THE TIMOTHY STEM-BORER. g 
PARASITIC ENEMIES. 
This insect is apparently a very attractive host. Three species 
of parasitic Hymenoptera have been reared from it, all of them 
new, representing three genera—two braconids and one a chalcidid. 
Messrs. H. L. Viereck® and J. C. Crawford? have kindly described 
these parasites, giving them the following names: Heterospilus 
mordellistene Vier., Schizoprymnus phillips: Vier., and Merisus 
mordellistene Crawf. The descriptions appear elsewhere over the 
names of their respective authors. 
In May of this year, Mordellistena ustulata was found to be very 
abundant at Wilmington, Ohio, in timothy; material was collected 
and sent in to the laboratory at La Fayette, Ind., for rearing. Two 
species of parasites were reared from it, Heterospilus mordellistenz 
and Merisus mordellistene. Schizoprymnus phillipsi and Heterospilus 
mordellistenze were reared from material collected at Richmond, Ind., 
in 1906 and 1908, respectively. The latter species and Merisus 
mordellistene were reared at La Fayette, Ind., in 1910. 
It is very probable that the parasitic enemies keep the beetles 
pretty well in check and that this accounts for the appearance of 
the beetles in small numbers only in any given locality. 
REMEDIAL MEASURES. 
As this insect has never appeared in destructive abundance, so far 
as known, there has been no occasion to devise means of combating it. 
If a serious outbreak should occur, however, a short crop rotation 
should be adopted, allowing a field to remain in timothy sod not 
more than two or three years, thus preventing this stem-borer from 
becoming well established. The borders of the fields and waste places 
should be mowed frequently during the months of June and July. 
If this is done, the larve will not be able to reach maturity. 

4 Proceedings of the U. S. National Museum, vol. 39, pp. 401-408, 1911. 
5 Proceedings of the Entomological Society of Washington, vol. 12, no. 3, p. 145, 
1910. 
O 
