144 MOSQUITOES OF NOKTH AMERICA 



Male. — Palpi short, slender, about one-sixth as long as proboscis. Antennae 

 similar to those of the female, but the hairs rather longer and more abundant, 

 a small secondary subapieal whorl on each segment. Coloration as in the 

 female. Wing venation and vestiture similar. Abdomen subcylindrical, some- 

 what expanded towards tip, with groups of coarse bristles apically. Legs with 

 the tibiae and tarsi pale bronzy beneath; mid tarsi with apical two-thirds of 

 second and all the succeeding joints silvery white on outer side ; hind tarsi with 

 last two joints white beneath, except at their apices. Mid tarsi with a long and a 

 short claw, those of hind tarsi small and subequal; formula, 0.0-0.0-0.0. 



Length : Body about 3.5 mm. ; wing 3 nun. 



Genitalia (plate 2, fig. 7) : Side-pieces over twice as long as viride, the tips 

 conically tapered; three hairs in a row at middle of side-piece; clasp-filament 

 with a rather stout grooved stem, tip greatly expanded and distorted, middle 

 lobe broad, with a row of fine setse along its margin, apex of shaft bearing a 

 stout tooth, inner lobe small, the outer one inflated in bladder form, veined 

 from its base, with a capitate tip. Harpes rounded quadrate, tips bent down- 

 ward and produced into large sharp spine, at the angle a semi-articulated crest, 

 thick, with elliptical tip, and fringed on one side with long coarse lamellae. 

 Harpagones small, slender, with the unci forming a rounded triangular basal 

 plate. Basal appendages represented by a row of six or seven spines on each 

 side. Penultimate segment roundedly angled at sides, the angles prominent 

 and densely setose; posterior margin of the venter also coarsely setose on 

 each side. 



Larva, Stage IV (plate 93, fig. 395). — Head rounded, roundedly truncate 

 in front, with a large notch for the insertion of the antennae, no lateral 

 angles ; antenna small, stout, smooth ; lower dorsal head-hairs and ante-antennal 

 hairs single. Lateral abdominal hairs in twos or threes on first two segments, 

 single on the follovring ones. Air-tube long, gradually and slightly tapered, 

 about seven times as long as wide, the terminal hooks rather long; two single 

 hairs on dorsal aspect near the middle, one on ventral aspect towards the base, 

 and another towards the apex; a black ring at base of tube. Lateral comb of 

 eighth segment of five large pointed teeth situated upon a large plate, which is 

 angled in the middle behind and bears a hair at upper and lower margins. Anal 

 segment longer than wide, with a large dorsal plate, spined on posterior margin 

 and thickened and black on anterior and subventral margins; dorsal tuft of 

 two long hairs on each side; lateral hairs single, long, arising from middle of 

 side of plate ; subventral tufts of three rather long hairs. Anal gills four, nearly 

 equal, the upper pair a little shortened, the lower ones scarcely longer than the 

 anal segment, the tips rounded. 



The larvae live in water in bamboo-joints and similar locations. Mr. Busck 

 bred the species from a larva in bamboo, associated with Sdbethinus undosris. 

 Mr. Jennings obtained the larvae in bamboo-traps. 



Panama. 



Tabemilla, Canal Zone, May 10, 1906, larva3 in bamboo-joints (A. Busck) : 

 May 23, 1908 (A. H. Jennings). 



This species, when first submitted to study, was supposed to be Wyeomyia 

 chalcocephala, but further study revealed differences. Its description under two 

 separate names was due to an error of observation of the specimen which served 

 as the type of symmachus. The prothoracic lobes are in fact not tipped with 

 white as described, the error having been caused by the shining appearance of 

 the scales. 



