354 FOREST ENTOMOLOGY. 



Family CECIDOMYIDiE. 



"Ocelli often absent. Thorax with no transverse suture. Antennoe 

 long, composed of many segments (10-36). Wings with only few 

 nervures. Coxae not elongated, femora not thickened, no spurs on 

 tibiae. Delicate midges or gall-flies whose larvae are provided with 

 an anchor process beneath the head end. 



Genus Cecidomyia. 



"Antennae long and moniliform or cylindrical ; generally verticillate, 

 13-3G joints. Wings hairy, and -have densely pubescent margins. 

 Three or four longitudinal veins. There are two types of wings. In 

 the first type the third vein is forked, thus representing the third 

 and fourth veins, which have united for most of their length. In 

 some rare cases this fork may become obliterated. In the second type 

 of wing the four veins are separate and simple. We must note in 

 these insects a curious longitudinal fold between the second and 

 third longitudinal veins, present in most Cecidomyidae." 



The following are the more important as regards arboreal insects 



— viz. : 



^ ^ ( Dasyneura, Ed. 



" Cecidomyia, Lw. = - _., -,^ ^ 



I Rhabdophaga, Westw. 



" Same number of joints in the ^ antennae as in the $ . The joints 

 may be pedicelled or sessile. The second longitudinal vein reaches 

 the margin of the wing before its tip. 



^ ^ C Phytophaga, Ed. 



" DiPLOSis, Lw. = - -r, T. 1 



( Bremia, Ed. 



"The antenna3 of ^ = 26 to 27 joints ; that of the $ = 14 to 15. 

 The joints are pedicelled. The second longitudinal vein reaches the 

 margin beyond the tip. The joints of the antennae, of the ^ double 

 the number of those of $ . 



" Hormomyia, Lw. = Angelinia, Ed. 

 " This sub-genus is distinguished by the gibbose thorax, which is 

 often drawn over the head. The second longitudinal vein ends as 

 in the preceding sub-genus. Wings without lustre. 



