扁颅蝠和褐扁颅蝠体表寄生革螨的宿主选择

该文通过野外调查和室内行为实验,研究了扁颅蝠(Tylonycteris pachypus)和褐扁颅蝠(T.robustula)与其体表寄生革螨(雷氏巨刺螨(Macronyssus radovskyi)及拟雷氏巨刺螨(M.pararadovskyi))之间的关系.在野外自然条件下,雌性扁颅蝠的体表寄生革螨负荷量与宿主健康指数呈正相关(Spearman:rs=0.55,P＜0.01,n=24),而在雄性扁颅蝠以及雌、雄褐扁颅蝠中则无相关性(P＞0.05).室内原宿主感染实验发现,扁颅蝠和褐扁颅蝠体表寄生革螨均明显倾向于选择各自的雄性宿主,扁颅蝠雌、雄性感染率分别为(42±12)％和(58±12)％(t=-3.6,df=31,P＜0.01);褐扁颅蝠雌、雄性感染率分别为(37±11)％和(63±11)％(t=-6.1,df=26,P＜0.001).用扁颅蝠体表寄生革螨(拟雷氏巨刺螨)对扁颅蝠与褐扁颅蝠交叉感染后发现,寄生革螨明显选择其原宿主扁颅蝠,扁颅蝠与褐扁颅蝠感染率分别为(71±13)％和(29±13)％(t=9.1,df=29,P＜0.001).以上结果表明,扁颅蝠和褐扁颅蝠的体表寄生革螨负荷量与宿主身体状态无明显相关性,而对宿主性别表现不同偏好;扁颅蝠的体表寄生革螨对宿主表现明显的专一性.

Host selection of ectoparasitic gamasid mites on Tylonycteris pachypus and T. robustula

Correlations of two species of gamasid mites (Macronyssus pararadovskyi and M. radovskyi) and their bat hosts (Tylonycteris pachypus and T. robustula) were studied by field surveys and indoor behavioral experiments. The wild data indicated that mite load was positively correlated with body condition index of female T. pachypus hosts (Spearman: r_s=0.55, P<0.01, n=24). Whereas, mite loads had no correlation with body condition indexes of male T. pachypus and all T. robustula hosts (P>0.05). Indoor original host infection showed that mites preferred male T. pachypus and T. robustula hosts. The infection percentages on male hosts were significantly higher than those on female hosts T. pachypus: male (58±12)%, female (42±12)%, (t=?3.6, df=31, P<0.01); T. robustula: male (63±11)%, female (37±11)%, (t=?6.1, df=26, P<0.001)]. Using M. pararadovskyi (original host T. pachypus) to across infect T. pachypus and T. robustula, we found that mites significantly preferred the original host (t=9.1, df=29, P<0.001). The infection percentages of T. pachypus, and T. robustula were (71±13)% and (29±13)%, respectively. Our results indicated that mite loads of the two bat species were not correlated with body condition indexes of hosts. However, these mites presented different host sexual preferences, and the mites of T. pachypus presented specific host species preferences.