October, ’23] 
outright: micromus life history 
455 
number of individuals during the course of the season. No great in¬ 
crease however was noted in the field. 
The adults probably oveiwinter. In support of this supposition three 
adults were taken in the field about the middle of October. These were 
placed in an outdoor cage and fed as long as aphids were obtainable in 
the open. On the twentieth of December two of the adults were still 
alive though freezing weather had been the rule for several weeks. 
When next examined on Jan. 2, these two were dead. The fact that 
they lived for a period of over two months in the open, under winter 
conditions would seem to indicate that some individuals would suc¬ 
cessfully overwinter. There is also a possibility that the pupa over¬ 
winters but the extreme frailty of the case seems to bean objection to 
this idea. 
No parasites have been reared from any stage of this species nor have 
any signs been noted that would indicate parasitism. As far as we have 
been able to find theie is also freedom from disease. 
Descriptions 
Since this work has been completed, the egg and all immature stages 
of Micromus posticus have been described and illustrated by Dr. R. C. 
Smith. (See Annals of the Entomological Society of America Vol. XVI, 
No. 2, p. 145-146 and Plate VII). The adult was first described by 
Walker in “The British Museum Catalogue of Neuroptera/’p. 283, 1853. 
Descriptions are also found in “A Synopsis of the Neuroptera of North 
America,” p. 204, 1861, by Hagen and in “The Transactions of the 
Amei'ican Entomological Society,” Vol. XXXII, p. 45, 1906, by Banks. 
In this publication it is mentioned as common throughout the eastern and 
southern United States. It is also stated that the larvae are found usu¬ 
ally on trees and that about ten days are required for their development. 
Economic Importance 
In the neighborhood of Columbus and Wooster during the past two 
summers this insect was of little economic importance in controlling 
aphids. Many counts of aphid predators taken in the field showed that 
in numbers this species was far in the minority. Attention may also 
be called to the low rate of feeding that is common to both predaceous 
stages. Banks (’06) states that they are common on aphid infested 
trees but the word common may be used by the collector in a far differ¬ 
ent sense from what it would mean if used by an economic entomologist. 
The number of eggs per female and the several generations per year would 
lead us to expect that the insect would increase rapidly during the 
