Lin Liangguan, Wen Jiazhen, Li Sheng, Liu Fangfang
Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied Technology, Institute of Insect Science and Technology & School of Life Sciences, South China Normal University, Guangzhou 510631, China.
Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510631, China.
Insects. 2022 Jun 16;13(6):551. doi: 10.3390/insects13060551.
The American cockroach, (Insecta: Blattodea: Solumblattodea: Blattidae), is an urban hygiene pest but also a model organism for physiology and neuroscience study. However, the current description of the developmental process of the American cockroach is insufficient. In this study, we provide a life table of the American cockroach in a stable environment, including embryonic development, nymphal instars and adult reproduction. Our results show that there are 14 nymphal instars of the American cockroach in groups with sufficient living materials and space. The secondary sexual characteristics are evident in last-instar nymphs and adults, namely, the complete absence of the anal stylus in females. The entire embryonic development process was divided into 20 stages on the basis of lateral-view observations of the embryos. The formation of the embryo involves the fusion of paired blastoderm regions with higher cellular density, similar to that in other insects of Polyneoptera. With respect to reproduction, the gamogenetic females produced their first ootheca earlier than the parthenogenic females, and the frequency of oviposition was higher for the former throughout adulthood. Interestingly, group living seems to improve the parthenogenesis success rate in the American cockroach.
美洲大蠊（昆虫纲：蜚蠊目：真蜚蠊亚目：蜚蠊科）是一种城市卫生害虫，但也是生理学和神经科学研究的模式生物。然而，目前对美洲大蠊发育过程的描述并不充分。在本研究中，我们提供了美洲大蠊在稳定环境中的生命表，包括胚胎发育、若虫龄期和成虫繁殖。我们的结果表明，在有足够生活材料和空间的群体中，美洲大蠊有14个若虫龄期。次生性征在末龄若虫和成虫中明显，即雌性完全没有肛针。基于对胚胎的侧视图观察，整个胚胎发育过程分为20个阶段。胚胎的形成涉及细胞密度较高的成对胚盘区域的融合，这与其他多新翅类昆虫相似。在繁殖方面，有性生殖的雌性比孤雌生殖的雌性更早产生第一个卵鞘，并且在整个成年期，前者的产卵频率更高。有趣的是，群居似乎提高了美洲大蠊孤雌生殖的成功率。
