1336 Roacer C. Smiru 
HIBERNATION 
The majority of the species of Chrysopidae winter as prepupae 
within their silken cocoons. It is usually stated that they winter as 
pupae, but by opening cocoons monthly during the winter, it was found 
that they remain prepupae. Chrysopa plorabunda normally overwin- 
ters as adults in Kansas. In the mild winter of 1920-21, this species 
was active almost all winter and could be taken in numbers on warm, 
sunshiny days. During the more severe winter of 1921-22, none could be 
found flying in the open nor caused to fiy up by beating. C. interrupta 
was reported by Banks (1915) as hibernating at Mount Vernon. Adults 
of C. vulgaris have been reported by McLachlan (1869) as wintering in a 
hornet’s nest. C. flava has been reported by several writers as wintering 
in the adult stage. 
One species, C. cockerelli, was found to winter as practically grown 
larvae. Larvae of this species were kept alive over winter without 
food in an attic and in a eave. Furthermore, an overwintering larva 
was found on April 4, 1921, in an apple orchard under a piece of bark. 
In the South, Chrysopidae breed continuously through the year. 
Repeated attempts to winter eggs, larvae, and adults of species 
other than those previously mentioned have failed. Adults of C. rufi- 
labris, C. quadripunctata, and C. harris were kept alive until November 
and December in Virginia in outdoor protected cages, but they finally 
all died. Immature larvae of our common species die if they are not 
fed, and when they are fed they go on to maturity and spin cocoons in 
which they winter as prepupae. 
During the winter cocoons of the tree-inhabiting species may be 
found in crevices of the bark on maples, oaks, and elms, on leaves in 
heaps along hedgerows, and in similar protected places according to the 
habits of the larvae. 
Discoloration in hibernating adults 
Overwintering adults are usually much reddened, and their green 
color is largely replaced by brown as a result of the cold and from lack 
of food. Banks (1915) reported discoloration in Chrysopa plorabunda. 
Kolbe (1893) stated that the green color of chrysopids was due to 
chlorophyll, and ascribed the color change of C. vulgaris in the fall and 
after death to factors causing a comparable change in the leaves in 
autumn. 
Specimens of C. rufilabris taken at Milwaukee on September 27, 
1918, soon after the first frosts, had an elaborate reddish color pattern 
over the entire body, and the wings were a decided brown. This discol- 
