Reese Katlynd M, Philpott Stacy M
Department of Environmental Sciences, The University of Toledo, Toledo, OH 43606, USA.
Environ Entomol. 2012 Oct;41(5):1107-14. doi: 10.1603/EN12014.
Phoridae (Diptera) have widespread impacts on insect communities by limiting host ant behavior. However, phorid-ant interactions may vary with habitat or environmental conditions. Three Pseudacteon species parasitize Azteca instabilis Fr. Smith, a common ant in coffee agroecosystems, and limit A. instabilis foraging, indirectly benefiting other insects. However, little is known about how phorid abundance, behavior, and effects change with environmental conditions. In shaded coffee systems, coffee (Coffea arabica L.) grows under a range of shade conditions and management changes affect species interactions. For example, Pseudacteon spp. more strongly limit A. instabilis foraging in low-shade coffee habitats. We sampled relative abundance of three phorid species around A. instabilis nests in three coffee habitats varying in shade management during dry and wet seasons. We measured canopy cover, tree richness, tree density, leaf litter depth, and number of nearby trees with A. instabilis to determine whether these habitat factors correlate with phorid abundance. P. laciniosus Brown was the most abundant phorid in both seasons. Phorid relative abundance did not differ by habitat, but did differ by season. P. laciniosus accounted for a higher proportion of phorids in the wet season (91.4%) than in the dry season (78.9%), and P. planidorsalis Brown accounted for a larger percent in the dry season (21.1%) than in the wet season (7.3%). Phorid composition did not differ with habitat type, and none of the measured environmental variables correlated with changes in phorid composition. Thus, phorids in coffee agroecosystems respond to large seasonal differences, but not differences between coffee habitats.
蚤蝇科（双翅目）通过限制宿主蚂蚁的行为对昆虫群落产生广泛影响。然而，蚤蝇与蚂蚁的相互作用可能会因栖息地或环境条件而异。三种伪蚤蝇属物种寄生于不稳定阿兹特克蚁（阿兹特克蚁是咖啡农业生态系统中的常见蚂蚁），并限制不稳定阿兹特克蚁的觅食行为，从而间接使其他昆虫受益。然而，关于蚤蝇的数量、行为及其影响如何随环境条件变化，我们知之甚少。在遮荫咖啡系统中，咖啡（阿拉伯咖啡）在一系列遮荫条件下生长，管理方式的改变会影响物种间的相互作用。例如，伪蚤蝇属物种在低遮荫咖啡栖息地对不稳定阿兹特克蚁觅食行为的限制作用更强。我们在旱季和雨季对三种遮荫管理方式不同的咖啡栖息地中不稳定阿兹特克蚁巢穴周围的三种蚤蝇物种的相对丰度进行了采样。我们测量了树冠覆盖率、树木丰富度、树木密度、落叶层深度以及附近有不稳定阿兹特克蚁的树木数量，以确定这些栖息地因素是否与蚤蝇的丰度相关。布朗氏伪蚤蝇在两个季节中都是最常见的蚤蝇。蚤蝇的相对丰度在不同栖息地之间没有差异，但在不同季节之间存在差异。布朗氏伪蚤蝇在雨季（91.4%）占蚤蝇的比例高于旱季（78.9%），而平背伪蚤蝇在旱季（21.1%）占的比例高于雨季（7.3%）。蚤蝇的组成在不同栖息地类型之间没有差异，且所测量的环境变量均与蚤蝇组成的变化无关。因此，咖啡农业生态系统中的蚤蝇对季节差异反应明显，但对咖啡栖息地之间的差异没有反应。
