194 REPORT OF THE COMMISSIONER OP AGRICULTURE. 



has been copied far aud wide by the agricultural press sufficiently indi- 

 cates the general interest taken in this imi)ortaut insect. The .studies 

 of the past season have resulted in the discovery of several new facts of 

 interest, which we here give. 



Geographical distribution. — The midge has been rei)f>rted from nearly 

 every section of New York State, and Mr. Lintner has collected speci- 

 mens on Mount Equinox, Vermont. It will undoubtedly be found in 

 all the neighboring States. During the past summer clover in the Dis- 

 trict of Columbia aud across the river in Virginia has been sadly dam- 

 aged by this insect, and specimens were collected in the southern part 

 of the State close to the North Carolina border-line, in the latter part of 

 May, by Mr. Howard. 



Food plants. — In addition to destroying the seed of the red clover 

 {TrifoUum praiense) the larviae of G. Icguriienicola iiave been found in 

 considerable numbers in the heads of the common white clover (T. 

 repens) upon the department grounds in Washington. 



The eggs.— 'So observations have heretofoi-e been made upon the 

 eggs of this insect, the last report of this department sim3)ly containing 

 the conjecture that they would i>rove similar to those of the Hessian fly 

 and wheat midge. During the month of September last the midges 

 v/ere observed copulating and the females afterwards laying their eggs. 

 The eggs are so small that it is almost impossible to see them with the 

 naked eye. Their average length is .27™"^ (.01 inch.) They are a 

 long oval in shape, their length being three times their breadth, and 

 one end is slightly larger than the other. The general color is pale yel- 

 low, and an orange streak is more or les>s evident, according to the age 

 of the embryo. The chorion is transparent and polished. 



The female in depositing her eggs simply pushes them down between 

 the hairs which surround the seed capsule of the yet undeveloped 

 florets. They do not appear to be glued to the hairs nor are they 

 inserted into' the skin of the capsule, and I have never seen them pushed 

 into the closed florets. After the larvae hatch, they have to work their 

 way to the seed through the mouth of the flower. The eggs are usually 

 laid singly, but are often found in clusters of from two to five. In one 

 flower-head I have counted over fifty eggs. 



The larvae ; variation in color. — The specimens of the seed maggots 

 received last year from Yates County, New York, were bright orange- 

 red in color, while those found this spring in Washington were nearly 

 white, occasionally with a tinge of pinkish. Specimens received about 

 the middle of the summer from Otsego and Schoharie Counties, New 

 York, were also nearly white in color, while specimens from Yates 

 County had still the strong orange tinge. 



As stated in the report for 1878, the full-grown larvae leave the clover 

 heads and faU to the ground where they form for themselves small 

 cocoons. As they leave the heads of clover, the sight is an interesting 

 one. A head, which one moment is motionless, and at a glance seems 

 to have no animal life about it, becomes, the next, fairly swarming with 

 these maggots. From nearly every closed floret one emerges and wrig- 

 gles violen'tly, until it works its way so far that it falls to the ground. 

 A patch of clover, which vras observed by Mr. Howard, on the morning 

 of May 23 last, seemed entirely alive with the issuing maggots aiid 

 their accompanying parasitic foes. 



The pupa. — No description has as yet been given of the pupa of this 

 insect, probably owing to the difliculty of removing it from its cocoon. 

 The pupa is pale orange in color, with brown eyes. On the front of the 

 head are two short conical tubercles, and behind them two long bristles. 



