56 



LOWER PTERYGOTA 



evening and early morning;-. They are seldom active during 

 the bright part of the day. The egg-capsules are bean-shaped 

 and contain 50 to 60 or more eggs packed closely together, 

 and after being carried some time are probably slowly 

 extruded, finally left in some crevice. The young hatch 

 from the egg-capsules and for a time are somewhat gregarious 

 and are inclined to cluster together in company with the 

 adult. This ma}' be simply an incident of location, though 



Fig. 22. — The oriental roach (Periplaneta orienfalis): a, female; h, 

 male; c, side view of female; d, half-grown specimen — all natural size. 

 (From Marlatt, Div. Ent., U. S. Dept. Ag.) 



it appears like maternal care. The young are similar to the 

 adults in shape, much flattened, and much lighter in color, 

 and the wing pads are scarcely visible. They grow by 

 successive moults, and with each moult the wing pads 

 increase in size, until in the final moult they acquire the full- 

 sized wings of adults. The development of the nymphs 

 goes on somewhat irregularly during the summer months. 

 An introduced species, the Oriental cockroach {Periplanda 



