Laboratory of Ecology, Department of Biology, Faculty of Sciences, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka-shi, Fukuoka 812-8581, Japan.
J Insect Physiol. 2010 Jun;56(6):646-9. doi: 10.1016/j.jinsphys.2010.01.011. Epub 2010 Feb 11.
Females generally avoid selecting sites for oviposition which have a high predation risk to increase offspring survival. Previous studies have focused on costs to ovipositing females. However, although offspring may also incur costs by being oviposited at low predation risk sites, no studies have focused on costs to offspring. Such costs to offspring were examined by using Aquarius paludum insularis, females of which avoid eggs parasitism by ovipositing at deep sites. Deep sites are safe from egg parasitism but may be unsuitable for hatching due to environmental factors. We examined the costs to offspring at deep sites by comparing the hatching rate, the duration to hatching and the proportion of drowned larvae between eggs that were set at three levels of water depth (0 cm, 25 cm and 50 cm depth). While the hatching rate at 50 cm was lower than that at 0 cm, the rate at 25 cm did not differ from that at 0 cm. Duration to hatching and the proportion of drowned larvae did not differ between the three depths. It is suggested that the declining survival rate of A. paludum eggs was due to increased water pressure at greater depth. Such a cost may exist in other species and such an observation may aid in understanding oviposition site selection.
雌性通常会避免选择产卵地点，因为这些地点的捕食风险很高，会降低后代的存活率。先前的研究主要集中在对产卵雌性的成本上。然而，尽管在低捕食风险地点产卵的后代也可能会产生成本，但目前还没有研究关注后代的成本。通过使用 Aquarius paludum insularis 来研究后代的成本，这种雌性会选择在深水区产卵，以避免卵被寄生。深水区可以避免卵被寄生，但由于环境因素，可能不适合孵化。我们通过比较三种水深（0cm、25cm 和 50cm）下设置的卵的孵化率、孵化所需时间和溺死幼虫的比例，来研究深水区对后代的成本。虽然 50cm 水深的孵化率低于 0cm，但 25cm 水深的孵化率与 0cm 水深的孵化率没有差异。孵化所需时间和溺死幼虫的比例在三种水深之间没有差异。这表明，A. paludum 卵的存活率下降是由于在更深的地方水压力增加所致。这种成本可能存在于其他物种中，这种观察结果可能有助于理解产卵地点选择。
