June, '151 RICHARDSON: THE CORN-FEEDING SYRPHUS FLY 339 



report it from Griggstown, Somerset County, N. J., and Jacksonville, 

 Fla. In the former locality, the larvae were feeding on pollen from 

 corn; in the latter they were attacking the corn tissue at the base of 

 the leafstalk and were even found in soft discolored places in the stalk. 

 Mr. Ashmead, who made the field observations at Jacksonville, states 

 that he did not observe any of the larvae feed upon pollen in that local- 

 ity. In 1889 the same authors ^ published a letter from a correspond- 

 ent at Cadet, Mo., in which damage to corn by the larvae of M. poUta 

 was reported. In this locality, the informant found the larvae 

 between the bases of the leaves and the stems where they caused the 

 lower leaves to wither and dry up. 



The late Dr. John B, Smith cites an infestation in evergreen sweet 

 corn at Cologne, Atlantic County, N. J.^ The larvae were found be- 

 tween the leaves and the stalks of the corn. Specimens kept in the 

 laboratory lived apparently upon the moist exudation from the surface 

 of the stalk where it envelops the leaf sheath. No pollen was given 

 them, but they reached maturity successfully. 



Sanderson in 1900^ discovered this species in corn at Newark, Del. 

 The larvae were often found in the staminate flowers, in the axils of 

 the leaves, in the silk and wherever else pollen had lodged. Puparia 

 were observed among the florets on the tassels. Although the larvae 

 were very abundant, no injury to the leaves or stalks could be 

 detected. 



Folsom ^ has given the only account which the writer has seen of 

 the aphidophagus habits of the corn-feeding Syrphus fly. He says, 

 ^' Mesogramnia politum is frequent in our clover fields, the green larva 

 feeding on the clover-louse. A full-grown larva found on the ground 

 March 27 made its puparium the same day, and the fly issued indoors 

 April 8." 



Metcalf has considered a large part of the literature which relates 

 to this species and has given observations made at Raleigh, N. C. In 

 this locality he mentions that the pupae were fastened to the tassels 

 of the corn (p. 30). 



Seasonal Distribution. — This Syrphid was first observed at Jobs- 

 town in a field of metropolitan sweet corn the last week in August when 

 adults and larvae were abundant, which would indicate that the breed- 

 ing season was well advanced at that time. During September, the 

 infestation spread to practically all of the fields. On October 11, the 



1 Loc. cit., Vol. 2, p. 115. 



2 Kept. Ent. Dept. N. J. Agr. College Exp. Sta., 1899, pp. 442-443. 



3 Rept. of Entomologist, Delaware Exp. Sta., pp. 202-205. 



4 Univ. of lU. Agr. Exp. Sta., Bull. 134, p. 148. 



5 Syrphidse of Ohio, Ohio State Univ. BuU., Vol. 17, No. 31, 1913, pp. 16-88. 



