124 ECONOMIC ENTOMOLOGY 



AA. With a strong cottony secretion; secreting an ovisac; body more or less 

 chitinous without dorsal patches of secretion. — Ptilvinaria. 

 Chief Genera of the Daclylopina: 



A. Female globular or reniform, in a hard shell; larva fringed with spines. — 

 Kermes. 

 A A. Female not as above; anal ring with eight hairs. 



B. Adult surrounded by secretion but dorsally naked. — Gossyparia. 

 BB. Adult forming a cottony sac; caudal lobe long. — Eriococcus. 

 AAA. Female with soft powdery oval unarmored body; anal ring with six hairs. 



B. Antennae normally with 8 segments, sometimes 7; tarsus not toothed. — 

 Pseudococcus (Fig. 81). 

 BB. Antennae normally with 9 segments; tarsus toothed. — Phenacoccus. 



Scale insects are typically bark-lice, being minute sucking insects 

 covered with a mealy or cottony waxy secretion. Some, like the Mealy 

 Bugs, secrete a cottony material; some, like the Lecaniums, secrete 

 a waxy hard continuous layer which forms a protection for the back; 

 while others, like the San Jose Scale and the Oyster Shell Scale, pos- 

 sess true scale-like coverings, composed partly of a waxy secretion 

 and partly of moulted skins, beneath which the insect lives. 



For a short time after birth Scale insects crawl about, but soon they 

 settle on the bark or leaf and begin sucking the sap. After a few 

 moults the females lose their legs, eyes and feelers. The male adult 

 insect is, as a rule, an active 2-winged insect with legs, eyes, feelers, 

 but no mouth. In most species the females lay eggs (oviparous), 

 but in a few the young scale insects are born alive (viviparous), i.e., 

 the eggs hatch within the body of the mother. 



(Consult Comstock's republished papers, Bull. 372, Cornell; the 'Coccidae of 

 Ohio" by Sanders; "Some Scale Insects of Mississippi" by Herrick; "The 

 San Jose and other Scale Insects" by Lochhead; "Coccidae of Indiana" by 

 Dietz and Morrison; and Bull. 6, Tech. Series, Div. Ent., U. S. Dept. Agr.) 



Hard Scales (Diaspin^) 



Following are the most common economic orchard forms: ^ 



Oyster Shell Scale (Lepidosaphes ulmi Linn.). — (Consult Farmers' 

 Bulletin 723, U. S. Dep. Ag.) A cosmopoHtan insect of European 

 origin and one of the most common pests of the orchard and of shade 

 trees 'and shrubs. Single-brooded in the North but double-brooded in 

 the Middle and Southern States (Fig. 79). 



