THE BIoLoGy OF THE CHRYSOPIDAB 1337 
oration was brought on gradually during the fall of 1918 in specimens 
of C. rufilabris and C. quadripunctata which were placed in outdoor 
cages and fed on a weak sugar solution. As the cold weather came on, 
the discoloration became gradually more pronounced. Discolored adults 
of C. plorabunda are very common in Kansas in the fall and spring. 
The reddening appears with the first cold weather in the fall and per- 
sists until the adults begin to take food in the spring. Some specimens 
retain a little of the green, but the majority lose most of the normal 
coloration. Both males and females overwinter and thus become dis- 
colored. 
It has been found that at any time during the winter the discolored 
adults of C. plorabunda may be brought into the laboratory and the nor- 
mal green color restored. It appears that food is more important than 
temperature in this restoration, though this species has not been observed 
to take any food in confinement other than water, weak sugar solution, 
plant sap, and, less commonly, crushed aphids. The coloration has been 
restored in from one to two weeks by feeding water alone, or sugar solu- 
tion, while the insects were confined in the laboratory. 
FIRST APPEARANCE OF THE ADULTS IN THE SPRING 
The time of the first appearance in the spring varies with the 
manner of overwintering and the elimate. Adults of Chrysopa plora- 
bunda have been taken throvghout the winter in Kansas. At Charlottes- 
ville, Virginia, the first adult of C. oculata was seen on March 20, 1919; 
at Ithaca the first adult was seen the first week in May, 1916, but it is 
doubtful whether this was among the first to emerge. Adults of C. quadri- 
punctata and C. nigricornis were taken the latter part of May, 1921, in 
Kansas, and in June, 1917, at Ithaca and in Kansas. It has been 
observed for four years that June is the earliest date when a variety of 
Chrysopidae has been taken by collecting. Adults were obtained during 
all the winter and spring months by bringing overwintering cocoons 
indoors, into a room of fairly constant temperature. Some individuals 
pupated promptly, while others made apparently no change for a month 
or more. Some prepupae died when brought indoors in the course of 
these studies, but pupae very rarely died in cocoons. 
FACTORS REDUCING THE NUMBER OF INDIVIDUALS 
Several papers dealing with the parasites of the Chrysopidae have 
been published. Howard (1888), Girault (1907b), and McGregor 
(1917) have given lists of parasites. Moffat (1901) discusses egg para- 
sitism but lists no species. So far three egg parasites, one larval parasite, 
