300 



NEW YORK STATE MUSELM 



Introduction. This insect was doubtless introduced with imported 

 nurser)- slock. .Some infested willows were probably used to bind imjjorted 

 trees into bundles, and this is borne out by the fact that thc! locality where 

 the flies were found is in close pro.\imity to a place where an importer 

 had been in th(! habit of unpackin,<r stock. 



Life history. .\(hilts were' bred from InfestL'd galls collcctetl earl)- in 

 the season, Irom .Ma)- 22 and onward. Other specimens received directly 

 from the held, June 3 were disclosing ilic:., showing that in nature the adult 

 issues at this time. The pupa, like those of 

 many Cecidomyiids, wriggles ])artl\- out of the 

 gall before disclosing the adult, and so many 

 ma\- emerge Irom a gall that it presents a some- 

 what peculiar appearance after the flies have 

 escaped because of the numerous white, project- 

 ing pupal cases. 



ihe reddish orange eggs were deposited by 

 (■apli\e llies on the leaves in irregular clusters 



FiK. 58 Two antennaiscgnientsof European orgroups of three to si.\ oruiorc. Tile dura- 

 willow gall midge; rtmalc; /. -female; 



both much enlarged tlon of tile cgg Stage aud of the larval existence 



was not determined. It seems probable that there is but one annual 

 geni-ration. 



Description. The sniall black or dark brown tlies are about ^i inch in 

 length. The eyes are black, finely granulated, cmarginate anteriorly, 

 conlluenl in tlu; male and iiearl)- so in the female. IIk; male antennae are 

 17 jointed and an^ about the length of the insect and the female antennae 

 are about half lier length. The interesting structures occurring on the 

 segments of the male and female antennae are shown in figure 58. The 

 thora.-«v is ornamented with two converging rows of silver)- liairs, and a short 

 row of smaller ones occurs on each humeral angle. Ihe metathora.x is 

 ti|jped with a traiis\-erse row of the same \-estilurt\ The xenalion of the 

 wings, which are sparsely covered and well fringed with dark hairs, is rejire- 

 sented in figure 59. The balancers or halteres are slender and lippetl with 



