Citrus Research and Education Center, IFAS, University of Florida, Lake Alfred, FL, United States of America.
School of Forestry & Environmental studies, Yale University, 195 Prospect, New Haven, CT, United States of America.
PLoS One. 2018 Oct 8;13(10):e0204984. doi: 10.1371/journal.pone.0204984. eCollection 2018.
Aphids are an attractive food source to many predators and parasitoids because of their small size, soft bodies and slow movement. To combat predation, aphids evolved both behavioral and chemical defensive mechanisms that are operated via siphunculi (cornicles), differently developed structures that more or less extend from their abdomen. Although both direct and indirect linkages between siphunculi and their defensive mechanisms have been explored, their ultimate effects on aphid fitness are still broadly debated. To explicitly test the influence of siphunculi on brown citrus aphid, Aphis (Toxoptera) citricida (Kirkaldy), fitness, we razor-cut and laser-sealed the siphunculi. Siphunculi removal resulted in two distinct behavior modifications, (false aggregation and increased drop-off rates) that led to decreased survival and the loss of the ability to right themselves from an inverted position. These results together indicate that siphunculi play an important role in survival, and removal of these organs will have negative effect on aphid fitness. Furthermore, results suggested that released alarm pheromone may play an important role in communication among aphid clone-mate, and omitting it results in miscommunication and competition among clonemates. These findings will help in better understanding the aphid biology.
蚜虫由于体型小、身体柔软、行动缓慢，成为许多捕食者和寄生蜂的理想食物来源。为了抵御捕食，蚜虫进化出了行为和化学防御机制，这些机制通过触角（喙）来操作，触角是从腹部或多或少延伸出来的不同发育结构。尽管触角及其防御机制之间的直接和间接联系已经被探索过，但它们对蚜虫适应性的最终影响仍存在广泛争议。为了明确测试触角对棕色柑橘蚜（Aphis（Toxoptera）citricida（Kirkaldy））适应性的影响，我们使用剃刀切割和激光密封的方法来切除触角。触角的去除导致了两种明显的行为改变（虚假聚集和脱落率增加），从而导致生存率降低，并且失去了从倒置位置自行恢复的能力。这些结果共同表明，触角在生存中起着重要作用，去除这些器官会对蚜虫的适应性产生负面影响。此外，结果表明，释放的报警信息素可能在蚜虫克隆同体色群体之间的交流中发挥重要作用，而省略它会导致克隆同体色之间的信息错误传递和竞争。这些发现将有助于更好地理解蚜虫的生物学。
