17Proc. Arthropod. Embryol. Soc. Jpn. 49, 17 (2016)Ⓒ 2016 Arthropodan Embryological Society of Japan
ISSN 1341–1527

Postembryonic Development of Zorotypus caudelli Karny (Insecta,Zoraptera, Zorotypidae)*
Yuta MASHIMO and Ryuichiro MACHIDA
Sugadaira Montane Research Center, University of Tsukuba, Sugadaira Kogen 1278–294, Ueda, Nagano 386–2204, Japan
E-mail: mashimo@sugadaira.tsukuba.ac.jp (YM)

Zoraptera (ground lice, angel insects) are small, cryptic
neopteran group living subcortically in decaying logs
throughout the tropical and subtropical zones. Forty extant
and nine fossil species are described, but their diversity
remains underexplored (Yin et al., 2015). The systematic
position of Zoraptera is one of the most controversial problems
in insect phylogeny since the group was discovered 100 years
ago (Mashimo et al., 2014c).
Even though investigation of Zoraptera has markedly
intensified in the last decade (cf. Mashimo et al., 2014c), thebiology is still very insufficiently known. Several studies on
the life history (e.g. Riegel & Eytalis, 1974; Shetlar, 1974) areavailable. However, the descriptions are fragmentary and the
documentation of details insufficient. Embryonic development
was recently described (Mashimo et al., 2014a). However, as
the number of nymphal instars has only been suggested to befour or five (Riegel & Eytalis, 1974; Shetlar, 1974), thepostembryonic stages remain insufficiently known. Here we
described the postembryonic development in detail using
Zorotypus caudelli Karny, 1927 (Zoraptera, Zorotypidae)(Mashimo et al., 2014b).
Based on captive breeding, the postembryonicdevelopment of Z. caudelli was investigated. The number ofnymphal instars in Z. caudelli is five. Apterous and winged
forms differentiate in the 4th nymphal instar. In the 4th instarof the winged form, small wing pads and small ocular spots
appear. In the 5th instar, the wing pads elongate and the ocularspots are widened, and three ocelli are differentiated. The twosexes closely resemble each other as in other zorapteranspecies, and sexual dimorphism does not appear until the final(5th) nymphal instar: in the 5th instar of males, setae increasein number on the 9th and 10 + 11th abdominal terga, and asmall posteromedial swelling related to mating hook appearson the 10 + 11th abdominal tergum.
References
Mashimo, Y., R.G. Beutel, R. Dallai, C.-Y. Lee and R. Machida (2014a)
Embryonic development of Zoraptera with special reference toexternal morphology, and its phylogenetic implications (Insecta).
Journal of Morphology, 275, 295–312.
Mashimo, Y., R.G. Beutel, R. Dallai, C.-Y. Lee and R. Machida (2014b)
Postembryonic development of the ground louse Zorotypus
caudelli Karny (Insecta: Zoraptera: Zorotypidae). Arthropod
Systematics & Phylogeny, 72, 55–71.
Mashimo, Y., Y. Matsumura, R. Machida, R. Dallai, M. Gottardo, K.
Yoshizawa, F. Friedrich, B. Wipfler and R.G. Beutel (2014c) 100years Zoraptera - a phantom in insect evolution and the history of
its investigation. Insect Systematics & Evolution, 45, 371–393.
Riegel, G.T. and S.J. Eytalis (1974) Life history studies on Zoraptera.
Proceedings North Central Branch, Entomological Society ofAmerica, 29, 106–107.
Shetlar, D.J. (1974) The biology, morphology, and taxonomy of Zorotypus
hubbardi Caudell (Insecta: Zoraptera). Masterʼs thesis, The
University of Oklahoma, Norman.
Yin, Z.-W., L.-Z. Li and C. Wu (2015) New and little known speciesof Zorotypus Silvestri (Zoraptera: Zorotypidae) from China.
Zootaxa, 4007, 557-566.

* Abstract of paper read at the 50th Annual Meeting of the Arthropodan Embryological Society of Japan, July 3–4, 2014 (Fuchu, Tokyo)