308 ELEMENTARY ENTOMOLOGY 



THE EUPLEXOPTERA 



This order includes a single family the members of which have four wings : 

 the first pair are leathery or horny, meeting in a straight line down the middle 

 of the back ; the second pair are membranous, with numerous radiating veins 

 folded lengthwise like a fan and then crosswise under the first pair. Earwigs. 

 (Page 87) FORFICULIDAE 



KEY TO THE FAMILIES OF ORTHOPTERA 



A. Third pair of legs not adapted for leaping. 



B. Body oval, dorsoventrally compressed. Cockroaches. (Page 77) 



BLATTIDAE 

 BB. Body elongate, not dorsoventrally compressed. 



C. First pair of legs fitted for grasping and holding their prey ; prono- 

 tum longer than any of the other body segments. Praying mantis. 



(Page 78) MANTIDAE 



CC. First pair of legs not fitted for grasping and holding prey ; prono- 



tum short. Walking-sticks. (Page 80) PHASMIDAE 



A A. Third pair of legs adapted for leaping. 



B. Antennae shorter than body. Locusts. (Page 8 1). . . ACRIDIDAE 

 BB. Antennae longer than body. 



C. Tarsi consisting of four segments. Long-horned grasshoppers. 



(Page 83) LOCUSTIDAE 



CC. Tarsi consisting of three segments. Crickets. (Page 85) 



GRYLLIDAE 



THE THYSANOPTERA 



This order includes but a single family of very small insects with long, 

 narrow, membranous wings, having but few or no veins and bordered by a 

 fringe of long hair ; the tarsi swollen, bladderlike, with or without claws. 



PHYSOPODAE 



KEY TO THE FAMILIES OF HEMIPTERA 1 



A. Wingless insects with fleshy unjointed beak; parasitic on mammals. 

 (Suborder PARASITICA.) Suctorial lice. (Page 121) . . PEDICULIDAE 

 A A. Winged or wingless insects, with a jointed beak. 



B. First pair of wings leathery at the base, membranous at the tip, the 

 tips overlapping on the back ; beak arising from front part of head. 



Suborder HETEROPTERA 

 C. Antennae shorter than head. Aquatic or shore insects. 



D. With two ocelli. Toad-bugs GALGULIDAE 



DD. Without ocelli. 



1 Adapted from Kellogg's " American Insects." 



