73 



many minute branches. The mouth parts, as in most maggots of 

 this character, consist of two minute, sharp, black rasping organs, 

 which answer the purpose of mandibles and which project slightly 

 from the head. The length when mature is one-fourth of an inch. 



The pupa r ium or quiescent stage is represented by fig. IT, d. It is 

 dark brown in color and of moderate ly strong consistency. 



The distribution has been practically given in the list of localities 

 in which injuries have been noted. It might be defined as extending 

 from Massachusetts and New York southward at least to the District 

 of Columbia, and westward to northern Michigan. 



LIFE HISTORY. 



The life economy of this species is fairly well understood, owing 

 chiefly to the observations of Mr. Slingerland, but some details remain 

 to be observed. 



The egg is deposited just underneath the skin by means of the ovi- 

 positor, may be placed in an}- portion of the cherry, and the egg scars, 

 although not in crescent shape like those of the plum curculio, are 

 easily discovered. Throughout the northern range of this insect, 

 where it is most injurious, oviposition continues over a considerable 

 period, from June until into August, or probably as long as cherries 

 are to be found. Unhatched eggs have been discovered as late as 

 August 16. The exact period of the egg stage has not been observed, 

 but it will probably extend from three or four days to a week or 

 ten days, according to temperature. Soon after hatching the larva 

 penetrates to the vicinity of the pit, feeding on the flesh and forming 

 a rotting cavity similar to that made by the larva of the plum curculio. 

 As a rule the maggots attain maturity simultaneously with the ripen- 

 ing of the cherries, and ihej thus find their way to the consumer. It 

 has been observed that few affected cherries fall from the trees, in 

 which respect this species differs from the apple maggot. The mag- 

 gots, therefore, usually drop to the ground, where in a few days they 

 form the puparium stage. 



The species is without doubt single brooded, even as far south as 

 the District of Columbia, and probably as far as its southern range 

 extends, and the pupal period therefore consumes about eleven months 

 of the } T ear, this stage being passed in a cell within about an inch of 

 the surface of the ground. As it frequently happens that infested 

 cherries show little exterior effects of damage they are shipped from 

 one locality to another, and the insect can thus readily obtain a foot- 

 ing in new localities; but being a native species,, this is a matter that 

 probably has little importance. 



As to the varieties of plants affected, thus far there is little doubt 

 that the insect affects chiefly sour or subacid varieties, particularly 

 the Morello and Montmorency varieties, but the Downer and black 



