Moreira-Soto Rolando D, Hansson Bill S, Knaden Markus
Department of Evolutionary Neuroethology, Max-Planck Institute for Chemical Ecology, Jena, Germany.
Universidad de Costa Rica, Centro de Investigación en Enfermedades Tropicales, Facultad de Microbiología, San José, Costa Rica.
J Chem Ecol. 2025 Feb 4;51(1):21. doi: 10.1007/s10886-025-01576-4.
Many Drosophila species coexist by sharing their feeding and breeding sites, which may influence their oviposition choices in an interspecies social context. Whether and where to lay eggs is a crucial decision for female flies as it influences the success of their offspring, by minimizing the risk of predation, competition, or cannibalism. Significant gaps exist in our understanding of Drosophila oviposition dynamics in co-occurring species. Here we tested oviposition strategies of Drosophila melanogaster and its close relative Drosophila simulans under different conditions, to assess whether a single female would prefer to oviposit separately or together with another female, be it a conspecific or not. We find that ovipositing females, regardless whether they are conspecifics or not, prefer to oviposit at the same site. This might suggest that the flies regard the benefits of sharing oviposition sites as higher than the potential risks of competition or cannibalism. The willingness to share oviposition sites was lower when the nutritional value of the medium was increased by adding yeast, and was lost when flies were allowed to lay the eggs consecutively, instead of being tested together. The latter might be explained by our additional finding that females become attracted by the presence of other females on oviposition substrates and that this attraction is partly driven by visual cues. Ovipositing in groups might facilitate intra- and interspecific social feeding of same age offspring, as well as enrichment of microbes. However, this cooperation dynamic might change if another female's offspring is already present, as it might be perceived as danger of competition or cannibalism.
许多果蝇物种通过共享取食和繁殖地点而共存，这可能会在种间社会背景下影响它们的产卵选择。对于雌蝇来说，是否以及在哪里产卵是一个至关重要的决定，因为这会影响其后代的生存成功率，能将被捕食、竞争或同类相食的风险降至最低。我们对共存物种中果蝇产卵动态的理解存在重大差距。在这里，我们测试了黑腹果蝇及其近缘种拟果蝇在不同条件下的产卵策略，以评估单个雌蝇是更喜欢单独产卵还是与另一只雌蝇一起产卵，无论这只雌蝇是否为同种。我们发现，产卵的雌蝇，无论它们是否为同种，都更喜欢在同一地点产卵。这可能表明果蝇认为共享产卵地点的好处高于竞争或同类相食的潜在风险。当通过添加酵母提高培养基的营养价值时，共享产卵地点的意愿会降低，而当允许果蝇连续产卵而不是一起测试时，这种意愿就会消失。后者可能可以用我们的另一个发现来解释，即雌蝇会被产卵基质上其他雌蝇的存在所吸引，而且这种吸引部分是由视觉线索驱动的。群体产卵可能会促进同年龄后代的种内和种间社会取食，以及微生物的富集。然而，如果另一只雌蝇的后代已经存在，这种合作动态可能会改变，因为这可能被视为竞争或同类相食的危险。
