饲料害虫的发生规律及防治

COMMUNITY CHARACTERISTICS AND CONTROL OF INSECT PESTS IN THE FODDER OF DOMESTIC ANIMALS

经系统普查，在饲料中发现27种害虫及其天敌。鞘翅目害虫占63．9％，原料仓中优势对为赤拟谷盗、玉米象、谷蠹、亚扁粉盗。生产车间优势种为黑菌虫、赤拟谷盗、玉米象。成品饲料中的优势种为赤拟谷盗、谷蠹、长角扁谷盗、亚扁粉盗。主要害虫高峰期在6～9月。主要优势种的数量随季节变动表现出不连续特点。成品词料初期害虫竞争性大小为谷蠹＞玉米象；后期害虫竞争性大小为赤拟谷盗＞锯谷盗＞锈赤扁谷盗。饲料抗虫性随饲料颗粒大小而异，颗粒越小，抗虫性越弱。塑料最密封261天的饲料中害虫比未封装的少59．7％。抗虫袋包装饲料可防虫2个月。

Through systematic and general investigation, 27 species of insect Pests and their naturalenemies were found in fodder. The proportion of Coleoptera account for 63.9%. Thedominant species in material warehouse are Tribolium castaneum (Herbst.), Sitophiluszeamais (Motschusky), Rhyzopertha dominica (Fabricius), Palorus subdepressus(Wollaston). The dominant species in workshop are Alphitobius piceus Oliver, T. castaneum(Herbst.), S. zeamais (Motschusky). The dominant species in fodder are T. castaneum(Herbst.), R. dominica (Fabricius ), Cryptolestes minutes Oliver, P. subdepressus(Wollaston).The population density of the main insect pests peaks from June to September, thepopulation quantity of the main dominant species changes discontinuously from season toseason. The order of the competition of initial insect pest in fodder, from high to low, is R.dominica, S. zaeamais, and that of later insect pests is T. castaneum, Oryzaeyhilussurinamensis L., Cryptolestes ferrugineus (Steph). With the pellets of the fodder turningsmaller, the resistance to insect pests decreased. With plastic bags sealing for 261 days, thepopulation quantity of insect pests in fodder decreased 59. 7% than that of uncovered fodder.The resistant - insect bags can keep the fodder from being infested for two months.