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JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 17 
Five species of European parasites 1 have been liberated in this country to date. 
At least one other species 2 looks very promising and will be liberated in 1924. Very 
satisfactory recoveries have been made of one species ( Exeristes roborator Fabr. 
The parasitism of European corn borers by native parasites is negligible 
at the present time except in the case of the egg parasite Trichogramma 
minutum Riley, which fluctuates greatly from year to year. Its highest 
parasitism comes too late in the season to give best results, but in a year 
like 1923 the cold dry summer delayed the host and was very favorable 
for the egg parasite. Collections from 24 towns in - Massachusetts all 
made rather late in the 2nd generation, averaged 61.4% parasitism by 
this species, which undoubtedly will help conditions in 1924 coming as 
it does in a season which has been especially unfavorable for P. nubilalis 
in New England. 
European parasites are collected and studied at our European 
Laboratory at Hyeres, France. The most promising species are sent to 
our laboratory in Massachusetts. Early shipments were entirely host 
larvae from which parasites were reared and liberated, while later work 
has developed more laboratory breeding methods which have proven 
most efficient. 
The status of the different imported species of parasites follows: 
Zenillia roseanae B. & B. a tachinid parasite of much promise attacks 
small host larvae and emerges just before pupation of the host. Its 
two generations synchronize perfectly with those of its host in France, 
and hibernation is as a second instar larva inside its living host. This 
species should have an extensive breeding campaign to furnish a suitable 
number for liberation. In 1920, 90 adults were liberated and in 1921, 
784. 
Eulimneria crassifemur, Thom, is a rather large hymenopterous 
parasite having two generations a year in France. It usually parasitizes 
small larvae while they are in feeding webs, and hibernates as a full fed 
larva inside a very compact cocoon. Thirty-one were liberated in 1920, 
4,968 in 1921, and 733 in 1923. 
Angitia ( Diodes ) punctoria Roman is a very effective summer 
parasite in Italy. It is very similar to Eulimneria in appearance and 
habits, except that it parasitizes free crawling larvae as well as those in 
feeding webs. Only 10 were liberated in 1921, and 168 in 1922. We 
tachinid Zenillia roseanae B. & B. Hymenoptera Eulimneria crassifemur 
Thom., Angitia ( Diodes) punctoria Roman, Habrobracon brevicornis Wesm Exeristes 
roborator Fabr. 
2 Microgas ter tibialis Nees. 
