480 ARTHROPODA. 



Order III. Orthoptera. 



Like the Archiptera these are hemimetabolous or in a few 

 cases ametabolous, and the mouth parts (fig. 486) are fitted for 

 biting, the mentum being cleft. On the other hand the wings 

 have lost the delicate membranous character and have become 

 more parchment-like, the fore wings being smaller and serving as 

 covers for the larger, softer, and folded hind wings, which are the 

 efficient organs of flight; the condition in these respects recalling 

 somewhat the Coleoptera. The abdomen bears cerci and fre- 

 quently stylets. In internal anatomy the large number of Malpi- 

 ghian tubules is noticeable (fig. 491). 



Sub Order I. CURSORIA. With rather long legs fitted for rapid run- 

 ning. Only the cockroaches (BLATTID.E) belong here. Wings may be 

 absent, according to the species, in either sex, but more frequently in 

 females. The more common cockroach, the ' Croton bug ' (Blatta ger- 

 manica *), is a well-known pest in houses. The larger Periplaneta orien- 

 talis* is common in ships and bakeries. Other species in our woods. 



Sub Order II. DEEMATOPTERA (Euplexoptera). Front wings short 

 elytra ; the hinder wings being folded crosswise and packed beneath them, 

 or rudimentary ; cerci developed to a forceps-like structure terminating 

 the body, whence the name Forficula* given one genus. Labidura* 

 These forms are often called earwigs, from an erroneous belief that they 

 enter the human ear and injure the drum. The group on account of its 

 wing structure is often made a distinct order. 



Sub Order III. GKESSORIA. Legs long, slender, adapted to a slow 

 walking motion. In the MANTID.E the prothorax is very long and bears a 

 pair of long raptorial feet which when at rest are held in a position which 

 causes these insects to be known as 'praying Mantes.' Phasmomantis* 

 warm countries. PHASMID^E, with short prothorax, almost exclusively 

 tropical, represented throughout northeastern United States by Diaphero- 

 mera femorata* the walking stick. The members of this family are 

 noted for their mimicry of twigs and leaves (fig. 12.) 



Sub Order IV. SALTATORIA. Hinder legs long, strong, and for 

 jumping ; the other pairs much smaller. Hinder femora large and muscu- 

 lar, tibiae elongate and spined. Wings usually functional and in the 

 migrating species capable of sustained flight. Produce sound (stridulate) 

 by rubbing the anterior wings together (Locustidae, Gryllidae) or against 

 the legs (Acridiidae). Tympanal apparatus (p. 468) on the anterior tibiae 

 (Locustidae, fig. 493, and many Gryllidae) or on the first somite of the 

 abdomen (fig. 492). Stridulation occurs only in males, and in our com- 

 mon crickets the number of notes is directly dependent upon tempera- 

 ture, which, on the Fahrenheit scale, may be determined by the formula, 



T = 50 + ?LZ! , in which T stands for temperature and n for number 



