The natural habitat of Drosophila melanogaster Meigen (Diptera: Drosophilidae) is fermenting fruits, which can be rich in ethanol. For unknown reasons, temperate populations of this cosmopolitan species have higher ethanol resistance than tropical populations. To determine whether this difference is accompanied by a parallel difference in preference for ethanol, we compared two European and two tropical African populations in feeding and oviposition preference for ethanol‐supplemented medium. Although females of all populations laid significantly more eggs on medium with ethanol than on control medium, preference of European females for ethanol increased as ethanol concentration increased from 2 to 6%, whereas that of African females decreased. In feeding tests, African females preferred control medium over medium with 4% ethanol, whereas European females showed no preference. Males of all populations strongly preferred control medium. The combination of preference for ethanol in oviposition, and avoidance or neutrality in feeding, gives evidence that adults choose breeding sites with ethanol for the benefit of larvae, rather than for their own benefit. The stronger oviposition preference for ethanol of temperate than tropical females suggests that this benefit may be more important in temperate populations. Two possible benefits of ethanol for which there is some experimental evidence are cryoprotection and protection against natural enemies.

中文翻译：

---

黑腹果蝇温带和热带种群在摄食和产卵中对乙醇的偏好

黑腹果蝇（Drosophila melanogaster Meigen）（双翅目：果蝇科）的自然栖息地是发酵果实，可富含乙醇。由于未知原因，这种世界性物种的温带种群比热带种群具有更高的乙醇耐受性。为了确定这种差异是否伴随着对乙醇偏好的平行差异，我们比较了两个欧洲和两个热带非洲种群对乙醇补充培养基的摄食和产卵偏好。尽管所有种群的雌性在含乙醇的培养基上产卵明显多于对照培养基，但随着乙醇浓度从 2% 增加到 6%，欧洲雌性对乙醇的偏好增加，而非洲雌性则下降。在饲养试验中，非洲雌性比含 4% 乙醇的培养基更喜欢对照培养基，而欧洲女性则没有表现出偏好。所有种群的雄性都强烈偏好对照培养基。产卵时对乙醇的偏好，以及在喂养时避免或中性，证明成虫选择乙醇繁殖地是为了幼虫的利益，而不是为了自己的利益。温带雌性对乙醇的产卵偏好强于热带雌性，这表明这种益处在温带种群中可能更为重要。有一些实验证据表明乙醇的两个可能的好处是冷冻保护和防止天敌。提供证据表明，成年人选择有乙醇的繁殖地是为了幼虫的利益，而不是为了自己的利益。温带雌性对乙醇的产卵偏好强于热带雌性，这表明这种益处在温带种群中可能更为重要。有一些实验证据表明乙醇的两个可能的好处是冷冻保护和防止天敌。提供证据表明，成年人选择有乙醇的繁殖地是为了幼虫的利益，而不是为了自己的利益。温带雌性对乙醇的产卵偏好强于热带雌性，这表明这种益处在温带种群中可能更为重要。有一些实验证据表明乙醇的两个可能的好处是冷冻保护和防止天敌。