APANTELES MELANOSCELUS GIPSY-MOTH PAPvASITE. 25 



same summer some interesting data were obtained from a medium- 

 sized oak tree near the Gipsy Moth Laboratory at Melrose Highlands. 

 This tree had many gipsy-moth egg clusters on it which had not been 

 creosoted during the winter, so that on this particular tree there 

 was a much heavier infestation of gipsy-moth larvse than on any of 

 the other trees in the vicinity. As the summer progressed, cocoons 

 of A. melanoscelus began to appear in surprisingly large numbers. 

 When most of the first-generation maggots had issued and spun their 

 cocoons, the underside of nearly every crotch on the tree was covered 

 with Apanteles cocoons (PI. II, C). 



There were 5,140 first-generation cocoons collected from this tree. 

 A few cocoons could not be reached and some had blown away before 

 the collection was made. Later in the season 511 second-generation 

 cocoons were taken from the tree, making a total of 5,651 cocoons of 

 A. melanoscelus removed from this tree. Although heavily infested 

 the foliage on the tree was not damaged much by the feeding of the 

 gipsy moth larvae and very few gipsy-moth pupse were found on the 

 tree. These data are not given as a sample of the condition of the 

 trees in Melrose Highlands in 1916, but the figures are interesting 

 and show what happens under some conditions. Occasionally large 

 oak trees have been seen in other towns on which it was estimated 

 there were from 6,000 to 10,000 cocoons. 



In 1918 this parasite was found in large numbers over an area of 

 several acres of woodland in Cohasset. In 1919 and 1920 it was 

 found abundantly in small areas in Hampton, N. H., and in the 

 following towns in Massachusetts: Beverly, Quincy, Weymouth, 

 Cohasset, Scituate, Marshfield, and West Boylston. 



CONCLUSION. 



Apanteles melanoscelus has been present in New England since 

 1911 and is now firmly established. It is spreading rapidly from 

 the colonies which have been liberated and is increasing in spite of 

 its being heavily parasitized by secondaries. 



The fact that A. melanoscelus is able to complete its life cycle on 

 several native insects adds considerably to its value as an introduced 

 parasite and makes its permanent establishment more certain than 

 if the gipsy moth were its only host. 



This parasite has two generations each year on the gipsy moth 

 and is very abundant in many small areas. It gives promise of 

 becoming one of the most valuable of the imported parasites. 



