G 



It will be seen from this resume of the known larval habits that the 

 habits of the species which we are about to treat are quite abnormal 

 iu its family so far as known. Moreover, in its tribe, Syrphini, it is 

 still more anomalous for the reason that the onl^^ two genera of this 

 tribe of which the larval habits seem to be known, viz, Sijr2)1ins and 

 Sphoerophoria, are carnivorous, feeding upon Plant-lice. 



Mesograpta ijolita^ then, as a plant-feeding species is worthy- of record 

 as of more or less abnormal habit,, as well as on account of its possible 

 effect upon the productive qualities of corn. 



In August, 1885, Mr. E. G. Taggart, of Griggstown, Somerset Gounty, 

 N. J., sent to the Department some pieces of fodder corn taken from 

 a field on his place, and which were covered with small yellowish 

 maggots. His corn had not appeared to suffer from their presence 

 and he was at a loss to know to what to attribute their i)resence. A 

 microscopic examination of the living larvae showed at once that the 

 alimentary canal of each was full of i^artl^^-crushed i)olleu grains, and 

 upon placing the fresh male blossoms of corn in the breeding Jar tlie 

 larvae clustered upon them and were observed feeding upon the pollen 

 grains. 



Subsequent correspondence with Mr. Taggart showed that the mag- 

 gots were noticed during that season for the first time, and when first 

 observed (the third week in August) appeared to be confined to a single 

 patch of fodder corn, occurring so abundantly as to cover the leaves 

 and congregating most in the axils, where the upper leaves join the 

 stalk. This patch of corn was cut August 22, and thirteen days later 

 when it was i)artial}y cured, the worms were observed still living and 

 increased somewhat in size. A patch of fodder corn, distant about 

 one hundred rods from that on which they were first observed, was 

 ])lanted later, and did not blossom until the first week in September. 

 The worms w^ere then found to appear on this patch also, and again the 

 ''stalks became literally covered by them." Strange to say they oc- 

 curred only in these two patches on Mr. Taggart's place j other lields 

 examined by him Avere entirely free from the worms. 



From specimens received from JMr. Taggart August 31 the adult fiies 

 were bred September 7 to 15, the larv;e having become coarctate a day 

 or so after arrival. These fiies were determined by Dr. AVilliston as 

 Say's Meso(/rapfa polita, a species which has a wide range throughout 

 the United Sta^tes east of the ]Mississii)pi, and which is also found in 

 (hiba. It is about 8""" long, and has a wing expansion of It""", and is 

 yellowish in color, marked with brown. 



The damage which will be done by this insect in this way is not likely 

 to be great. Should they increase enornu)usly and spread to othc-r va- 

 rieties of cultivated corn they may reduce the yield considerably by 

 l>reventiug the fertilization of the lemale llowers and the '' make" of the 

 cars. 



