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Proc. Arthropod. Embryol. Soc. Jpn. 48, 51–52 (2017)Ⓒ 2017 Arthropodan Embryological Society of Japan
ISSN 1341–1527

Development of Gnathal Appendages of a Wood-feeding Cockroach,
Cryptocercus punctulatus Scudder (Insecta: Blattodea,Cryptocercidae)*1,*2
Apisit THIPAKSORN1, 2, 3), Ryuichiro MACHIDA1, 2), Christine NALEPA4),
Donald MULLINS5) and Kiyoto MAEKAWA6)
Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305–8572, Japan
Sugadaira Research Station, Mountain Science Center, University of Tsukuba, Sugadaira Kogen, Ueda, Nagano 386–2204, Japan3)
Department of Zoology, Kasetsart University, Chatuchak, Bangkok, 10900, Thailand
4)
Department of Entomology, North Carolina State University, Raleigh, NC 27695–7613, USA
5)
Department of Entomology, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061–0319, USA
6)
Department of Biology, Faculty of Science, University of Toyama, 3190 Gofuku, Toyama 930–8555, Japan
E-mail: a_thipaksorn@yahoo.com (AT)1)2)

Development of gnathal appendages in Cryptocercus
punctulatus was followed with scanning electron microscopy.
The oothecae of C. punctulatus were collected from rotten
logs at the Mountain Lake Biological Station, Virginia, USA.
The eggs in the ootheca, of which crest structure was cut
along the median line prior to fixation, were fixed with a 50%
dilution Karnovskyʼs fixative for two days, and stored in a 70%
ethanol. The fixed embryos were removed from the egg,
dehydrated, critical-point dried, and coated with gold using
standard procedures. They were then observed under aTOPCON SM-300 scanning electron microscope.
Whereas the maxillary and labial appendages are divided
into the proximal coxopodite and distal telopodite, themandibular appendage does not suffer from any divisions,being represented only by coxopodite without telopodal
elements developed. The maxillary and labial telopodites
develop into the palps. The coxopodite is subdivided into thecardo and stipes in the maxilla, and into the postmentum andprementum in the labium.
Two swellings arise in the coxopodites of maxilla andFig. 1 SEMs of gnathal appendages of Cryptocercus punctulatus embryos in the middle (A) and late (B) developmental stages. See the text.
An: antenna, Ga: galea, Gl: glossa, In: incisor, La: lacinia, LbP: labial palp, Md: mandible, Mo: molar, MxP: maxillary palp, Pgl:paraglossa. Scales = 50 µm.
*1 Abstract of paper read at the 49th Annual Meeting of the Arthropodan Embryological Society of Japan, June 7–8, 2013 (Tsukuba-san, Ibaraki).
*2 This article, which was accepted in 2013 and should have been published in 2014, was printed in 2017 being much delayed due to various circumstances.

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labium as coxopodal endites: the medial lacinia and lateral
galea in the maxilla, and medial glossa and lateral paraglossa
in the labium (Fig. 1A). In the mandible, two teeth, i.e., thedistal incisor and proximal molar teeth are formed, each ofwhich may be homologized with the maxillary galea and labial

paraglossa and with the maxillary lacinia and labial glossa,
respectively (Fig. 1B).
With the progressive cephalization, the labial
coxopodites of both sides come near to and finally fuse witheach other, to form the prementum and postmentum.