环境胁迫对丽斗蟋翅型分化的影响机制及两型雌虫生理权衡的内分泌控制机理

The evolution of wing is unique to insect in the phylum Arthropoda, and it is probably of the most important factors reponsible for their success of flight ability, they must have enjoyed a greated advantage over other organisms as a result of increased in the capacity of foraging, searching for a mate and new habitats, and escaping from predators. In spite of such advntages, some species have lost their flight ability by reducing the size of wings or losing the wings comletely during the course of evlotion. Some species have become dimorphic for flight without showing any apparent modification in the wings, and some others have developed a behavior to shed their wings after adult emergence..In this study, the effect of environment stress such as appendage injury, 0 or 30 ℃ pulse and deteriorate food on wing variatin of Velarifictorus ornatus is investigated first. From the above results, the sensitive period and regular pattern of stress on wing variation can be understood. Then juvenile hormone (or transplantation of corpus allatum) are used to presumptive long-winged individuals and precocene are applied to presumptive short-winged individuals to investigate the endocrine control mechanism of environment stress causing wing variation..After adult emergence, the juvenile hormone and ecdysteroid titres will be measured first. Then, we use a prospective design, applying juvenile hormone to long-winged individuals to increase the juvenile hormone titres, and, in the opposite direction, we apply precocene to short-winged individuals to destroy the corpora allata thus preventing synthesis of juvenile hormone. The subsequent development of flight muscle and reproductive organs will be compared to clarify the endocrine control mechanism of the physiological trade-off between the development of flight muscle and reproductive organs in the wing-dimorphic cricket V. ornatus. Meanwhile, in order to elucidate the relations between the large-amplitude, diurnal cycle in juvenile hormone titer and wing dimorphism, the effect of flying on the juvenile hormone titres or the effect of juvenile titres on flying will also be investigated. These results are important for us to understand the endocrine conrol mechanism of wing variation and physiological trade-off between the development of flight muscle and reproduction more closely and are much significant for us to design good ways to control the pests that show dispersal polymorphism.

昆虫飞行能力的获得使昆虫寻偶、觅食、避敌及扩大分布的效率都得到飞跃性的提升。然而，在一些昆虫种类中，部分个体退化为不具飞行能力的短翅型和无翅型。这些昆虫的翅"为什么"、"如何"向退化的方向进化？此类科学问题一直备受国内外学者的关注。本项目拟以丽斗蟋为材料，研究环境胁迫对昆虫翅型分化的影响，弄清环境胁迫对昆虫翅型分化的影响规律；调查受环境胁迫个体血淋巴内保幼激素滴度的变化，结合外用保幼激素与早熟素，揭示环境胁迫对昆虫翅型分化影响的内分泌控制机理；通过早熟素、保幼激素处理（咽侧体移值）、血淋巴内保幼激素与蜕皮激素滴度测定，辅以脱翅和吊飞实验，阐明丽斗蟋翅二型雌虫飞行与繁殖发育生理权衡的内分泌控制机理。本研究将为昆虫的翅型分化、迁移扩散及种内翅多型维持机制和进化意义提供理论依据和基础，同时对具有迁移扩散多型性的农林害虫治理亦有一定的理论指导意义。

昆虫飞行能力的获得使昆虫寻偶、觅食、避敌及扩大分布的效率都得到了飞跃性的提升。然而，一些昆虫种类中，部分个体退化为不具飞行能力的短翅型或无翅型个体，这些昆虫的翅“为什么”、“如何”向退化的方向进化？此类科学问题一直备受国内外学者的关注。本项目以具翅多型现象的丽斗蟋为研究材料，首先探讨了环境因素与密度及胁迫作用对翅型分化的影响，证实了光周期和温度对翅型分化无明显影响，密度和附肢损伤对翅型分化影响明显，同时揭示高密度诱导的成虫短翅化与密度增加后成虫相互打斗引起的附肢损伤有关。其次分别对丽斗蟋长翅型个体外用保幼激素，短翅型个体外用早熟素从正反两个方面研究了翅二型昆虫飞行与繁殖发育的内分泌控制机理，阐明了翅二型雌虫飞行与繁殖发育受保幼激素调控，而翅二型雄虫飞行肌与繁殖器官发育不受外用保幼激素与早熟素的影响，表明丽斗蟋翅二型雌、雄成虫飞行肌与繁殖器官的内分泌控制机理可能存在差异。同时采用定量投食的方法研究了食物胁迫对丽斗蟋翅二型成虫飞行肌与繁殖发育的影响，确认在遭受营养缺失时，翅二型雄虫在飞行与繁殖间同样存在权衡关系。另外，采取重量营养指数测定了成虫羽化12 d内长、短翅型个体食物消化能力及消化酶活性差异及变化规律，揭示了短翅型雌虫羽化后早期卵巢快速发育是较大取食量与较高食物转化率联合作用结果；而长、短翅型雄虫食物取食量、食物转化率、食物利用率与增长量均无显著差异。羽化后不同时期两型个体中肠内消化酶活性存在差异，该差异可能与羽化后不同时期，两型成虫在飞行与繁殖投资中对不同能源物质的需求有关。最后，我们比较了翅二型雄虫性成熟时间、交配频度及对雌虫的授精能力差异，在成虫羽化后早期，短翅型雄虫性成熟时间更早，产生的精包也显著重于长翅型雄虫，同时在24 h交配期内，短翅型雄虫交配频度及产生的精包重量都显著高于长翅型雄虫，相邻两次的交配间隔也显著低于长翅型雄虫，短翅型产生的精包对雌虫授精能力也显著高于长翅型雄虫，研究结果证明丽斗蟋翅二型雄虫虽然飞行与繁殖发育无生理权衡关系，但在飞行与繁殖能力间同样存在权衡关系。研究结果对昆虫翅型分化的形成机制及翅型分化的进化意义提供了新的理论依据和基础，同时对具有迁移扩散多型性的农林害虫治理亦有一定的理论指导意义。