Scott Michelle Pellissier, Panaitof S Carmen
Department of Zoology, University of New Hampshire, Durham, NH 03824, USA.
Horm Behav. 2004 Mar;45(3):159-67. doi: 10.1016/j.yhbeh.2003.09.012.
Extended biparental care is rare in insects but provides an excellent opportunity to investigate the interaction between the endocrine system and the physical and social environment in the regulation of this behavior. Burying beetles (Nicrophorus spp.) have facultative biparental care and depend on locating a small vertebrate carcass that they bury and prepare as food for their young. Commonly, both male and female Nicrophorus orbicollis remain in the burial chamber after eggs hatch to feed and guard the larvae. In both sexes, juvenile hormone (JH) rises rapidly in response to the discovery and assessment of the carcass; it returns to near baseline in 24 h; then in females it reaches very high titers at the onset of maternal care. In this paper, we investigate some social (presence of a mate, mating history, larval age) and environmental (carcass size) factors that may affect this endocrine profile. For females, neither the presence of a mate nor mating status (i.e., virginity) affected the initial rise of JH. However, the absence of a mate significantly depressed the JH rise in males. Eighty-seven percent of the single males buried the carcass like paired males but 87% also released pheromones to attract a mate. JH hemolymph titers in females whose broods were replaced every 24 h with newly hatch larvae were significantly higher than those of females rearing aging broods. Lastly, even though larger carcasses took longer to bury and prepare and oviposition was delayed, neither JH titers nor speed of ovarian development was affected by carcass size.
延长双亲照料行为在昆虫中很少见，但为研究内分泌系统与物理和社会环境在调节这种行为过程中的相互作用提供了绝佳机会。埋葬虫（葬甲属）具有兼性双亲照料行为，它们需要找到小型脊椎动物尸体，将其埋葬并处理后作为幼虫的食物。通常，卵形埋葬虫的雌雄成虫在卵孵化后都会留在埋葬室中，喂养并守护幼虫。雌雄两性的保幼激素（JH）会在发现并评估尸体后迅速升高；24小时内会恢复到接近基线水平；然后在雌性进入母性照料阶段时达到非常高的滴度。在本文中，我们研究了一些可能影响这种内分泌特征的社会因素（配偶的存在、交配历史、幼虫年龄）和环境因素（尸体大小）。对于雌性而言，配偶的存在或交配状态（即是否为处女）均不会影响保幼激素的初始升高。然而，没有配偶会显著抑制雄性保幼激素的升高。87%的单只雄性埋葬尸体的方式与成对雄性相同，但87%的单只雄性也会释放信息素以吸引配偶。每隔24小时用新孵化的幼虫替换一窝幼虫的雌性，其血淋巴中的保幼激素滴度显著高于饲养大龄幼虫的雌性。最后，尽管较大的尸体埋葬和处理所需时间更长且产卵延迟，但保幼激素滴度和卵巢发育速度均不受尸体大小的影响。
