164 THE COCCIDAE 



is due to a sudden constriction which is limited to one side. The 

 distal end of the small tube bears a bouquet-like swelling. 



The adult females of the Lecaniinae usually produce eggs, 

 which are in most cases deposited under the concave ventral aspect 

 of the body or in an ovisac. Many species instead of depositing 

 their eggs give birth to living young. In such cases the ruptured 

 egg-shell and the young nymph may be extruded from the vulva at 

 the same tim^. Such ispecies diifer from the true oviparoas 

 species only in that the eggs are retained in the body of the female, 

 in the oviduct, until they hatch. Certain writers have made the 

 mistake of considering all species whose females give birth to living 

 young as reproducing parthenogenetically. While undoubtedly 

 many females are able to produce young without being fertilized, 

 it is quite likely a much larger number give birth to living young 

 from eggs that have been fertilized but are retained by the female 

 until after the eggs hatch. It is not impossible that many species 

 reproduce in both ways, that is, that certain females at certain 

 seasons reproduce pathenogenetically while other individuals re- 

 produce in the normal way. It is difficult to explain why there 

 should be an absence of males at certain times. The giving birth 

 to living 3^oung is not a proof of parthenogenesis. 



The eggs are ovoid in shape and white, yellow, or red in color. 

 Tliey are of common occurrence in those species which are naked 

 and where the ventral aspect is concave. In such cases the bod}' 

 of the female serves as a plate for covering and protecting the 

 eggs. The edge of the body adheres to the host-plant and, when 

 the body is raised, the space under it is seen to be packed with 

 eggs. The cerores located on the ventral aspect of the body ex- 

 crete a powdery wax, the amount varying with the species, which 

 is mixed with the eggs. 



The females in certain genera, as Pulvinaria, are naked until 

 they become adult and are ready to deposit their eggs. Thej^ then 

 begin to excrete a mass of doughy wax from the numerous cerores 

 located on the ventral aspect of the body. This wax is gradually 

 piled up as a pad or cushion until the caudal end of the body is 

 gradually raised from the host-plant and the body assumes a ver- 

 tical position. The insect is attached to the host-plant only by 

 the mouth-parts and the ovisac, which is often several times the 

 length of the body, and projects behind it. As a result the body 

 of the adult female after all the eggs are laid is often washed off 

 by the rain while the wax containing the eggs may remain for a 



