52 OUR SHADE TREES AND THEIR INSECT DEFOLIATORS. 



In several instances batches of eggs of this moth were parasitized, and 

 instead of producing young caterpillars the} r brought forth the tiny 

 insects of this species. The batches of parasitized eggs were found 

 July 27 upon the leaves of Sunflower, and August 18 upon leaves of 

 Willow; judging from these dates it was the second brood of moths 

 that had deposited them. There can be no doubt, however, that eggs 



Fig. 23. — Telenomas bijldus (greatly enlarged). 



produced by moths emerging from their cocoons in early spring had 

 been parasitized as well. The female Telenomas was also observed, 

 August 2, busily engaged in forcing its ovipositor into the eggs, and 

 depositing therein. The female insect is so very intent upon its work 

 that it is not easily disturbed, and one can pluck a leaf and apply 

 a lens without scaring it away. The eggs soon hatch inside the large 

 egg of the moth, and the larvae produced soon consume the contents. 

 This egg-parasite is a very useful friend, nipping the evil in the bud, 

 so to speak. 



Meteor us hyphantrice Riley. — "This parasite (Fig. 24) has performed 

 very good services during the caterpillar plague and has done much to 

 check any further increase of the Web-worm. During the earlier part 

 of the summer this insect was not very numerous, but sufficient proofs 

 in the form of empty cocoons were observed to indicate at least one 

 earlier brood. Towards the end of September, and as late as the loth 

 of October, very numerous cocoons of a second brood were formed; 

 they could be found in all situations to which the caterpillar itself had 

 access. But the great majority of them were suspended from the 

 trunks and branches of trees, and chiefly from near the base of the 

 trunk. Each cocoon represents the death of one nearly full-grown cat- 

 erpillar, since the latter harbors but one larva of the parasite.* A 

 careful watch was kept to see how such a suspended cocoon was formed, 



* In only one instance the cocoon of this parasite was found inside that of its host. 



