2G2 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 
dopterotu Karoo, and we have bred it from seven widely different species. (5) Spilo- 
chains maria (Riley). This species, while parasitic on Thyridopteryx, is more partial 
to the large silk-spinning caterpillars, as we have reared it from the cocoons of 
all of our large native Silk-worms. (C) Pteromalus sp. This undescribed Chalcid is 
Fig. 100. — Pimpla conquuitor : a, larva; b, head of do. from front; c, 
pupa; d, adult female (hair line indicating natural size); e, end of male 
abdomen from above ; /. same from the side — all enlarged. (After Riley.) 
found very abundantly in the Bags, but may be a secondary parasite. (7) Dinocarsis 
thyridopterygis Ashmead.* This parasite was bred from the bags in Florida by Mr. 
William H. Ashmead, who believes it to be parasitic on the eggs. (8) Tachina sp. 
Fig. 101.— Hemiteles thijridopterigis : a, male ; b, female; 
c, sack of bag- worm cut open, showing cocoons of parasite, 
natural size. (After Riley.) 
"We have bred a large bluish Tachinid from the bags. Its eggs are commonly at 
tached to the bags externally, near the neck, and the young larvae, on hatching, 
work their way into the case. They frequently fail, however, to reach the Bag- 
worm. 
34. THE WHITE- SPOTTED TUSSOCK-MOTH. 
Orgyia leucostigma (Abbot and Smith). 
The caterpillar of this moth is now and has been for some time a 
most grievous pest in our cities. We have observed it on Boston 
Common, where for years, as stated by the late Dr. Brewer, it has been 
injurious to the elms, as well as the maples. Though the species ex- 
tends from Maine aud Canada to the Southern States, it is most abun- 
dant in the New England and Middle States, and more common in 
* Mr. Ashmead's description (Canadian Eutomologist, XVIII, No. 5, p. 97, May 
(1866), shows that this species can not belong to Dinocarsis, as limited by Mayr. 
