中国亚热带森林筑巢独栖蜂类群及其寄生者多样性

Diversity of cavity-nesting Hymenoptera and their parasitoids in subtropical forests,southeastern China

筑巢独栖蜂包括捕食者和传粉者,在生态系统中具有重要的生态功能。巢管法用于研究筑巢蜂的生物学、生活史、多样性和生态学特性,但此前较少用于研究亚热带森林中的独栖蜂。经过在生物多样性-生态系统功能实验(BEF-China)新岗山样地5年的长期定点监测和实验样本积累,我们发现了独栖蜂的主要类群和发生规律。巢管法共获得128个物种,隶属于3目25科。其中传粉者占全部独栖蜂的26.6%,共2科12种,主要为分舌蜂和切叶蜂;捕食者约占全部独栖蜂的73.4%,有4科44种,以蜾蠃、蛛蜂、泥蜂和方头泥蜂为主;独栖蜂寄生者有19科72种,主要类群是麻蝇、蜂虻、青蜂、钩腹蜂和姬小蜂。独栖蜂物种组成中传粉者多样性显著低于捕食者。同时独栖蜂中普遍存在着雌雄羽化异律现象,即雄性先羽化,并在越冬个体中更明显。切叶蜂科和方头泥蜂科的发生时间比蜾蠃亚科和蛛蜂科的发生时间更集中。此外,通过构建独栖蜂及其寄生者的互作网络,我们发现寄生者多度和多样性受较低营养级寄主的上行控制效应调节。上述结果揭示了对中国亚热带森林地区独栖蜂及其寄生者多样性,有利于更好地保护野生独栖蜂资源,发挥其生态服务功能。

Backgruound&Aims:Cavity-nesting Hymenoptera are both predators and pollinators and provide key services for ecosystem functioning.Previously,there have been few studies on cavity-nesting Hymenoptera in subtropical forests.Yet this study aims to better understand the diversity and biology of cavity-nesting Hymenopterans in subtropical forest in China.Methods:Trap nests were used to study the biology,life history,diversity and ecology of solitary bees and wasps.We used this method to collect cavity-nesting Hymenoptera in 88 plots.Based on five years of long-term monitoring and sampling on Biodiversity-Ecosystem Functioning Experiment China(BEF-China)platform,we recorded the species diversity of cavity-nesting Hymenoptera and relevant occurrence patterns of solitary bees and wasps.Results:We found 3 orders,25 families and 128 species in the trap nest system.Pollinators accounted for 26.6%of the diversity,mainly including Colletidae and Megachilidae with 12 species in 2 families.Predators represented 73.4%of the diversity,mainly including Eumeninae,Sphecidae,Pompilidae and Crabronidae with 44 species in 4 families.There were 72 species of parasitoids in 19 families,mainly including Sarcophagidae,Bombyliidae,Chrysididae,Trigonalyidae,and Eulophidae.Conclusion:For species composition,we found the diversity of pollinators was significantly less than that of predators.Meanwhile,we noted the protandry was common in cavity-nesting Hymenoptera and more obvious in overwintering individuals.In addition,we also found variable occurrence patterns in different species.The occurrence time of Megachilidae and Crabronidae were more concentrated than that of Eumeninae and Pompilidae.Finally,by constructing the interaction relationship between host and parasitoids,we explained the abundance and richness of parasitoids to be regulated by the bottom-up effect of lower trophic hosts.Ultimately,a greater understanding of these organisms will help to better protect the resources wild cavity-nesting Hymenoptera use for their ecological services.