253 
THE HABITS OF ELASMUS. 
By L. O., Howarp. 
Fig. 39.—Elasmus varius, male—greatly enlarged (original). 
The Chalcidid parasites of the genus Hlasmus Westwood differ so 
markedly in their structure from all of the other members of the family 
that they have been placed alone in a separate subfamily Elasminee. 
The most striking characters of these minute creatures are their greatly 
enlarged and flattened hind coxe, the large meso-postscutellum and 
the long marginal vein. They have also enlarged hind femora like the 
Chalcidine, except that they are more flattened, and they have flabellate 
antennée in the male as in certain Eulophine. The species are rather 
rare in Europe but seem to be more common in this country. Differing 
from other characteristic and restricted groups these insects vary 
greatly in their host relations. They attack, generally, two classes of 
insects: small Lepidopterous larvee and Microgasters. The European 
species have been reared from Psyche graminella, Epichnopteryx helix, 
Cecidomyia rosaria, and a gall on Populus tremuloides. Thomson makes 
the general comment upon the species of this genus that they are para- 
Sitic upon Microgasters. 
The four species firstreared in this country were H. varius How., #. 1- 
gripes How., E. pullatus How., and E. tischeriw How. All of these were 
indicated in the notes of the Division as having been reared from Tineid 
leaf-miners, but it is interesting to note that in the cases of H. varius 
and H. pullatus Microgasters were also bred from the host insects. 2. 
albicora How., was found in the breeding jar with eggs of Limenitis dis- 
ippus, and may come either from a leaf-miner in the Willow leaves upon 
which these eggs were laid or from the Microgaster which commonly 
