白蜡虫及其3种优势寄生蜂的时空生态位

在白蜡虫Ericerus pela (Chavannes)分布特征和寄生蜂调查的基础上,分析了白蜡虫及其3种优势寄生蜂:白蜡虫花翅跳小蜂Microterys ericeri Ishii、中华花翅跳小蜂M.sinicus Jiang和白蜡虫阔柄跳小蜂Metaphycus ericeri Xu et Jiang的时间和空间的一维生态位宽度、生态位重叠和比例相似性。结果表明,白蜡虫及其3种优势寄生蜂的时间生态位宽度:白蜡虫>白蜡虫阔柄跳小蜂>白蜡虫花翅跳小蜂>中华花翅跳小蜂,空间生态位宽度:白蜡虫>白蜡虫花翅跳小蜂>白蜡虫阔柄跳小蜂>中华花翅跳小蜂。3种优势寄生蜂与白蜡虫的生态位重叠度:白蜡虫花翅跳小蜂>中华花翅跳小蜂>白蜡虫阔柄跳小蜂,比例相似性:白蜡虫花翅跳小蜂>白蜡虫阔柄跳小蜂>中华花翅跳小蜂。说明白蜡虫花翅跳小蜂与白蜡虫在资源序列上分布的相似性最大,在时间上的同步性和空间上的同域性较强,资源利用程度最高。白蜡虫花翅跳小蜂与白蜡虫阔柄跳小蜂在时间生态位、空间生态位和时间-空间生态位上均有较大的重叠和比例相似性,在资源利用上存在明显的种间竞争。白蜡虫种群数量大,生长周期长、为多种寄生蜂的繁育提供了丰富、稳定的食物资源。

Temporal-spatial niches of Chinese White Wax Scale insect (Ericerus pela) and its three dominant parasitoid wasps

The Chinese white wax scale insect, Ericerus pela (Chavannes), is an important beneficial insect in China which excretes a special wax used as raw material in the chemical industry. The cultivation and utilization of E. pela was has occurred for more than 1000 years in China. Parasitoid wasps are key factors that reduce output of white wax production by E. pela. There are more than 15 species of wasps that parasitize different stages of the life circle of E. pela. The dominant parasitoid wasps are Microterys ericeri Ishii, M. sinicus Jiang, and Metaphycus ericeri Xu et Jiang. The percentage in these wasps was 45.91%, 37.37% and 11.37% respectively. The distribution of parasite wasps is related with distribution of E. pela on host plant. Although many parasitoids (40%) occur in centre of E. pela, about 50% are distributed in the top of host plant. The flight movements of parasitoid wasps is affected by wind and sunlight; wasps in the wind cannot easy fly on top of tree because of their slim and fragile bodies, and wasps tend to like shade and do not like strong sunlight. The temporal-spatial niches (niche breadth, niche overlap and percentage similarity) of E. pela and its dominant parasitoid wasps (Microterys ericeri Ishii, M. sinicus Jiang, and Metaphycus ericeri Xu et Jiang) were analysed base on the investigation of distribution characteristics of E. pela and species of parasite wasps and their active rule. Temporal niche breadths of E. pela and its three dominant parasitoids were E. pela > Metaphycus ericeri > M. ericeri > M. sinicus and spatial niche breadths were E. pela > M. ericeri > Metaphycus ericeri > M. sinicus.The niche overlap of the three dominant parasitoids and E. pela were M. ericeri > M. sinicus > Metaphycus ericeri; the percentage similarities were M. ericeri > Metaphycus ericeri > M. sinicus. This suggests that M. ericeri and E. pela possesses the most similarity in the resources series, strong synchronism and sympatry, and the maximum resource utilization. M. ericeri is the most serious natural enemy of E. pela. M. ericeri and Metaphycus ericeri had a large overlap in temporal-spatial niches and proportion similarity. Interspecific competition for resource utilization between these species was obvious. The species and dynamics of parasitoid wasps depend on biological characteristics of host. The life cycle of E. pela is one year from April to April. E. pela is fecund and one female can reproduce 8000-10000 eggs, but itself lacks a strong capability to defend from natural enemies because its females do not have wings and population can not move after the second instar nymphae live on branches of host plant. E. pela is an abundant and stable food of many parasitoids because of its large population, has poor ability to defend itself and for longer periods, the diversity of temporal and dimensional niche of parasite wasps shows their coevolution skill.