1921] Smith: The Biology of the Chrysopide 35 
long on common aphids. It was thought that their particular 
kinds of food were not supplied, rather than that they took 
no food. It is therefore held that the economic importance 
of this family is much greater than has been usually stated. 
Fairly definite habitats were observed in the species studied. 
C. oculata and varieties are the most common and most widely 
distributed garden and field types. C. plorabunda is here our 
most abundant field species. C. nigricornis, C. rufilabris, C. 
harristt and C. lineaticornis are tree forms. C. harrisii is 
especially partial to pine, while J/ineatricornis and quadri- 
punctata seem to prefer oaks. C. nigricornis and rufilabris are 
found on a variety of trees, but maples probably predominate. 
Adults can best be collected by beating the bushes with a 
long stick and then catching the adults with a net as they fly 
out into the open. 
