Roads and traffic have been implicated in population declines in a number of taxonomic groups. However, there is little research into the potential effects of roads or traffic on spiders. Here, we tested the prediction that there would be fewer aerially-dispersing (i.e., ballooning) spiders at high-traffic than low-traffic roads. We used custom-made sticky traps attached to a vehicle to collect ballooning spiders along 10 high-traffic–low-traffic rural road pairs in southeastern Ontario, Canada. We collected half as many spiders at high-traffic than low-traffic roads. This provides the first published evidence of negative traffic effects on ballooning spiders. Although consistent with our prediction that ballooning spiders are less abundant at high-traffic roads, there are several possible explanations for this finding. Further study is needed to investigate these explanations, including whether the observed traffic effect reflects reduced population sizes near high-traffic roads or reduced ballooning behaviour near high-traffic roads. If the former, then roads may represent a significant conservation concern for ballooning spider species.

道路和交通已牵涉到许多生物分类人群的减少。但是，关于道路或交通对蜘蛛的潜在影响的研究很少。在这里，我们测试了这样的预测：高流量的道路上的空中分散蜘蛛（即气球）比低流量的道路上的蜘蛛要少。我们使用了附着在车辆上的定制粘性诱集装置，沿着加拿大安大略省东南部的10条交通拥挤的交通路况收集了通行蜘蛛。我们在高流量的道路上收集的蜘蛛是低流量的道路的一半。这提供了第一个已公开的证据，表明对热气球产生不利的交通影响。尽管与我们的预测一致，即在交通拥挤的道路上，热气球的数量较少，但对此发现有几种可能的解释。需要进一步研究以研究这些解释，包括观察到的交通影响是否反映出在高通行道路附近人口减少或在高通行道路附近气球交通减少。如果是前者，那么道路可能代表着对不断膨胀的蜘蛛物种的重大关注。