Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa
Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield 0028, South Africa.
J Exp Biol. 2019 Mar 27;222(Pt 6):jeb192534. doi: 10.1242/jeb.192534.
Adult holometabolous insects may derive metabolic resources from either larval or adult feeding, but little is known of whether adult diets can compensate for deficiencies in the larval diet in terms of stress resistance. We investigated how stress resistance is affected and compensated for by diet across life stages in the marula fruit fly (Diptera: Tephritidae). Larvae were fed diets containing either 8% torula yeast, the standard diet used to rear this species, or 1% yeast (low protein content similar to known host fruit). At emergence, adults from each larval diet were tested for initial mass, water content, body composition, and desiccation and starvation resistance or they were allocated to one of two adult diet treatments: sucrose only, or sucrose and yeast hydrolysate. The same assays were then repeated after 10 days of adult feeding. Development on a low protein larval diet led to lower body mass and improved desiccation and starvation resistance in newly emerged adults, even though adults from the high protein larval diet had the highest water content. Adult feeding decreased desiccation or starvation resistance, regardless of the diet provided. Irrespective of larval diet history, newly emerged, unfed adults had significantly higher dehydration tolerance than those that were fed. Lipid reserves played a role in starvation resistance. There was no evidence for metabolic water from stored nutrients extending desiccation resistance. Our findings show the possibility of a nutrient-poor larval environment leading to correlated improvement in adult performance, at least in the short term.
成年完全变态昆虫可以从幼虫或成虫取食中获得代谢资源，但对于成年饮食是否可以弥补幼虫饮食在抗应激方面的不足，知之甚少。我们研究了在马鲁拉果蝇（双翅目：瘿蚊科）的生命阶段中，饮食如何影响和补偿抗应激能力。幼虫分别喂食含有 8%的啤酒酵母（用于饲养该物种的标准饮食）或 1%酵母（蛋白质含量低，与已知的宿主果实相似）的饮食。在成虫期，从每种幼虫饮食中取出的成虫进行初始质量、水分含量、身体成分以及脱水和饥饿抗性测试，或者将它们分配到两种成年饮食处理之一：仅蔗糖或蔗糖和酵母水解物。然后，在 10 天的成虫取食后重复进行相同的测试。在低蛋白幼虫饮食中发育会导致新出现的成虫体重降低，但抗脱水和饥饿能力提高，尽管高蛋白幼虫饮食的成虫水分含量最高。无论提供何种饮食，成虫取食都会降低抗脱水或饥饿的能力。无论幼虫饮食史如何，新出现的未喂食的成虫的脱水耐受性明显高于喂食的成虫。脂质储备在饥饿抗性中发挥作用。没有证据表明储存的营养物质产生的代谢水可以延长脱水抗性。我们的研究结果表明，在短期内，营养贫乏的幼虫环境可能导致成虫性能的相关性提高。
