2l6 AGRICULTURE OF MAINE. 



The parasites on this species seem to be increasing to quite an 

 extent. 



A large number of gipsy caterpillars were sent in by the field 

 force badly infested with the eggs of some species of Tachinid 

 fly, but for some reason the eggs did not hatch, or if they 

 did the maggots did not develop so as to destroy the cater- 

 pillars. It is presumed that the fly must have lacked instinct 

 and tackled the wrong host, getting hold of a customer too 

 tough for its progeny. 



The usual native parasites worked to some extent on the 

 brown-tail caterpillars, but not enough to cause any appreciable 

 diminution in their numbers. 



Several specimens of the two common Pimplas, P. pedalis 

 and P. conqiiisitor, emerged from the pupae of the brown -tail 

 moth. 



The parasitic fly, Frontina frenchii, is a very common enemy 

 of the cecropia. They resemble the common house fly so that 

 they would be easily mistaken for that species by the untrained 

 entomologist. 



The fly lays her eggs on the caterpillar. When these hatch 

 the minute maggots work their way into the body of their host 

 and there feed until they reach maturity. In the meantime the 

 larvae has reached its growth and spun its silken cocoon and 

 changed to the pupa stage. The maggots work their way out 

 of the pupa skin of the host and then change to the pupa state 

 within the inner cocoon of the cecropia. Here they remain 

 until they emerge as a perfect fly. We have counted thirty- 

 nine pupae of this fly in the cocoon of one cecropia caterpillar. 

 They succeed in keeping this insect somewhat under control. 



On February i6th a cluster of parasitic cocoons taken from a 

 cecropia were sent in. These hatched later and proved to be 

 Cry phis extrematis. 



Another parasite on the cecropia is the large single parasite, 

 Ophion bilineatus, which lays a single egg in the body of the 

 caterpillar. Upon reaching maturity this parasite forms a single 

 silken cocoon within the body of the host pupa and emerges the 

 following spring as an adult insect. These are more common 

 on the polyphemus. 



