Otárola-Jiménez Julio, Spehr Richard, Hansson Bill S, Knaden Markus
Department of Evolutionary Neuroethology, Max-Planck Institute for Chemical Ecology, 07745, Jena, Germany.
Chemistry School, University of Costa Rica, San Pedro, San José, 11501- 2060, Costa Rica.
J Chem Ecol. 2025 Jun 20;51(4):67. doi: 10.1007/s10886-025-01620-3.
Female insects possess a complex chemosensory system that enables them to identify optimal oviposition substrates for their developing offspring. Both calorie-rich and protein-rich substrates are particularly attractive for laying eggs. We hypothesize that females detect concentrations of sweet compounds and preferentially select those concentrations that enhance larval survival. To test this, we investigated how female Drosophila melanogaster evaluate substrates with varying concentrations of sugars and amino acids, and whether these preferences correlate with larval survival. Using choice assays, we found that females preferentially deposited eggs on substrates containing 0.1 mol/L sucrose, while higher concentrations (2 mol/L) were consistently avoided-a response not attributable to differences in substrate hardness or prior feeding experience during mating. In contrast, when presented with monosaccharides, females favored intermediate concentrations: 0.5 mol/L for both glucose and fructose, with a marked overall preference for fructose even when combined with an amino acid mixture. Moreover, substrates aligning with the females' oviposition choices often supported best survival of larvae. These findings indicate that female flies assess not only the concentration but might also consider the chemical nature of sweet compounds when making oviposition decisions and they underscore a critical link between maternal site selection and larval development.
雌性昆虫拥有一个复杂的化学感应系统，这使它们能够为发育中的后代识别出最佳的产卵基质。富含卡路里和富含蛋白质的基质对产卵特别有吸引力。我们假设雌性昆虫能够检测甜味化合物的浓度，并优先选择那些能提高幼虫存活率的浓度。为了验证这一点，我们研究了雌性黑腹果蝇如何评估含有不同浓度糖和氨基酸的基质，以及这些偏好是否与幼虫存活率相关。通过选择试验，我们发现雌性果蝇优先将卵产在含有0.1摩尔/升蔗糖的基质上，而较高浓度（2摩尔/升）的蔗糖则一直被避开——这种反应并非归因于基质硬度的差异或交配期间先前的进食经历。相比之下，当面对单糖时，雌性果蝇更喜欢中等浓度：葡萄糖和果糖均为0.5摩尔/升，即使与氨基酸混合物混合时，对果糖也有明显的总体偏好。此外，与雌性果蝇产卵选择一致的基质通常最有利于幼虫存活。这些发现表明，雌性果蝇在做出产卵决定时不仅会评估浓度，还可能会考虑甜味化合物的化学性质，并且它们强调了母体选址与幼虫发育之间的关键联系。
