松嫩草地牛粪中大型节肢动物种类组成及种群动态变化

研究并分析了松嫩草地牛粪中大型节肢动物种类组成及动态变化.结果表明,在草地牛粪中共调查到大型节肢动物7目20科43种,以鞘翅目、膜翅目和双翅目为主.依其食性不同,分为粪食性型(8科19种)、腐食性型(4科4种)、植食性型(4科6种)、捕食性型(5科11种)、杂食性型(2科5种)、尸食性型(1科1种)和寄生性型(1科1种).根据鞘翅目金龟总科中营粪食性型生活的粪甲虫对牛粪利用方式的不同,分为外生粪甲虫(6种)、内生粪甲虫(5种)、远生粪甲虫(2种)和偷窃寄生粪甲虫(1种).除了双顶嗡蜣螂,牛粪中大型节肢动物数量与鲜牛粪重量具有显著正相关关系(p＜0.01).粪食性型种类数和个体数量随鲜牛粪堆置时间的延长而迅速减少,7d后消失,其个体总数量与鲜牛粪堆积时间呈显著的负相关关系(p＜0.01),而与牛粪含水量呈显著正相关关系(p＜0.01),各种大型节肢动物因其食性不同在鲜牛粪中占据不同的生态位.鲜牛粪中大型节肢动物以粪食性型占绝对优势,而干牛粪中则以捕食性型和杂食性型为主.牛粪中大型节肢动物种群季节动态变化受温度、降水量与牛粪含水量影响,鲜牛粪中大型节肢动物优势种为直蜉金龟(69.25%)和肖秋家蝇与东方角蝇幼虫(25.12%).4、5、6月份和9月份,优势种为直蜉金龟,7月和8月份,优势种为蝇幼虫.

Composition and seasonal variations of macro arthropod fauna associated with cattle dung pats in Songnen Grassland,China

The species and seasonal variations of macro Arthropod fauna associated with cattle dung pats were studied and analyzed based on the results obtained from field investigation and experiments in Songnen Grassland,China.The result showed that the macro Arthropod fauna associated with cattle dung consisted of 43 species from 19 families,including 32 Coleoptera,4 Hymenoptera,2 Diptera,2 Deramptera,1 Orthoptera,1 Araneae and 1 Acariformes.The macro arthropod fauna included 19 coprophagy species,4 saprophagy species,6 phytophagous species,11 predatism species,5 omnivorey species,1 corpse-eating species and 1 parastitism species according to their feeding habits.The adults of Scarabaeoidea whose feeding habits depended on the liquid in the fresh cattle dung were called dung beetles.There were four contrasting patterns of dung use by dung beetles: 6 species paracoprids,5 species endocoprids,2 species telecoprids and 1 species kleptoparasistes.Statistical analysis showed that except for Onthophagus bivertex,the number of arthropod fauna species of Aphodius restus(Y_1),fly larva(Y_2),Ocypus parvulus(Y_3),Tetramorium caespitum(Y_4) and Total number of arthropod fauna species(Y_5) were all significantly related to the weight of the fresh cattle dung pats(X).The relationships could be fitted into the linearity function,Y_1=6.49X 0.04(R=0.84,p<0.01),Y_2=8.84X-3.20(R=0.87,p<0.01),Y_3=5.20 0.09(R=0.86,p<0.01),Y_4=45.73-12.65(R=0.93 p<0.01),Y_5=74.87X-3.58 (R=0.91,p<0.01) respectively.The species and amount of coprophagy species decreased rapidly,and nearly disappeared after 7 days of fresh cattle dung pats disposition.There was a significantly negative correlation between the amount of coprophagy species(Y) and the days(X_1) after the dung pats disposition in 7 days,and a significantly positive correlation between the amount of coprophagy(Y) and the water content of the cattle dung pats(X_2).The relationships could be fitted into the linearity function,Y=-33.52X_1 146.01(R=-0.95,p<0.01),Y=5.16X_2-237.31(X=0.92,p<0.01).The variations of the different feeding habit species were relative to the dung water content,and it indicated that the arthropod species occupied different niches according to their different feeding habits.The coprophagy species dominated the fresh cattle dung pats,and the predateism and omnivorey species dominated the dry cattle dung pats.The dominant species associated with cattle dung were Aphodius rectus(69.25%) and the fly larvae of Musca amita and Haematobia exigua(25.12%) from April to September. Dung beetles dominated the fresh dung pats in April,May,June and September,the fly larvae of Musca amita and Haematobia exigua dominated the dung pats in July and August.The seasonal variations of dung beetles and the fly larvae of Musca amita and Haematobia exigua were affected by temperature,precipitation and the dung water content.