Data from: Does prey encounter and nutrient content affect prey selection in wolf spiders inhabiting Bt cotton fields?

Wolf spiders are abundant and voracious predators at the soil-plant interface in cotton crops. Among other prey, they attack late-instar larvae of the cotton bollworm Helicoverpa spp., an economically important pest. Consequently, wolf spiders in transgenic Bt cotton could provide significant biological control of Bt-resistant Helicoverpa larvae that descend to the soil to pupate. The predator-prey interactions between wolf spiders and Helicoverpa could, however, be constrained by the presence of alternative prey and intraguild predators. This study used laboratory enclosures to analyse the effect of alternative prey on predatory selection of the wolf spider Tasmanicosa leuckartii Thorell. The prey included another wolf spider Hogna crispipes Koch (potential intraguild predator), the ground cricket Teleogryllus commodus Walker (minor pest), and Helicoverpa armigera larvae (major pest). We tested if encounter rates, prey vulnerability, and prey nutritional content influenced the likelihood that a prey was attacked. In three-way food webs, Tasmanicosa encountered and attacked Teleogryllus and Helicoverpa in similar frequencies. However, in the presence of a competing intraguild predator and potential prey (Hogna) in a four-way food web, Tasmanicosa did not always attack Teleogryllus at first encounter, but still attacked Helicoverpa at each encounter. Helicoverpa (protein-poor) and Hogna (protein-rich) were consumed by Tasmanicosa in similar proportions, suggesting that Tasmanicosa might benefit from nutrient balance as an outcome of diverse prey in this food web. As Teleogryllus (protein rich) escapes quicker than Helicoverpa and Hogna, Hogna may be an easier protein-rich option than Teleogryllus. Field surveys showed that while Teleogryllus was the most common prey, wolf spiders feed on diverse insect taxa, as well as other spiders. That Tasmanicosa readily attacked Helicoverpa larvae in the presence of alternative prey is an encouraging result that supports the potential of Tasmanicosa predation to assist in the control of Bt-resistant Helicoverpa larvae and thereby inhibit the proliferation and spread of resistance.

Usage Notes
3_way 4_way food websDescribes characteristics of animals and encounter and predation outcomes in 3-way and 4-way food websLipid and protein analysis dataRaw data on the analysis of protein and lipid contents of arthropods in this food webLipid and protein analysis raw data.xlsxPrey of wolf spiders in cotton fieldsField observations of spider predation in cotton fields

狼蛛作为土壤-植物界面棉田中的丰富且贪婪的捕食者，对多种猎物进行攻击，其中包括棉红铃虫（Helicoverpa spp.）的后期幼虫，该虫种为经济上重要的害虫。因此，转基因Bt棉田中的狼蛛可能对下降至土壤中化蛹的Bt抗性棉红铃虫幼虫提供显著的生物控制。然而，狼蛛与棉红铃虫之间的捕食者-猎物相互作用可能会受到替代猎物和内共生捕食者的存在而受到限制。本研究利用实验室围栏来分析替代猎物对狼蛛Tasmanicosa leuckartii Thorell捕食选择的影响。猎物包括另一种狼蛛Hogna crispipes Koch（潜在的内共生捕食者）、地面蝈蝈Teleogryllus commodus Walker（次要害虫）和棉红铃虫幼虫（主要害虫）。我们测试了遭遇率、猎物易损性和猎物营养含量是否会影响猎物被攻击的可能性。在三重食物网中，Tasmanicosa以相似的频率遭遇并攻击了Teleogryllus和Helicoverpa。然而，在四重食物网中，当存在竞争性内共生捕食者和潜在猎物（Hogna）时，Tasmanicosa在首次遭遇时并不总是攻击Teleogryllus，但仍会在每次遭遇时攻击Helicoverpa。Tasmanicosa以相似的比例消耗了蛋白质含量较低的Helicoverpa和蛋白质含量较高的Hogna，这表明Tasmanicosa可能从这种食物网中多样化的猎物中获益，以实现营养平衡。由于Teleogryllus（蛋白质含量丰富）比Helicoverpa和Hogna逃逸得更快，因此Hogna可能比Teleogryllus更容易成为蛋白质含量丰富的食物来源。实地调查显示，尽管Teleogryllus是最常见的猎物，但狼蛛以多种昆虫类群以及其他蜘蛛为食。Tasmanicosa在存在替代猎物的情况下仍 readily 攻击Helicoverpa幼虫，这一结果令人鼓舞，支持了Tasmanicosa捕食在控制Bt抗性Helicoverpa幼虫方面协助的潜力，从而抑制抗性的扩散。