新收获小麦中玉米象发生及虫蚀粒率变化研究

SITOPHILUS ZEAMAIS(MOTSCHULSKY) ADULT EMERGENCE AND CHANGES IN PERCENTAGE OF INSECT DAMAGED KERNEL IN NEW HARVESTED WHEAT

了解田间收获小麦中储粮害虫的发生和危害情况,是进行科学防治和避免或减少损失的基础。在防止后期害虫感染的前提下,从田间收获的水分含量为9.9%的泛麦8号(河南省漯河市田间采集)、水分含量为11.6%的郑麦7698(河南省濮阳市田间采集)和水分含量为13.2%的济麦22(山东省德州市田间采集)3个品种,在保持原始水分和适宜温度(25℃)的条件下,研究了不同时间的害虫发生与虫蚀粒率变化情况。主要结果为:泛麦8号在储存前期的120 d里样品中未检出玉米象成虫,150 d后样品中成虫密度达1.3头/kg,270 d后样品中成虫密度达1.7头/kg,经过240 d的储存后样品的虫蚀粒率一直为0%。郑麦7698储存45 d后样品中玉米象成虫密度为2.0头/kg,此时小麦的虫蚀粒率为0%;270 d后样品中的成虫密度达2.7头/kg,粮食的虫蚀粒率增至3.0%。济麦22储存45 d后样品的害虫密度为5.3头/kg,虫蚀粒率为0%;75 d后样品的害虫密度为57头/kg,虫蚀粒率为0.4%;270 d后样品的害虫密度达320头/kg,虫蚀粒率为7.4%。结果表明:收获后水分含量从9.9%至13.2%的3个小麦品种在田间均可感染玉米象;隐藏于籽粒内的玉米象虫卵在后期储存中羽化为成虫的时间与数量受小麦水分含量影响显著,水分含量低的小麦样品中玉米象发育至成虫的时间明显滞后且数量少;收获后储存中小麦样品虫蚀粒率的增加与其水分含量、害虫发育时间以及害虫数量密切相关。

Understanding grain pest occurrence and its harmful situationin new harvested wheat from field is the basis of scientific prevention and treatment and to avoid or reduce losses. Sitophilus zeamais（Mostchulsky） is easy to occurrence in variety of storage materials such as corn,rice and wheat,resulting in the serious decline infood quality. The adult density（adult/kg grain）emergence and insect damaged kernel（IDK） percentage of three strains of new harvest wheat were measured in the present study. Three strains of wheat included Fanmai8 collected from Luohe of Henan Province with 9.9% of moisture content,Zhengmai 7698 from Puyang of Henan Province with 11.6% m.c. and Jimai 22 from Dezhou of Shandong Province with 13.2% m.c.All wheat samples were kept the initial moisture content and were directly stored under 25 ℃ in chamber without infestation. The results showed that the insect density in the sample of Fanmai8 was 0 adult/kg after 120 d storage,1.3 adult/kg after 150 d and 1.7 adult/kg after 270 d. The IDK was 0% after 240 d storage duration. The insect density and IDK of Zhengmai 7698 sample were 2.0 adult/kg and 0% after 45 d,which were increased to 2.7 adult/kg and3.0% after 270 d,respectively. The insect density and IDK of strain Jimai 22 were 5.3 adult/kg and 0% after 45 d,57 adult/kg and 0.4% after 75 d and 320.0 adult/kg and 7.4% after 270 d respectively. The results indicated that the three strains of wheat with moisture content of 9.9% to 13.2% all could be infected by maize weevil before harvest in the field. The Sitophilus zeamaisadult emergence numbers and time from insect eggs hidden in the kernels were sharply affected by the moisture content of wheat,and the insect developed in longer time and emerged in less number in lower moisture content of wheat. The percentage of IDK was closely correlated with wheat moisture content,adult emergence time and numbers.