The Grape-Berry Moth. 117 



characteristic cocoons on the leaves, Hke the earUer broods. Our 

 observations indicate that the insect always passes the winter in the 

 pupa state in its cocoon on the fallen leaves near the vines. 



The European grape-berry moth has three broods in Italy and its 

 habits are very similar to the American insect during the growing 

 season. But in autumn the European caterpillars, instead of making 

 their hibernating cocoons on the leaves or in the fruits, as they do in 

 summer, go onto the trunks of the vines and the stakes or trellis posts, 

 where imdemeath the bark they make their thicker, winter cocoons. 

 We failed to find any hibernating cocoons of the American insect in 

 New York vineyards except on the fallen leaves. 



The Natural Enemies of the Grape-Berry Moth. 



Fortunately for the vineyardist, we have discovered that the grape- 

 berry moth has many enemies among its own kind, which play a very 

 important part in its "ups and downs." Undoubtedly these insect 

 enemies, aided by winter weather conditions, are largely responsible 

 for the comparatively small size of the spring brood of this grape pest. 



In August, 1903, several caterpillars were found in the grape- 

 berries that were being attacked externally by a whitish maggot, 

 which soon spun a little, white, silken cocoon after sapping the life 

 of its victim. From several of the cocoons kept in our breeding cages 

 during the next winter, there emerged in May and June two kinds of 

 Httle parasitic flies instead of the expected grape-berry moths. Then 

 in the spring of 1904, we found in the webbed blossom-clusters 

 several cocoons of another parasite, which had doubtless destroyed 

 the caterpillars feeding on the blossoms. Later that season, we 

 found that many of the caterpillars of the second or summer brood 

 never developed into the moths, for little parasitic flies came from their 

 cocoons in August. 



The grape-berry moth is therefore beset by insect enemies during 

 the development of each brood and at all seasons of the year. We 

 have bred the unusually large number of six different kinds of para- 

 sitic flies, which must materially help the vineyardist in his warfare 

 against his enemy. This was a surprising discovery, for heretofore 

 only a single enemy of this grape pest had been recorded in America.* 



*Two parasites, a Pimplid {Phytodietus pleuralis Cress.) and a Braconid (Bracon 

 vernoninae Ashm.) have been recorded (Insect Life, II, 349, and III, 404) on 

 Eudemis botrana in this country. But the former was bred from tulip-tree 

 and the latter from seed capsules of Vernonia; and the host insects feeding on 

 these plants are now believed to be distinct species from either the European or 

 the American grape-berry moths. The one working on tulip-tree leaves is de- 

 scribed on page 58 as Polychrosis liriodendrana by Mr. Kearfott. However, it 

 is quite probable that these two parasites also include the American grape-berry 

 moth among their hosts; and thus should be added to the list of its insect enemies. 



