o. R_{2+3} present therefore cells R_1 and R_3 both present, or if not, then the branches of the radius more or less coalescent, obliterating the cells.
p. At least the tip of the wing with erect setulae; tip of R_{4+5} scarcely attaining the middle of the wing, empodium rather indistinct, not reaching the middle of the claws, the claws not toothed, equal, with long basal bristle; legs without stout setae. Widely distributed. CULICOIDES Latr.
HaeMATOMYIDIUM and OECACTA are probable synonyms of this.
pp. Wings bare, if rarely with hair, then the radius reaches beyond two-thirds the length of the wing, or the femur or fifth tarsal segment with stout black spines.
q. Media unbranched. Europe.
_Brachypogon_ Kieff
qq. Media branched.
r. Hind femur much swollen and spined.
America and Europe. _Serromyia_ Meg.
rr. Hind femur not distinctly swollen.
s. Cell R_1 not longer than high; fork of the media distad of the crossvein; wing with microscopic setulae _Stilobezzia_ Kieff
ss. Cell R_1 elongate.
t. Femora unarmed. Widely distributed. (= Sphaeromias Kieff. 1913 not Curtis?).
JOHANNSENIELLA Will.
tt. Femora, at least in part, with strong black spines. Widely distributed. _Palpomyia_ Megerle
oo. R_{2+3} coalescent with R_{4+5} hence cell R_3 is obliterated.
p. In the female the lower branch of the media with an elbow near its base projecting proximad, the petiole of the media coalescent with the basal section of the radius, wing long and narrow, radial sector ending near the tip of the wing; venation of the male as in _Bezzia_; front concave. United States. _Stenoxenus_ Coq.
pp. Venation otherwise, front not concave.
q. Subcosta and R_1 more or less coalescent with the costa; wing pointed at the apex, much longer than the body; antennae fourteen segmented, not plumose. India.
_Haasiella_ Kieff.
qq. Subcosta and radius distinct from the costa.
r. Abdomen petiolate. _Dibezzia_ Kieff.
rr. Abdomen not petiolate.
s. Head semi-globose; hind tarsi unusually elongate in the female; antennae of the male not plumose. Europe. _Macropeza_ Meigen.
ss. Head not globose, more or less flattened in front; antennae of the male plumose. Widely distributed. _Bezzia_ Kieff.
t. Fore femora, at least, armed with stout spines below.
Subgenus _Bezzia_ Kieff.
tt. Femora unarmed. Subgenus _Probezzia_ Kieff.
ii. Media of the wing simple, and otherwise not as in "i". To this group belong numerous Chironomid genera, none of which are known to be noxious to man.
ff. The costal vein apparently is continued around the hind margin of the wing; radius with at least four branches.
g. Wing ovate pointed, with numerous veins; crossveins, if evident, before the basal third of the wing; veins very hairy; very small moth-like flies. PSYCHODIDae
h. With elongate biting proboscis; the petiole of the anterior forked cell of the wing (R_2) arises at or beyond the middle of the wing (fig. 163d). PHLEBOTOMUS Rdi.
[Ill.u.s.tration: 163. Wings of Diptera. (_a_) Anopheles; (_b_) Prosimulium; (_c_) Johannseniella; (_d_) Phlebotomus (After Doerr and Russ); (_e_) Tersesthes (after Townsend); (_f_) Taba.n.u.s; (_g_) Symphoromyia; (_h_) Aphiochaeta; (_i_) Eristalis; (_j_) Gastrophilus; (_k_) Fannia; (_l_) Musca.]
hh. With shorter proboscis; the petiole of the anterior forked cell arises near the base of the wing.
_Psychoda_, _Pericoma_, etc.
gg. The r-m crossvein placed at or beyond the center of the wing; wings not folded roof-like over the abdomen.
h. Proboscis short, not adapted for piercing; wings bare (DIXIDae); or wings scaled (CULICIDae, Subf.
CORETHRINae).
hh. Proboscis elongate, adapted for piercing; wings scaled, fringed on the hind margin; antennae of the male bushy plumose. Mosquitoes. CULICIDae (exclusive of CORETHRINae)
i. Metanotum without setae.
j. Proboscis strongly decurved; body with broad, appressed, metalescent scales; cell R_2 less than half as long as its petiole; claws of female simple, some of the claws of the male toothed.
Several large southern species believed to feed only on nectar of flowers. _Megarhinus_ R. D.
jj. Proboscis straight or nearly so, or otherwise different.
k. Scutellum evenly rounded, not lobed; claws simple in both s.e.xes. ANOPHELES Meig.
l. Abdomen with cl.u.s.ters of broad outstanding scales along the sides; outstanding scales on the veins of the wing rather narrow, lanceolate; upper side of the thorax and scutellum bearing many appressed lanceolate scales. Florida and southward (CELLIA).
m. Hind feet from the middle of the second segment largely or wholly snow white.
n. With a black band at the base of the last segment of each hind foot. A.
ALBIMa.n.u.s*[H] and TARSIMACULATA*
nn. Without such a band A. ARGYRITARSIS*
mm. Hind feet black, mottled with whitish and with bands of the same color at the sutures of the segments. W. I. A. MACULIPES
ll. Abdomen without such a cl.u.s.ter of scales; outstanding scales of the wing veins rather narrow, lanceolate; tarsi wholly black.
m. Deep black, thorax obscurely lined with violaceous, especially posteriorly; head, abdomen and legs black; no markings on the pleura; abdomen without trace of lighter bindings; wing scales outstanding, uniform, not forming spots, though little thicker at the usual points indicating the spottings.
Florida. A. ATROPUS
mm. Otherwise marked when the wings are unspotted.
n. Wings unspotted.