking the stems,trapping of pits in soil,soil treatment with insecticide and reasonable rotation was very effective to control grub and D.granulosus,insect-damage rate significantly decreased from 45.6% of CK to 4.2% and its production significantly increased from 16.92 ton/ha to 49.96 ton/ha.The results above will be much helpful to sustainable control cassava pests.