§4 NEW YORK STATE MUSEUM 



abundance of moisture. We have kept them aHve in sealed water- 

 iilled cells without food for five weeks. With our present knowl- 

 edge we see no reason why artificial colonies might not be established 

 in the vicinity of a zoological laboratory and maintained with very 

 little or no attention from year to year, if not for a decade or more. 



Description. The parents of these remarkable larvae are 

 small midges belonging to the Dipterous family Itonidae, better 

 known as the Cecidomyiidae or gall midges. The members of this 

 family are all small Diptera with the tibiae unarmed apically, the 

 coxae not produced and the wings usually with but three or four 

 long veins and no cross veins. Extreme forms may have six or 

 seven long veins and one cross vein or, as a result of reduction, the 

 veins may have nearly disappeared. 



The subfamily Heteropezinae, to which Miastor and its allies 

 belong, comprises a number of exceedingly, peculiar forms, some of 

 them most remarkable on account of the great degree of specializa- 

 tion by reduction — physiological as well as morphological. Mem- 

 bers of this subfamily may be separated from the Itonidinae by the 

 absence of circumfili, and from the Lestremiinae by the great reduc- 

 tion in the venation, there being at most, three long veins. The 

 metatarsus may be longer than the following segment, while the 

 number of tarsal segments may be reduced to two. Certain species 

 have quinquearticulate tarsi and the wing membrane thickly clothed 

 with rather broad, striate scales. The production of larvae by 

 larvae or pedogenesis is known to be true of several genera referable 

 to this subfamily, the larvae of which appear to live for the most 

 part in decaying vegetable matter and are therefore likely to be 

 found in searching for jMiastor larvae. The adults of Miastor 

 appear in June, while the one known x^merican species of Oligarces 

 was taken in July. The following table will facilitate the recogni- 

 tion of the genera in this group. 



KEY TO GENERA 



a Metatarsus longer than the second segment 



b Tarsi quadriarticulate ; 3 long veins ; palpi biarticulate T^Iiastor Mein. 

 bb Tarsi triarticulate; 2 long veins; antennal segments cylindric 



Heteropeza Winn. 

 aa Metatarsus shorter than the second segment 

 b Tarsi quinquearticulate 



c Wing membrane finely haired 



d 3d vein extending to the apex of the wing 

 e Palpi quadriarticulate 



/ 5th vein forked Haplusia Karsch 



ff 5th vein simple Johnsonomyia Felt 



