NEUROPTERA 



87 



the most important of nature's agencies for keeping these 

 plant pests in check. 



Its mouth parts are very peculiar. On first glance it seems 

 to have one pair of big pincher-like sharp-pointed jaws, but 

 each half of the pincher is a sucking tube. It sucks the blood 

 of an aphid through two straws, so to speak. The mandible 

 and the lacinia of the maxilla of each side are prolonged 



Fig. 32. — The lace-wing fly, Chrysopa. Two adults , a larva below on the stem and a cocoon 

 containing a pupa under the leaf (from Kellogg.) 



together, channelled and closely united and pointed at the 

 tip to make this grasping, puncturing and sucking pair. If 

 living larvae, swept from the vegetation, be placed with a 

 colony of aphids, the use of these jaws will be quickly demon- 

 strated. 



