CHU Lille, EA 7367 - UTML - Unite de Taphonomie Medico-Legale, University of Lille, 59000, Lille, France.
Sci Rep. 2018 Feb 12;8(1):2844. doi: 10.1038/s41598-018-21316-x.
Necrophagous Calliphoridae breed in vertebrate carrion. Their larvae aggregate and form large masses of individuals. These aggregated larvae can reach adulthood faster than scattered larvae, increasing their chances of survival. Furthermore, the gathering of larvae of different species suggests possible interspecific aggregation vectors. In this context, the effect of larval ground-left cues on larvae of Calliphora vomitoria and Lucilia sericata was studied. We used video tracking to follow larvae placed in binary choice tests. We observed (1) a preference of both species for a side marked by conspecific or heterospecific larvae compared to an unmarked side, (2) a preference of L. sericata larvae for a conspecific-marked side compared to a heterospecific-marked side but only at high concentration of cues and (3) a preference of both species for the side marked by the greater number of larvae. These results demonstrate that larvae leave a mark locally which is retentive, has an interspecific range, has an effect proportional to its intensity and whose strength varies depending on the emitting species. According to the self-organization theory, this mark could enhance larval gathering and promote interspecific aggregations. While not yet demonstrated, an interspecific Allee effect could explain the interspecific association of necrophagous calliphorid larvae.
食腐性丽蝇科的幼虫在脊椎动物尸体中繁殖。它们的幼虫聚集并形成大量个体。这些聚集的幼虫比分散的幼虫更快地达到成年期，从而增加了它们的生存机会。此外，不同物种幼虫的聚集表明可能存在种间聚集的媒介。在这种情况下，研究了幼虫留下的地面痕迹对丽蝇和丝光绿蝇幼虫的影响。我们使用视频跟踪来跟踪放置在二元选择测试中的幼虫。我们观察到：（1）与未标记侧相比，两种幼虫都更喜欢标记有同种或异种幼虫的一侧；（2）与标记有异种幼虫的一侧相比，L. sericata 幼虫更喜欢标记有同种幼虫的一侧，但仅在高浓度线索时才会出现这种情况；（3）两种幼虫都更喜欢标记有更多幼虫的一侧。这些结果表明，幼虫会在局部留下一种有保留性的、具有种间范围的标记，其强度与强度成正比，而其强度取决于释放物种。根据自组织理论，这种标记可以促进幼虫的聚集，并促进种间聚集。虽然尚未得到证实，但种间阿利效应可以解释食腐性丽蝇科幼虫的种间关联。
