Marín Linda, Perfecto Ivette
School of Natural Resources and Environment, University of Michigan, Ann Arbor, MI 48109-1041, USA.
Environ Entomol. 2013 Apr;42(2):204-13. doi: 10.1603/EN11223.
Spiders are a very diverse group of invertebrate predators found in agroecosystems and natural systems. However, spider distribution, abundance, and eventually their ecological function in ecosystems can be influenced by abiotic and biotic factors such as agricultural intensification and dominant ants. Here we explore the influence of both agricultural intensification and the dominant arboreal ant Azteca instabilis on the spider community in coffee agroecosystems in southern Mexico. To measure the influence of the arboreal ant Azteca instabilis (F. Smith) on the spider community inhabiting the coffee layer of coffee agroecosystems, spiders were collected from coffee plants that were and were not patrolled by the ant in sites differing in agricultural intensification. For 2008, generalized linear mixed models showed that spider diversity was affected positively by agricultural intensification but not by the ant. However, results suggested that some spider species were associated with A. instabilis. Therefore, in 2009 we concentrated our research on the effect of A. instabilis on spider diversity and composition. For 2009, generalized linear mixed models show that spider richness and abundance per plant were significantly higher in the presence of A. instabilis. In addition, analyses of visual counts of insects and sticky traps data show that more resources were present in plants patrolled by the ant. The positive effect of A. instabilis on spiders seems to be caused by at least two mechanisms: high abundance of insects and protection against predators.
蜘蛛是一类非常多样的无脊椎动物捕食者，存在于农业生态系统和自然系统中。然而，蜘蛛在生态系统中的分布、数量以及最终的生态功能可能会受到非生物和生物因素的影响，如农业集约化和优势蚂蚁。在这里，我们探讨了农业集约化和优势树栖蚂蚁不稳定阿兹特克蚁对墨西哥南部咖啡农业生态系统中蜘蛛群落的影响。为了衡量树栖蚂蚁不稳定阿兹特克蚁（F. 史密斯）对栖息在咖啡农业生态系统咖啡层的蜘蛛群落的影响，在农业集约化程度不同的地点，从有蚂蚁巡逻和没有蚂蚁巡逻的咖啡植株上收集蜘蛛。对于2008年，广义线性混合模型表明，蜘蛛多样性受到农业集约化的积极影响，但不受蚂蚁的影响。然而，结果表明一些蜘蛛物种与不稳定阿兹特克蚁有关联。因此，在2009年，我们将研究重点集中在不稳定阿兹特克蚁对蜘蛛多样性和组成的影响上。对于2009年，广义线性混合模型表明，在有不稳定阿兹特克蚁存在的情况下，每株植物上的蜘蛛丰富度和数量显著更高。此外，对昆虫的目视计数和粘性陷阱数据的分析表明，在有蚂蚁巡逻的植株上有更多的资源。不稳定阿兹特克蚁对蜘蛛的积极影响似乎至少由两种机制引起：昆虫数量多以及抵御捕食者。
