408 



JOURNAL OF ECONOMIC ENTOMOLOGY 



[Vol. 8 



Male. — Length, 1 mm. Antennae a little longer than the body, thickly haired , 

 yellowish; 14' segments, the fifth with stems two and one-half and three times their 

 diameters, respectively; terminal segment produced, the distal enlargement stout, 

 cyhndric, with a length nearly three times its diameter and broadly rounded apically. 

 Palpi; first segment short, sub quadrate, the second with a length three times its 

 diameter, the third a httle longer, shghtly dilated, the fourth one-fourth longer than 

 the third, slender. Thorax and abdomen pale yellowish, the base of the latter some- 

 what tinged with orange. Wings yellowish transparent, costa pale yellowish. 

 Halteres yellowish transparent. Legs yellowish; claws slender, strongly curved, 

 simple, the pulvilli shorter than the claws. Genitalia; dorsal plate short, deeply and 

 narrowly emarginate, the lobes obhquely emarginate; ventral plate long, tapering, 

 slightly, subtruncate; style long, narrowly rounded. Type Cecid. 107f . 



Retinodiplosis Kieff. — The genus Retinodiplosis, erected by Kieffer 

 in 1912 with Cecidomyia resinicDla 0. S. as the type, represents a 

 well-defined group comprising such pitch-inhabiting forms as Ce- 

 cidomyia inopis 0. S., C. resinicoloides Wims. and the closely allied 

 species characterized bleow. 



Members of this genus are mostly dark red or reddish-brown and 

 may be recognized by the short, almost transverse basal stems of the 

 flagellate antennal segments, the rather long, broad, distal enlarge- 

 ment, and the fine, short, many-looped circumfili in connection with 

 the rather heavy genitalia, the two plates being usually deeply bilobed. 

 The larva is easily recognized, in that the posterior extremity is 

 bilobed, the apex of each lobe being fuscous, heavily chitinized, and 

 strongly spined, an adaptation which permits the larva to extend its 

 anal spiracles, located in these lobes, through the surface of the viscous 

 resin it inhabits. 



Retinodiplosis palustris n. sp. — 'The midges described below were 

 reared May 20, 1915, from pitch on twigs of the long-leaved pine 

 collected by Dr. J. J. Davis at Talladega, Alabama, April 9 of the same 

 year. The species is closely related to R. resinicoloides Wlms. from 

 which it may be separated by the longer basal portion of the stem of 

 the flagellate antennal segment and the distinctly greater emargination 

 of the ventral plate. 



Exuvium. — Length, 3 mm., the mesonotum and wing-pads fuscous yellowish, 

 the antennal and leg cases lighter; abdomen semi-transparent. 



Male. — Length, 3.5 mm. Antennae probably nearly as long as the body, sparsel}' 

 haired, reddish brown; 14 segments, the fifth having the stems with a length one and 

 one and one-half times their diameters, respectively; distal enlargement subcjdindi'ic, 

 with a length one-fourth greater than its diameter, the circumfih moderately short, 

 stout and with numerous loops ; terminal segment, distal enlargement produced, with 

 a length about twice the diameter, a constriction near the middle and a somewhat 

 irregular, fingerhke process apically. Palpi; the first segment subquadrate, with 

 a length nearly twice its diameter, the second nearly twice the length of the fu'st, 

 the third a httle longer than the second, and the fourth a httle longer than the third. 

 Mesonotum dark brown, the submedian lines short, silver-haired. Scutellum reddish 



