摘要
生物体的外在形态(个体大小及异速生长)不仅是分类学的重要依据,也是影响生物与环境相互作用的重要功能性状。昆虫体型的地理分异及其机制是昆虫生物地理学的重要基础。本文基于中国省级行政区的瓢虫体型、分布和环境因子数据,运用相关和回归分析,探索了中国瓢虫体型(体长、体宽与长宽比)的纬度地带性及其与环境因子的关系。为了确定营养级对瓢虫体型特征的影响,我们对全部瓢虫、植食性瓢虫和捕食性瓢虫分别进行分析。研究结果表明:(1)瓢虫的体型大小具有显著的纬度地带性,即纬度越高,瓢虫的体长或体宽越大,符合贝格曼法则。与温度相关的环境因子是导致瓢虫体型大小地理分异的主要环境因素,因为瓢虫以成虫越冬,体型越大则能量储存越多,冬眠期间的耐饥力越强;(2)由于食性和食物空间分布的差异,在各个纬度上,植食性瓢虫体型总是大于捕食性瓢虫;捕食性瓢虫的长宽比与纬度呈显著正相关,即纬度越高,瓢虫体型越狭长;而植食性瓢虫的长宽比与纬度没有显著的相关性;捕食性瓢虫的长宽比与年降水量呈显著负相关,因为年降水量降低导致植被的斑块化增加,引起捕食对象分布更为分散,从而要求瓢虫具有更强的飞行能力,即更大的长宽比。综上所述,在省级尺度上,温度和降水分别主要影响瓢虫的大小和长宽比,其效应随营养级(食性)的变化而变化。
The extent shape of organisms （body size and the allometry of specific parts） is not only the base for taxonomy, but also the key functional traits for understanding the interaction between organisms and en- vironmental conditions. The geographical variance of body size, allometry, and the underlying mechanisms are fundamental for insect biogeography, but have not been fully documented. In this paper, we compiled da- ta on body size （body length and body width）, aspect ratio （body length/body width）, and distribution of la- dybirds in 28 provinces in China. Meanwhile, we obtained environmental variables representing temperature and precipitation from freely available data. To explore the spatial variance and environmental correlates of body size and aspect ratio in different species groups with various trophic positions, correlation and regres- sion analyses were performed separately on herbivorous and predaceous ladybirds. Our results show that there is evident latitudinal gradient for body size of ladybirds, i.e., body length or width increases with in- creasing latitude. This is consistent with Bergmann＇s rule. Temperature-related variables are the main drivers of geographic variance of body size, because ladybirds usually overwinter as adults, and those with larger body size have more fat and therefore are more resistant to starvation in winter. Herbivorous ladybirds are always larger than predaceous ladybirds in terms of body length and width along the latitudinal gradients. This is due to discrepancies in food and nitrogen concentrations, with predaceous ladybirds having higher ni- trogen concentrations than herbivorous ladybirds. Aspect ratio increases significantly with latitude for preda- ceous ladybirds, but not for herbivorous ladybirds. This may be explained by the high spatial dispersion of prey for predaceous ladybirds, which are further influenced by their own host plants. The most important en- vironmental variables controlling geographic variance in aspect ratio of predaceous ladyb
出处
《生物多样性》
CAS
CSCD
北大核心
2015年第6期775-783,共9页
Biodiversity Science
基金
国家科技支撑计划(2012BAC01B08)
国家环境保护公益性行业科研专项(201409055)
关键词
瓢虫
体型
环境因子
体长
体宽
长宽比
ladybirds, body size, environmental factor, body length, body width, aspect ratio
