A STUDY OF THE BIOLOGY OF THE CHRYSOPID. 
By RoGerR C. SMITH, 
Assistant Professor, Kansas State Agricultural College. 
There is much of biological interest to be found in the life 
history of the Chrysopide. The group is a very homogeneous 
one, varying little in morphology and habits. They are of wide 
distribution, and one or more species in all localities visited 
can be’ appropriately classed among the most common insects. 
Several species are somewhat rare and difficult to collect, hence, 
the biological data available concerning these is still somewhat 
fragmentary. This brief paper is a summary of a large detailed 
paper, the publication of which has been unavoidably delayed.* 
A full report of this work is now awaiting publication as a thesis 
for the doctorate in the memoir series of the Cornell University 
Experiment Station. This report will be amply illustrated. 
LIFE CYCLE. 
The total life history of the Chrysopide requires a period of 
approximately 25 to 50 days. Cold weather in the late fall or 
early spring greatly retards growth and development. From 
4 to 12 days were required for embryonic development, the eggs 
hatching in midsummer in four to six days after deposition. 
The first molt occurs in three to seven days, or, in cool weather, 
in 11 days after hatching. The second molt occurs at an interval 
of two to seven days, the majority molting three and four days 
after the first molt. The third instar may vary greatly in 
time. Sometimes it is much prolonged, especially if food is 
scarce. But from the second molt to spinning the cocoon, 
there is usually a period of 4 to 10 days, the majority requiring 
five or six days. The final larval molt to the pupa occurs 
within the cocoon 5 to 12 days after spinning. However, in 
* The writer has been studying the Chrysopide intensively for about five 
years. During this time some or all of the immature stages of fifteen species 
have been seen. Collections and rearings have been made at Ithaca, N. Y., where 
this work was begun under the direction of Professor James G. Needham, of 
Cornell; at Dayton, Ohio; at Milwaukee, Wisconsin; at Charlottesville, Virginia, 
and at Manhattan, Kansas. Through the courtesy of Dr. Nathan Banks, the 
Fitch, Hagen and Banks’ types at the Museum of Comparative Zoology, at Cam- 
bridge, Mass., were studied. 
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