CHAPTER XV 

 ORTHOPTEROIDEA (PANORTHOPTERA) 



MANTARIA 

 The Praying Mantis (Paratenodera sinensis) 



Hagan (1917), from whose paper the following account is taken, states 

 that from oothecae deposited in September the insects hatch the following 

 spring. The egg is elongate-oval, somewhat convex ventrally, tapering 

 to a smaller, more pointed anterior micropylar end. It averages 4.5 mm. 

 in length. The germ disk is short, its cephalic end about two-thirds the 

 distance from the anterior pole. After gastrulation it elongates rapidly, 

 developing well-marked cephalic lobes anteriorly. Throughout the entire 

 embryonic life the head end is directed toward the anterior end of the egg. 

 The amnion and serosa develop in the usual way. Very early in the 

 development of the embryo a compact mass of cells is at first found 

 opposite or slightly posterior to the cephalic third of the ventral plate but 

 later shifts slightly more posteriorly. This mass of cells is interpreted 

 as the indusium which in this species does not develop further. 



As the posterior growth of the embryo progresses, the definitive 

 abdominal appendages become clearly recognizable in anteroposterior 

 sequence — the first pair, finger-like pleuropodia; the others, merely 

 prominent swellings. The stomodaeum is discernible shortly before the 

 flexing of the telson ; the proctodaeum is visible immediately after. The 

 median groove is then a deep furrow, and meanwhile the brain and optic 

 plates differentiate. Up to this time the embryo has been lying on the 

 ventral side of the egg with its longitudinal axis in a straight line. The 

 longitudinal axis now suddenly becomes curved, with head and tail still 

 remaining in position ; the middle of the embryo bends toward the lateral 

 margin. The head then moves to the side. The entire embryo next 

 passes laterally around the yolk, maintaining its superficial position, and 

 finally comes to rest until hatching on the dorsal side of the egg, the 

 ventral side of the embryo up. The embryo with a slight twisting 

 motion has thus rotated about its longitudinal axis. 



During the rotation, growth continues. By the time the embryo is in 

 a mid-lateral position, head and thoracic appendages elongate and begin 

 to show segmentation. Tracheal invaginations appear, and the 10 

 definitive abdominal segments with a telson have become evident. By 

 the time the embryo reaches its final dorsal position, the procephalon is 



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