404 



Wirth and Stone: Diptera 



4. Stem vein with pale yellow hairs; Del None and Modoc 



counties to San Luis Obispo County 



exigens Dyar and Shannon 1927 



Plumas, El Dorado and Mariposa counties 



hirtipes (Fries) 1824 



Nevada County travisi Stone 1952 



— Stem vein with dark hairs (Trinity, Shasta, and Sierra 

 counties) dicum Dyar and Shannon 1927 



Males 



1. Integument orange fulvum (Coquillett) 



— . Integument dark brown to black 2 



2. Antenna with 1 1 segments 3 



— Antenna with 9 segments (presumably) 



novum Dyar and Shannon 



3. Hind femora, at least, yellow 



onychodactylum Dyar and Shannon 



travisi Stone 



— Hind femora brown or blackish. 4 



4. Ventral plate with a compressed median keel; parameres 

 large, flattened, sclerotized plates, bluntly rounded 

 apically exigens Dyar and Shannon 



— Ventral plate centrally with a down-curving lip, but 

 not forming a compressed median keel; parameres much 

 smaller, somewhat tapering distally 



dicum Dyar and Shannon 



hirtipes (Fries) 



Pupae 



1. Respiratory organ consisting of 2 stout, divergent, 

 distinctly ringed tubes, on a short petiole, from which 

 slender filaments arise # . . . 



onychodactylum Dyar and Shannon 



— Respiratory organ not so formed 2 



2. Respiratory filaments 16 3 



— Respiratory filaments more than 40 4 



3. Filaments of respiratory organ closely clumped; dorsum 

 of thorax rugose travisi Stone 



— Filaments of respiratory organ with the main trunks 

 divergent; dorsum of thorax not rugose 



fulvum (Coquillett) 



hirtipes (Fries) 



4. Thorax strongly rugose dicum Dyar and Shannon 



— Thorax not rugose exigens Dyar and Shannon 



The pupa of Prosimulium novum is not known. 



Genus Cnephia Enderlein 



Species of this genus have a biology rather similar to 

 those of Prosimulium, there apparently being only 

 one emergence in the year in the early summer. Two 

 of the species will sometimes be found annoying to 

 man, although osborni was collected from a grouse. 



sense organ 0.3 length of segment; Plumas and Sierra 



counties stewarti Coleman 1953 



Wing length from humeral cross vein less than 3.5 mm.; 

 basal tooth of claw not more than half as long as claw; 



palpal sense organ 0.5 length of segment 



osborni (Stains and Knowlton) 1943 



Males, 



1. Radial sector with a short but distinct anterior branch 



-. stewarti 



Coleman (presumably also osborni Stains and Knowlton) 



— Radial sector unbranched 2 



2. Dististyle with 2 rather blunt terminal teeth; calcipala 

 large, rounded apically mutata (Malloch) 



— Dististyle with only a single terminal tooth; calcipala 

 smaller, the tip more acute ..minus (Dyar and Shannon) 



Pupae 



Pupae of only two of the California species are 

 known. The pupa of mutata has usually twelve respir- 

 atory filaments arising irregularly from two main 

 trunks, and terminal hooks are present on the abdomen. 

 That of stewarti has six swollen respiratory filaments 

 in three pairs, one pair pointing forward, the other 

 two somewhat petiolate and pointing backward. 



Genus Simulium Latreille 





Of the nineteen species here included in the genus 

 from California, four (aureum, canonicolum, latipes, 

 and pugetense) belong in the subgenus Eusimulium; 

 two (argus and vittatum) to the subgenus Neo simulium; 

 four (bivittatum, griseum, trivittatum, and venator) to 

 the subgenus Lanea; one (virgatum) to the subgenus 

 Dyarella; one (canadense) to the subgenus Hearlea; 

 and the remaining seven belong to the typical sub- 

 genus. There are at least three undescribed species 

 from California not included in the following keys. 

 Since they are not all known in both sexes and the 

 pupa, where the unknown sex or pupa will run in the 

 following keys is not known, so caution should be 

 used when attempting to determine species from these 

 keys. 



There is a rather wide variety of habitats and habits 

 within the genus, and much remains to be learned 

 about seasonal and geographical distribution and 

 feeding habits. Species of the subgenus Lanea rather 

 typically inhabit desert regions. 



Keys to the California Species of Cnephia 

 Females 



1. Tarsal claws with a distinct tooth or strong basal 

 projection 2 



— Tarsal claws simple; Plumas, Placer, and El Dorado 

 counties mutata (Malloch) 19 14 



2. Radial sector with a short but distinct anterior branch 



3 



— Radial sector unbranched; Plumas, Placer, and El 

 Dorado counties minus (Dyar and Shannon) 1927 



3. Wing length from humeral cross vein 4 mm.; basal toot! 

 of claw long, more than 1/2 length of claw; palpa 



Keys to California Species of Simulium 

 Females 



1. Vein R with hair dorsally « 



— Vein R without hair dorsally 4 



2. Postscutellum with a patch of yellow appressed scales; 

 scape and pedicel of antenna pale brown; Siskiyou and 

 Iflaaen counties: Contra Costa and Mono counties to 

 Los Angeles and San BernarHino counties 



- aureum Fries 1824 



— Postscutellum without scales; antenna entirely dark 

 3 



3. Stem vein with dark hair which may appear coppery in 

 reflected light; Plumas County. ... latipes Meigen 1804 



