Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 1Z4 Canada.
Ecology. 2013 Feb;94(2):537-43. doi: 10.1890/12-0030.1.
Examining community-wide patterns for the most diverse animal group, insects, is fundamental to our understanding of the ecological and evolutionary factors that maintain tropical diversity. Using several sampling techniques (malaise traps, pitfall traps, visual searches, and social spider nest captures), we investigated the day-night community composition of active insects to reveal differences in body size at three elevations in eastern Ecuador. We show that insects active at night are, on average, larger than those active during the day. Even though insect size decreased with increasing elevation, the observed diel pattern was consistent across elevations, and for most insect orders. All sampling techniques consistently detected day--night differences in insect size, except for social spider captures at the two higher elevations, probably due to the reduced range of colony sizes at the higher elevations and possibly lower spider activity at night. We suggest that the observed diel patterns in insect size may be driven by a combination of factors, including increased risk imposed on large insects by diurnal visual predators, mainly insectivorous birds, and physiological responses to diel changes in abiotic conditions.
研究昆虫这一最为多样化的动物群体的社区模式，对于我们理解维持热带生物多样性的生态和进化因素至关重要。本研究采用多种采样技术（诱虫灯陷阱、陷阱、目视搜索和社会性蜘蛛巢捕获），调查了厄瓜多尔东部三个海拔高度的活跃昆虫的日夜群落组成，以揭示体型大小的差异。结果表明，夜间活动的昆虫平均比白天活动的昆虫体型更大。尽管昆虫的体型随着海拔的升高而减小，但昼夜模式在各个海拔高度和大多数昆虫目都保持一致。除了在两个较高海拔的社会性蜘蛛捕获外，所有采样技术都一致检测到了昆虫体型的昼夜差异，这可能是由于较高海拔的巢群大小范围缩小以及蜘蛛夜间活动可能减少所致。我们认为，昆虫体型的昼夜模式可能是由多种因素共同驱动的，包括昼间视觉捕食者（主要是食虫鸟类）对大型昆虫的风险增加，以及对昼夜生境条件变化的生理响应。
