School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia.
PLoS One. 2020 May 29;15(5):e0233653. doi: 10.1371/journal.pone.0233653. eCollection 2020.
Attempts to control invasive species using species-specific pheromones need to incorporate an understanding of interactive effects among those pathways. The larvae of invasive cane toads (Rhinella marina) utilise chemical cues to repulse, attract or suppress conspecific larvae. We can exploit these effects to reduce toad abundance, but the effects of each cue may not be additive. That is, exposure to one type of cue may lessen the impact of exposure to another cue. To assess this possibility, we exposed toad larvae to combinations of cues. Tadpoles that had been exposed to the suppression cue during larval development exhibited no response to the attraction cue, resulting in lower capture rates in attractant-baited traps. Suppression, however, did not affect a tadpole's response to the alarm cue, and exposure to the alarm cue during tadpole development did not affect response to the attraction cue. Tadpoles exposed to the suppression cue were smaller than control tadpoles at 10 days post-exposure, and consequently were more vulnerable to gape-limited invertebrate predators. Our results demonstrate that the responses by toad tadpoles to chemical cues interact in important ways, and are not simply additive when combined. Control efforts need to incorporate an understanding of such interactions if we are to most effectively use chemical-communication pathways to control invasive amphibians.
试图使用物种特异性信息素来控制入侵物种，需要了解这些途径之间的相互作用。入侵的甘蔗蟾蜍（Rhinella marina）幼虫利用化学线索来击退、吸引或抑制同种幼虫。我们可以利用这些效果来减少蟾蜍的数量，但每个线索的效果可能不是相加的。也就是说，暴露于一种类型的线索可能会减轻暴露于另一种线索的影响。为了评估这种可能性，我们将蟾蜍幼虫暴露于各种线索的组合中。在幼虫发育过程中暴露于抑制线索的蝌蚪对吸引线索没有反应，导致在有吸引力的诱饵陷阱中的捕获率降低。然而，抑制作用并不影响蝌蚪对警报线索的反应，而且在蝌蚪发育过程中暴露于警报线索也不会影响对吸引线索的反应。暴露于抑制线索的蝌蚪在暴露后 10 天比对照蝌蚪小，因此更容易受到口器限制的无脊椎捕食者的侵害。我们的研究结果表明，蟾蜍蝌蚪对化学线索的反应以重要的方式相互作用，而不是简单地相加。如果我们要最有效地利用化学通讯途径来控制入侵的两栖动物，那么控制工作就需要了解这种相互作用。
