The Scale Insects 



Fig. 147. — Common hot-house 

 mealy-bug, Dactylopius 

 citri. (After Comstock.) 



out life. The adult female insect then 

 is a wingless, motionless, degraded, 

 and for all practical purposes legless 

 and eyeless creature. She seems 

 simply an animated drop of proto- 

 plasm enclosed in a skin. In the 

 armored scales she is absolutely leg- 

 less and eyeless. The mouth-parts 

 through which she derives nourish- 

 ment remain functional and become 

 enlarged from molt to molt. Her 

 body becomes swollen with eggs or 

 young and as soon as these are laid or born she dies. 



The life of the male differs radically from that of the female. 

 Up to the second molt the development remains practically 

 parallel in the two sexes, but after this molt the male larva trans- 

 forms to a pupa in which the organs of the perfectly developed 

 fledged insect become apparent. This change may be undergone 

 in a cocoon or under a male scale. The adult male, which issues 

 at about the time when the female becomes full grown, is an 

 active and rather highly organized creature with two broad func- 

 tional wings and long vibrating antennae clothed with hairs. 

 The legs are also long and stout. The hind wings are absent but 

 are replaced by rather long tubercles to the end of which is 



articulated a strong bristle hooked at 

 the tip and fitted into a pocket on the 

 hind margin of the wings. The eyes 

 of the adult male are very large and 

 strongly facetted. The mouth-parts are 

 absent and curiously enough their place 

 is taken by supplementary eye spots or 

 simple eyes (ocelli). The function of 

 the male seems simply to find the 

 female, to fertilize her and then die. 



The number of generations in scale 

 insects varies greatly and no general 

 statement can be made. 



The scale insects found in the 

 United States belong to three large 

 groups, the most important and the 

 253 



Fig. 148. — Long-tailed mealy 



bug, Dactylopius longifilis. 



(After Comstock.) 



