REPORT OF FIELD AGENT^ GYPSY MOTH WORK. I23 



shells and emerge as very small black fly-like insects just be- 

 fore the new lot of gypsy eggs are laid in late summer. This 

 parasite is a very satisfactory enemy after it becomes well es- 

 tablished. It will destroy from one-fifth to one-third of the 

 gypsy eggs but it is so small that the spread is very slow and 

 for this reason we are compelled to put out new colonies quite 

 near together to make any impression on the gypsy infesta- 

 tions. One thousand gypsy eggs containing parasites are used 

 for each colony; these are placed in a small tin can with holes 

 in the side through which the insects can escape and the can 

 is nailed to the side of a tree. These colonies are placed on 

 both sides of roads at quarter mile intervals wherever there 

 are a sufficient number of gypsy moth egg-clusters present to 

 warrant such planting. 



Last spring was the first season that colonies of this parasite 

 were put out in Maine. Following the plan just outlined the 

 towns of Kittery, Eliot, York, South Berwick, Berwick, North 

 Berwick, Wells, Sanford, Kennebunk, Kennebunkport, Dayton, 

 Saco and Biddeford were colonized. 



APANTEEES EACTEICOLOR. 



This parasite attacks both the brown-tail and gypsy moths. 

 It spends the winter as a small maggot inside of the young 

 brown-tail caterpillars and as soon as these emerge from the 

 webs in the spring, begins feeding on the body contents of its 

 host. It becomes full grown and emerges to spin a small white 

 cocoon about the last of May, killing the caterpillars at the 

 same time. In a short while the adults, which are small black 

 fly-like insects, ennerge from these cocoons and attack the 

 young gypsy caterpillars, killing them in the same way. Shortly 

 after the young brown-tail caterpillars hatch from the eggs in 

 late summer they are attacked by the adults of this parasite; 

 eggs are deposited in them and these hatch to produce the small 

 maggots mentioned above as passing the winter. 



This parasite was first recovered in Maine from the town 

 of York in the spring of 19 12, probably having spread there 

 from some one of the towns in New Hampshire. By 1913 it 

 had spread as far north as Waterboro and Saco. That 

 year the first attempt was made by the authorities of Maine to 



