The Golden-Eyed Lace-Winged Flies 



The insect transforms to pupa within the interior of a white 

 spherical, silken cocoon, which is very characteristic in appear- 

 ance, and the adult escapes through a circular hole to which the 

 cap remains attached like a lid. 



The golden-eyed lace-winged flies are among the most im- 

 portant enemies of the injurious plant-lice which swarm upon 

 many valuable plants especially in the early part of the summer. 

 The mother fly lays her eggs where possible in the midst of 

 colonies of plant-lice, and these are rapidly swept out of existence 

 after the eggs are hatched. 



A few of these lace-winged fly Iarva2 have the same habit 

 which we have described as occurring with the Hemerobiids, of 

 covering themselves with the skins of their victims. Hubbard 

 has studied a species which feeds upon bark-lice, tearing the 

 scales loose from the bark and devouring the soft contents, and 

 then adding a portion of the debris to the load on its back. 



Unfortunately, these beneficial lace-winged flies are subject 

 to the attacks of certain parasitic chalcis flies which sting their 

 cocoons. The species of the interesting genus Isodromus seem 

 to confine their attacks exclusively to the cocoons of lace- winged 

 flies. 



Life History of a Golden-Eye 



(Chrysopa oculata SayJ 



This is one of the commonest species in this group, and is 

 often mentioned in books on economic entomology as destroying 

 plant-lice and other injurious insects. The only observer to de- 

 scribe its life history with any detail, however, is Marlatt, from 

 whose observations the following statements are drawn. 



The eggs, instead of being deposited in rather large groups, 

 as is the case with other species, are distributed almost invariably 

 singly upon the leaves of trees, and rarely two are found together 

 upon the same stalk. The young larva cuts off the upper end of 

 the egg and on emerging crawls down the stalk and begins its 

 search for food. Approaching the egg of the pear tree Psylla, 

 for example, it immediately grasps it between its long curved 

 mandibles and rapidly extracts the juicy contents. This is done 

 with great celerity, the dry shell is cast aside, and the whole 



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