1342 Roger C. SmitH 
through the shipping of hay, grass, logs, trees, shrubbery, and the like. 
Cocoons occur on various parts of these and may readily be shipped 
even to considerable distances. Professor C. R. Crosby found fourteen 
chrysopid eggs on the window of a moving train, and this suggests a 
ready means of spread. Adults may enter open box cars during the 
day and be transported to a considerable distance. 
ECONOMIC IMPORTANCE OF THE FAMILY 
Both larvae and adults of all our species of Chrysopidae are 
distinctly beneficial. The only instance on record of this family’s doing 
any harm was in California, where the larvae were reported by Essig 
(1911) as destroying the larvae of ladybird beetles which had been 
introduced to combat scale insects. During the course of these rearings 
several species of coccinellid beetles were successfully reared in the same 
vials with chrysopids, but there were usually some aphids present. 
Chrysopid larvae are occasionally an annoyance to man by their bit- 
ing, which suggests a pin prick, and by their crawling over his person. 
This occurs most frequently under trees or in fairly dense vegetation. 
The tree and shrub chrysopid species are most commonly the source of 
this annoyanee, but any hungry, grown, third-instar larva appears to be 
capable of piercing the skin and sucking some blood if not disturbed 
(Marchand, 1922). . 
The chief contribution of the Chrysopidae to human welfare is 
their destruction of plant lice during the summer and autumn months. 
They do not appear early enough in the year, nor are they present in 
sufficient numbers, to appreciably check fruit injury by plant lice or to 
reduce early spring outbreaks of aphids such as that of the pea aphids 
on alfalfa in Kansas early in 1921. But as summer progresses, the 
tree-inhabiting species become sufficiently numerous to take an important 
part in combating the woolly apple aphis on elm, the painted maple 
aphis, the maple Phenococecus, the apple leaf hopper, and similar pests. 
Aphids attacking cereal and forage crops are preyed upon by Chrysopa 
oculata, C. plorabunda, and C. rufilabris, chiefly. These species are 
usually present in clover and alfalfa fields, sorghum fields, and corn- 
fields, sometimes in great numbers. While it is the larvae that are 
generally seen devouring the plant lice in the field, nevertheless there is 
no doubt that the adults of our common species regularly prey upon 
plant lice, with the possible exception of C. plorabunda, and thereby 
increase the importance of this family economically. 
One is likely to give the Coccinellidae and the Syrphidae some of 
the credit for aphid destruction which is really due to the Chrysopidae, 
