4 THE COCCIDAE 



antennae and in the general appearance of the families of this 

 suborder, as generally recognized, has led to its subdivision into 

 two groups or suborders. The structure of the wings, the form 

 and origin of the mouth-parts, and the presence of many other 

 minor differences emphasize the Desirability of this subdivision : 



SUBORDERS OF HEMIPTERA 



a. Head with rostrum attached to its cephalic end, distant from the 

 prothoracic legs, ventro-meson of the head distinctly longer than 

 the distance on the venter between compound eyes; mesothoracic 

 wings, when present, with proximal portion thickened and distal 



portion membranous. HETEROPTERA* 



aa. Head with rostrum attached to its ventral aspect near the articula- 

 tion of prothoracic legs, ventro-meson distinctly shorter than distance 

 on the venter between compound eyes; mesothoracic wings, when 

 present, always of same texture throughout, never thickened on 

 proximal and membranous on distal portion. 

 b. Antennae minute and inconspicuous, setiform or awl-shaped; tarsi 



with three segments; prothorax large and conspicuous 



HOMOPTERA. 



bb. Antennae long and filiform, rudimentary, or wanting, never seti- 

 form or awl-shaped; tarsi with one or two segments; prothorax 

 small and frequently inconspicuous. GULAROSTRIA. 



The suborder Heteroptera as here defined includes the super- 

 families and families usually assigned to it. The suborder 

 Homoptera includes the superfamilies Cicadoidea, Jassoidea, Ful- 

 goroidea, and Membracoidea, while to the suborder Gularostria is 

 assigned the Psyllidae, Aphididae, Aleyrodidae, and Coccidae. 

 These groups can be separated by means of the following table : 



FAMILIES OF GULAROSTRIA 



a. Tarsi of adult rarely with less than two segments and usually with 

 two claws, legs never wanting; wings, when present, four in number; 

 eyes in adult always compound, if present in nymph, compound; 

 rostrum always present in nymphs and adults, usually greatly elon- 

 gated and projecting beyond the mesocoxae; adult insects never 

 scale-like, grub-like, or gall-like in form and never immovably fixed 

 to the food plant; nymphs sometimes scale-like, legless, and immov- 

 able, if so, abdomen always provided with a vasiform orifice, 

 b. Wings, when present, membranous; the metathoracic wings al- 

 ways much smaller than the mesothoracic; body of adult and its 

 wings sometimes bearing filaments, threads, or tufts of wax, 

 never densely covered with a fine, white, and powdery wax; 

 nymphs and adults frequently associated, subsimilar in form, both 

 provided with antennae and legs, both capable of locomotion, 

 nymphs never provided with a vasiform orifice. 



