ECTOPARASITES AND MATING SUCCESS OF MALE ENALLAGMA EBRIUM DAMSELFLIES (ODONATA, COENAGRIONIDAE)
ECTOPARASITES AND MATING SUCCESS OF MALE ENALLAGMA EBRIUM DAMSELFLIES (ODONATA, COENAGRIONIDAE)
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DOI：
10.2307/3545076
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发表时间：
1991-04-01
期刊：
影响因子：
3.4
通讯作者：
FORBES, MRL
中科院分区：
文献类型：
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作者：
FORBES, MRL
一些研究人员发现雄性交配成功与寄生程度之间存在负相关关系。这种交配偏差是否是由于雌性选择抗寄生虫的雄性作为交配，还是由于寄生虫介导的雄性获得雌性的竞争力下降，引起了相当多的讨论。我发现，单雄性豆娘 Enallagma ebrium (Hagen) (Odonata: Coenagrionidae) 明显且持续地被更多的幼虫水螨 (Arrenurus spp. 和 Limnochares americana) 寄生。 Lundblad）比雄性与雌性串联或交配捕获的情况要多。相比之下，雄性体型与短期交配成功率的相关性不一致，尽管雄性体型和螨虫数量之间存在一致的负相关性，并且在 7 个采样日中有 2 天具有统计显着性。这种自然共变的存在及其对雄性交配成功的可能影响尚未得到广泛讨论。最后，我发现，与轻度寄生的雄性相比，重度寄生的雄性对雄性模型的存在反应较少，并且进行更多的觅食旅行。对于外寄生的雄性E. ebrium来说，短期交配偏差似乎是由于重度寄生的雄性在接近雌性方面的竞争力下降造成的。此外，我的研究结果强烈表明，竞争力的明显下降反映了严重寄生的雄性决定追求能量廉价的交配策略。
Several researchers have found inverse relationships between mating success of males and degree of parasitism. Whether such mating biases result from female choice of parasite-resistant males as mates, or from parasite-mediated reductions in male competitiveness for access to females, has stimulated considerable discussion.I found that single male damselflies, Enallagma ebrium (Hagen) (Odonata: Coenagrionidae), were significantly and consistently parasitized by more larval water mites (Arrenurus spp. and Limnochares americana Lundblad) than were males caught either in tandem or copula with females. In contrast, male size was inconsistently related to short-term mating success, although there was a consistent negative correlation between male size and mite numbers which was statistically significant on 2 of 7 sampling days. The existence of such natural covariation and its possible effect on male mating success has not been widely discussed. Lastly, I found that heavily-parasitized males responded less often to the presence of male models, and took significantly more foraging trips, than did lightly-parasitized males.Short-term mating biases with respect to ectoparasitism for E. ebrium males appears to result from reductions in competitiveness of heavily-parasitized males for access to females. Furthermore, my results strongly suggest that apparent reductions in competitiveness reflect decisions by heavily-parasitized males to pursue mating tactics which are energetically inexpensive.