Data from: Toxicity and utilization of chemical weapons: does toxicity and venom utilization contribute to the formation of species communities?

Toxicity and the utilization of venom are essential features in the ecology of many animal species and have been hypothesized to be important factors contributing to the assembly of communities through competitive interactions. Ants of the genus Monomorium utilize a variety of venom compositions, which have been reported to give them a competitive advantage. Here, we investigate two pairs of Monomorium species, which differ in the structural compositions of their venom and their co-occurrence patterns with the invasive Argentine ant. We looked at the effects of Monomorium venom toxicity, venom utilization, and aggressive physical interactions on Monomorium and Argentine ant survival rates during arena trials. The venom toxicity of the two species co-occurring with the invasive Argentine ants was found to be significantly higher than the toxicity of the two species which do not. There was no correlation between venom toxicity and Monomorium survival; however, three of the four Monomorium species displayed significant variability in their venom usage which was associated with the number of Argentine ant workers encountered during trials. Average Monomorium mortality varied significantly between species, and in Monomorium smithii and Monomorium antipodum, aggressive interactions with Argentine ants had a significant negative effect on their mortality. Our study demonstrates that different factors and strategies can contribute to the ability of a species to withstand the pressure of a dominant invader at high abundance, and venom chemistry appears to be only one of several strategies utilized.

毒性与毒液利用是诸多动物物种生态学中的核心特征，且被假说为通过种间竞争作用调控群落组装的关键因素。小家蚁属（Monomorium）蚂蚁拥有多样的毒液组分，相关研究表明这类组分可赋予其竞争优势。本研究针对两对小家蚁属物种展开探究，二者在毒液结构组成以及与入侵阿根廷蚁（Argentine ant）的共存模式上存在差异。我们通过人工竞技场试验（arena trials），探究了小家蚁属毒液毒性、毒液利用模式以及攻击性物理互作，对小家蚁属蚂蚁与阿根廷蚁存活率的影响。研究发现，与入侵阿根廷蚁共存的两个小家蚁属物种，其毒液毒性显著高于未与之共存的两个物种。毒液毒性与小家蚁属蚂蚁存活率之间未呈现显著相关性；然而，四个小家蚁属物种中的三个在毒液使用上表现出显著变异性，且该变异性与试验中遭遇的阿根廷蚁工蚁数量相关。不同小家蚁属物种的平均死亡率存在显著差异；其中，史密斯小家蚁（Monomorium smithii）与反足小家蚁（Monomorium antipodum）与阿根廷蚁的攻击性互作，对其死亡率产生了显著的负面影响。本研究表明，不同的因子与策略可共同助力物种应对高丰度优势入侵者的生存压力，而毒液化学组分仅为其所利用的多种策略之一。