Nalepa Christine A, Maekawa Kiyoto, Shimada Keisuke, Saito Yukari, Arellano Consuelo, Matsumoto Tadao
Department of Entomology, North Carolina State University, Raleigh, NC 27695-7613, USA.
Zoolog Sci. 2008 Dec;25(12):1190-8. doi: 10.2108/zsj.25.1190.
Species in the wood-feeding genus Salganea within the cockroach subfamily Panesthiinae (Blaberidae) typically live in biparental families; their first instars suffer high mortality when removed from adults, and in at least one species, adults are known to feed neonates on oral liquids. In the closely related gregarious wood-feeding genus Panesthia , no parental interaction with offspring is known. We compared the external morphology of first instars of these two genera and found that eye development and cuticular pigmentation at hatching are correlated with social structure. First instars of Panesthia have a dark cuticle and well-developed eyes. First instars of Salganea have a pale, transparent cuticle, and eyes significantly smaller than those of Panesthia relative to adult eye size. The body size of the first-instar of Salganea esakii is significantly smaller than that of Panesthia angustipennis spadica , relative to adult body size (24.0 and 27.4% of adult head-capsule width, respectively), but a more general survey suggests that, overall, neonate size may be similar in the two genera. We compared the first instars of these two taxa of Panesthiinae to those in the biparental, wood-feeding cockroach Cryptocercus (Cryptocercidae) and discuss how decreased investment in both integumentary and ocular development in subsocial cockroaches parallels that seen in altricial vertebrates.
蟑螂亚科拟甲蠊亚科（蜚蠊科）中以木材为食的萨尔加内属物种通常生活在双亲家庭中；它们的一龄若虫与成虫分离时死亡率很高，而且已知至少有一种成虫会用口液喂养若虫。在亲缘关系密切的群居性木材取食属拟甲蠊属中，没有发现亲代与后代之间的互动。我们比较了这两个属一龄若虫的外部形态，发现孵化时的眼睛发育和表皮色素沉着与社会结构相关。拟甲蠊属的一龄若虫表皮深色且眼睛发育良好。萨尔加内属的一龄若虫表皮浅色、透明，相对于成虫眼睛大小，其眼睛明显小于拟甲蠊属的一龄若虫。相对于成虫体型，江崎萨尔加内一龄若虫的体型明显小于窄翅拟甲蠊指名亚种（分别为成虫头壳宽度的24.0%和27.4%），但更全面的调查表明，总体而言，这两个属的新生若虫大小可能相似。我们将拟甲蠊亚科这两个类群的一龄若虫与双亲性、以木材为食的蟑螂隐尾蠊（隐尾蠊科）的一龄若虫进行了比较，并讨论了亚社会性蟑螂在体表和眼部发育方面投入的减少与晚成脊椎动物的相似之处。
