342 FOREST ENTOMOLOGY. 



character of the anal lobes, which, although varying in degrees of 

 development, are always present. 



" In Dacfi/lojnus the ovisacs are usually formed of loose, white, 

 flocculent secretion, often quite devoid of form, and aggregated in 

 masses on the food-plant. 



"In Cryjjtococcus the ovisacs are also felted, and often so thickly 

 packed together as to completely cover the bark of the tree. 



"The males are characterised by the comparatively short and 

 somewhat complex structure of the genital armature. 



" The male puparia are generally felted." ^ 



Synopsis of the Genera. 



A. Adult females stationary, enclosed in a glassy or horny fringed 



ovisac (test) . . . (I.) Asterolecanium (1). 



B. Adult females active, covered with mealy secretion, not enclosed 



in ovisac, 

 (a) Female antennae of eight joints . (II.) Dactylopius (2). 

 BB. Adult females enclosed within ovisac at gestation. 



(a) Female antennse of nine joints . (III.) Pseudococcus (3). 

 {b) Female antennae of six, rarely of five or seven, joints 



(IV.) ElPERSIA (4). 



G. .Idult females stationary, living from the earliest stage within the 

 ovisac ; antennse and legs rudimentary or absent. 

 (a) Anal orifice of adult female with four spiny hairs 



(V.) Cryptococcus (9). 

 (h) Anal orifice of adult female with six long hairs 



(VI.) Antonina (7). 

 CO. Antenmy and legs present ; anal orifice with six flattened hairs 



(VII.) Apterococcus (S). 



D. Anal lobes of adult female very large, body with long marginal 



or dorsal spines . . . (VIII.) Eriococcus (5). 



E. Body of adult female with numerous short conical spines 



(IX.) Gymnococcus (6). 



The above " synopsis " is copied in full from Newstead's ]\Iono- 

 graph, vol. ii. ; and though all the genera are not arboreal in their 

 habits, it is important that the student, more especially a horticultural 

 student, should study at least a typical species from each genus. 

 ^ Adapted from Newstead's Monograph. 



