164 



Annals Entomological Society of America [Vol. XIII, 



VII. COCCID^. Life Cycle of Xylococcus betulcs. 



Fertilized Eggs. 



Male and Female 



1st Instar — Indistinguishable, active; an- 

 tennae stout, legs long, simple eyes large, 

 rostrum large. 



Male 



2nd Instar — Antennae and legs 

 stout, body segmentation distinct. 



3rd Instar — Legs and antennae 

 lacking. Much like 2nd instar of 

 female. 



4th Instar — Developing legs and 

 antenna present, rostrum lack- 

 ing, mesothorax shows traces of 

 future wing pads. 



5th Instar, Pupa — Developing legs 

 and antenncB long and stout, wing 

 pads broad. 



6th Instar, Adult — Compound eyes 

 large and projecting, legs stout, 

 antennae long, fore wings large 

 and functional, rostrum lacking. 



Female 



2nd Instar — Legs and antennae 

 lacking, simple eyes minute, 

 body without apparent segmen- 

 tation, rostrum functional. 



3rd Instar — Legs and antennas 

 lacking, simple eyes minute, body 

 without apparent segmentation, 

 rostrum functional. 



4th Instar — Legs and antennae 

 lacking, simple eyes minute, body 

 without apparent segmentation, 

 rostrum functional. 



5th Instar, Adult Female — Eyes 

 minute, rostrum lacking, legs and 

 antennse stout, body segmenta- 

 tion well defined. 



Young are produced oviparously. 

 (Adapted from Hubbard and Pergande.) 



