CLASSIFICATION OF INSECTS 305 



A A. Mouth-parts adapted for sucking. 



B. Mouth-parts not adapted for piercing. 



C. Body covered with scales, wings usually broad. Butterflies and 



moths. (Page 172) LEPIDOPTERA 



CC. Body not covered with scales, wings comparatively narrow. 

 D. Mandibles, if present, not fitted for biting. 



E. Two pairs of wings fringed with hair. Thrips. PHYSOPODA 

 EE. One pair of wings, usually naked or with microscopic hairs. 



Flies. (Page 2 1 8). , DIPTERA 



DD. Mandibles normally developed HYMENOPTERA 



BB. Mouth-parts adapted for piercing. 



C. Mouth-parts consisting of a jointed tube containing the bristlelike 

 mandibles and maxillae. Bugs. (Page 107) . . . HEMIPTERA 

 CC. Mouth-parts consisting of a fleshy tube containing usually bristle- 

 like mandibles and maxillae. 

 D. Wingless insects ; body laterally compressed. Fleas. (Page 240) 



SlPHONAPTERA 



DD. Winged or wingless insects, body not laterally compressed. 

 E. Tarsus provided with single strong, hooklike claw. Wing- 

 less parasitic lice of mammals. (Page 107). HEMIPTERA 

 EE. Tarsus normal. Winged or wingless insects. (Page 218) 



DIPTERA 



KEY TO THE FAMILIES OF APTERA 1 



A. Abdomen elongate, composed of at least ten segments ; antennae many- 

 jointed ; abdomen usually provided with a pair of two-or-m ore-jointed, fila- 

 mentous, or forceplike appendages. (Page 74) Suborder I, THYSANURA 



B. Body covered with scales LEPISMIDAE 



BB. Body not covered with scales. 



C. Abdomen without caudal appendages . . . ANISOPHAERIDAE 

 CC. Abdomen with caudal appendages. 



D. Caudal appendages sickle-shaped . . . . . JAPYGIDAE 

 DD. Caudal appendages consisting of many-jointed filaments. 



CAMPODEIDAE 



A A. Abdomen composed of not more than six segments; antennae of not 

 more than eight segments; ventral spring usually present, but no ter- 

 minal abdominal appendages. Springtails. (Page 74) 



Suborder II, COLLEMBOLA 

 B. Ventral spring present. 



C. Ventral spring attached on penultimate abdominal segment. 

 D. Abdomen globular, only slightly longer than broad. 



SMINTHURIDAE 

 DD. Abdomen cylindrical, longer than broad. ENTOMOBRYIDAE 



1 Revised from Dr. K. W. v. Dalla Torie's " Die Gattungen und Arten der 

 Apterygogenea." 



