Structural features of eggs of the basal phasmatodean Timema monikensis Vickery & Sandoval, 1998 (Insecta: Phasmatodea: Timematidae)

Abstract

Structural features of the eggs of a basal phasmatodean, Timema monikensis Vickery & Sandoval, 1998 (Timematidae) were examined. The eggs of this species are soft and deposited coated with soil and/or other extraneous particles. The chorion, which is transparent and weakly sclerotized, is composed of an endochorion and an exochorion. The non-inclined operculum is located at the anterior pole of the egg. The chorion in the marginal region of the operculum is thinned to form an opercular collar together with the chorion of the egg body. An inverted triangular micropylar plate is on the ventral side of the egg attached to the opercular collar. The micropylar plate is without external differentiations but is specialized inside the chorion. A single micropyle, with a simple funnel-shaped chorionic opening, occurs on either side of the micropylar plate. The posterior mound, located at the posterior pole, is a thickened chorion rich in fine vertical striations, and the serosal cuticle beneath is thickened and highly specialized. The eggs of Timematidae were characterized and compared with those of Euphasmatodea and Embioptera. A phylogenetic discussion is presented, strongly supporting the assemblage of Timematodea, Euphasmatodea and Embioptera as monophyletic.

Development and ultrastructure of the thickened serosa and serosal cuticle formed beneath the embryo in the stonefly Scopura montana Maruyama, 1987 (Insecta, Plecoptera, Scopuridae)

“…In some polyneopteran insects, a specialized serosa and/or serosal cuticle, similar to the plecopteran thickened serosa and serosal cuticle have been reported for Orthoptera (Slifer, 1938;Matthée, 1951;Slifer and Sekhon, 1963), Grylloblattodea (Uchifune and Machida, 2005), Embioptera (Jintsu and Machida, 2009), and Phasmatodea (Jintsu et al, 2010). Slifer (1938) and Slifer and Sekhon (1963) previously conducted experimental embryological studies, combined with TEM, using the grasshopper Melanoplus differentialis.…”

External macro- and micromorphology of the male of the stick insect Hermarchus leytensis (Insecta: Phasmatodea) with phylogenetic considerations

“…Over this evolutionary time Timema and Euphasmatodea have acquired significant morphological differences [1]. Timema, with 21 Neartic species [9], has been morphologically characterized in various character systems [10][11][12][13][14][15]. In comparison the morphology of the diverse Euphasmatodea is less well documented, as accurate studies of key systematic characters are available for only a few taxa among the $3000 species known worldwide.…”