The reproductive biology of Ptomascopus morio , a brood parasite of Nicrophorus
The reproductive biology of Ptomascopus morio , a brood parasite of Nicrophorus
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毛蛉(Ptomascopus morio)的繁殖生物学
DOI：
10.1017/s0952836901001637
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发表时间：
2006
影响因子：
2
通讯作者：
D. Sikes
中科院分区：
文献类型：
--
作者：
S. Trumbo;M. Kon;D. Sikes
粉虱（粉虱属和粉虱属）使用小尸体作为幼体的食物来源，这是一种与其他粉虱不同的繁殖生态。众所周知，微翅虫（Nicrophorus）具有利用小尸体的适应性（释放性信息素，掩埋、磨圆和去除尸体上的毛发，调节窝窝大小，反刍给幼鸟，防止被捕食），但关于其姐妹类群Ptomascopus的信息却很少。像尼科弗蝇一样，雄性tomascopus morio释放信息素来吸引雌性。在没有腐肉竞争对手的情况下，发现斑胸鱼的父母与尸体和他们的后代呆在一起长达10天。我们测试了六种假设，以检验幼崽是否从长时间的亲子接触中受益。(1)没有证据表明父母埋葬或以其他方式先发制人的尸体来减少竞争压力。(2)我们没有发现父母影响尸体分解的证据。这一点得到了实验操作的支持，在父母在场的尸体上的产卵量（幼虫数量和总孵化质量）并不比在没有父母“准备”的尸体上的产卵量大。胴体不圆，成虫除毛少。(3)亲本的存在减少了与腐蝇幼虫竞争的负面影响，有利于幼虫的繁殖。这很可能是成年甲虫捕食的结果。(4)雌性根据胴体的大小调整卵窝的大小。然而，在幼体发育到幼虫阶段后，父母并没有进行第二次调整（子女同类相食），这发生在幼鱼身上。(5)虽然观察到父母在胴体上开食孔，但这对幼虫的正常生长和存活不是必需的。没有观察到父母直接通过反流喂养孩子。(6)最后，当有同种入侵者存在时，父母并不减少对其后代的捕食。这些发现表明，在雌性父母根据资源的大小调整了产卵数量后，唯一的父母利益是清除蝇幼虫的尸体。与微粉虾的其他区别还包括产卵期较长（5天），发现尸体后卵巢体积和幼体激素滴度的变化不太明显。在日本京都进行的一项田间试验中，8月期间，共21窝黑腹白腹蝶中有17窝含有莫里弓形虫幼虫。在一年中的其他时间，当四爪螨占据了尸体时，小蠹蛾-斑尾蝇混合的卵群不太常见。在实验室中，莫里尼奥疟原虫能够寄生20个白蚁群中的19个。从其产卵方式、亲代行为的缺失以及野外与大纹夜蛾的相互作用来看，大纹夜蛾是小纹夜蛾的一种幼虫寄生。
Nicrophorine beetles (Nicrophorus and Ptomascopus spp.) use small carcasses as a food source for young, a breeding ecology distinct from other silphid beetles. While adaptations to the use of small carcasses are well known for Nicrophorus (emitting sex pheromone, burying, rounding and removing hair from carcasses, regulating brood size, regurgitating to young, and preventing predation), there is little information regarding its sister group, Ptomascopus. Like Nicrophorus, Ptomascopus morio males emit pheromone to attract females. In the absence of carrion competitors Ptomascopus morio parents were found to stay with a carcass and their brood for up to 10 days. We tested six hypotheses to examine whether young benefit from this long period of parent‐offspring contact. (1) There was no evidence that parents buried or otherwise pre-empted carcasses to reduce competitive pressure. (2) We found no evidence that parents influenced the decomposition of the carcass. This was supported by experimental manipulations in which brood production (number of larvae and total brood mass) was no greater on carcasses on which parents were present than on carcasses not ‘prepared’ by parents. In addition, the carcass was not rounded and little hair was removed by the adults. (3) The presence of parents benefited the brood by reducing the negative effects of competition with carrion fly larvae. This likely resulted from predatory feeding by adult beetles. (4) Females adjusted clutch size to the size of the carcass. Parents, however, did not make a second adjustment in brood size after young reached the larval stage (filial cannibalism), as occurs in Nicrophorus. (5) Although parents were observed to open feeding holes in the carcass, this was not necessary for normal larval growth and survival. Parents were not observed to feed young directly by regurgitation. (6) Lastly, parents did not reduce predation on their brood when a conspecific intruder was present. These findings suggest that after the female parent adjusts clutch size to the size of the resource, the only parental benefit is clearing the carcass of fly larvae. Other differences with Nicrophorus include an extended period of oviposition (5 days) and less pronounced changes in ovarian mass and juvenile hormone titers in response to discovery of a carcass. In a field experiment in Kyoto, Japan, 17 of 21 broods of N. concolor during August contained larvae of P. morio. Mixed Nicrophorus‐Ptomascopus broods were less common at other times of the year and when N. quadripunctatus occupied carcasses. In the laboratory, P. morio was able to parasitize 19 of 20 broods of N. concolor. The pattern of oviposition, the absence of explicit parental behaviours, and the interactions with N. concolor in the field suggest that Ptomascopus morio is a brood parasite of Nicrophorus.