CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 1 23 



I. CocciD^ (Scale Insects) 



Chief Sub-families and Genera 



Chief Sub-fatnilies: 



A. Abdominal spiracles present on each segment; males with compound eyes; 

 adult females with white waxy lamellae. — Orlhezince. 

 AA. Abdominal spiracles absent; males with simple eyes. 



B. Concealed beneath a "scale," formed partly of larval exuviae, partly 

 of secretion; abdomen ending in a "pygidium. " — DiaspincE (Fig. 79). 

 BB. Naked or covered with a waxy secretion, but not beneath a "scale;" 

 abdominal pygidium absent. 



[ C. Extremity of abdomen cleft; anal orifice closed above by a 

 pair of triangular plates, anal ring fringed with setae; waxy 

 scale not separable from the insect. — Coccina. 

 CC. Extremity of abdomen not cleft; no anal triangular plates, anal 

 ring without setae. — Dactylopina (Fig. 81). 

 Chief Genera of the Diaspina: 



A. Scale of female circular to oval with central, sub-central, or sub-marginal 

 exuvia. 

 B. Scale of male resembling scale of female in color and texture; only 

 slightly elongated. 

 C. Pygidium with 6 groups of circumgenital gland-orifices. — Com- 

 slockiella. 

 CC. Pygidium with less than 6 groups of gland-orifices. 



D. Chitinous processes much elongated. — Chrysomphalus. 

 DD. Chitinous processes smaller and shorter or wanting. — 

 Aspidiotus (Fig. 79). 

 BB. Scale of male white, delicate and carinated. 



C. Dorsal spinnerets irregular; exuvia usually sub-central. — Diaspis. 

 CC. Dorsal spinnerets in distinct bands; exuvia terminal in 2d 

 stage female and marginal in a.d\x\t.—Aiilacas pis. 

 AA. Scale of female elongated with exuvia at one extremity. 



B. Scale of male similar to scale of female, but smaller; five groups 

 of gland-orifices. — Lepidosaphes. 

 BB. Scale of both sexes white, that of male small, with parallel sides 

 and carinated. — Chionaspis. 

 BBB. Scale of female brown, that of male white and carinated.— fl^ewi- 

 chionaspis. 

 Chief Genera of the Coccina: 



A. Naked or covered only by a filmy secretion. 



B. Flat or slightly convex; dermis alveolate. — Coccus. 

 BB. Very convex, usually hemispherical; hard when mature. 



C. Dermis with coarse polygonal pitted areas. — Saissetia. 

 CC. Dermis microscopically tesselate, or appearing smooth. — 

 Lecanium. 



