The analysis of factors limiting the distributions of drosophilid flies

果蝇分布限制因素分析

基本信息

批准号：
14540571
负责人：
KIMURA Masahito
金额：
$ 2.24万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540571/
关键词：
Drosonhilid flies Latitudinal distribution Cold tolerance Heat tolerance Metabolic rates Walking speed Pupal period Parasitic wasps 分布の南限耐寒性防御反応北限南限

项目摘要

Drosophilid flies occur mainly in woodlands from tropical to arctic regions. However, the distribution rage of single species is not so wide, and the distribution of tropical species is almost restricted in tropical regions and that of temperate species in temperate regions. This study focuses on the question why tropical species are not distributed in temperate regions and temperate species are not present in tropical regions. According to the present study with 30 drosophilid species from Japan, tropical species are not cold tolerant, and this inhibits them to colonize temperate regions. It has been reported in many organisms that cold-adapted species have higher metabolic rates than species from warmer regions. However, such tendency was not observed in drosophilid flies. On the other hand, the absence of cold-tolerant species in warmer regions suggests that the acquisition of cold tolerance resulted in the loss of adaptability to warmer regions. Here, walking speed and the rate of pupal development were compared for 28 drosophilid species. If walking speed is reduced, they would become vulnerable to predators. If the rate of pupal development is retarded (i.e., pupal period is prolonged), they would also become vulnerable to predators, parasitoids and infectious microorganisms. In our experiments, cold-tolerant species had lower walking speed and lower rate of pupal development, suggesting that cold-tolerant species are disadvantageous in warmer regions than cold-intolerant species. However, little is known on predators, parasitoids or infectious microorganisms of drosophilids. In this study, we made a survey on parasitoid wasps of drosophilid flies in Japan and recorded about 20 species. It is needed to examine whether or not cold-tolerant species are more heavily attacked by parasitoids than cold-intolerant species.

果蝇主要出现在从热带到北极地区的林地中。但单一物种的分布范围并不广泛，热带物种的分布几乎局限于热带地区，温带物种的分布几乎局限于温带地区。本研究的重点是为什么热带物种不分布在温带地区，而温带物种不存在于热带地区的问题。根据目前对日本 30 种果蝇物种的研究，热带物种不耐寒，这阻碍了它们在温带地区的定居。据报道，在许多生物体中，适应寒冷的物种比来自温暖地区的物种具有更高的代谢率。然而，在果蝇中没有观察到这种趋势。另一方面，温暖地区缺乏耐寒物种表明，耐寒性的获得导致了对温暖地区的适应性丧失。此处，对 28 种果蝇物种的行走速度和蛹发育速率进行了比较。如果行走速度降低，它们就会变得容易受到掠食者的攻击。如果蛹发育速度迟缓（即蛹期延长），它们也将变得容易受到捕食者、寄生蜂和传染性微生物的侵害。在我们的实验中，耐寒物种的行走速度较低，蛹发育率较低，这表明耐寒物种比不耐寒物种在温暖地区处于不利地位。然而，人们对果蝇的捕食者、拟寄生物或传染性微生物知之甚少。在这项研究中，我们对日本果蝇的寄生蜂进行了调查，记录了大约 20 种。需要检查耐冷物种是否比不耐冷物种更容易受到寄生蜂的攻击。