NO. 3665 CADDISFLIES—-FLINT an 
Since the cases show good generic differences—except between 
Leucotrichia and Zumatrichia, and between Hydroptila and Ochro- 
trichia—they are more useful in the placement of the pupal stage 
than the pupae themselves, which are only slightly different. In 
the majority of the genera it is impossible to key the immature 
stages to species. The larvae and pupae of Bredinia are unknown. 
Key to Genera 
LARVAE AND CASES 
1. Larvae with abdominal terga bearing sclerites; case flattened and tightly 
appressed to substrate, never movable. . ... ee 
Larvae with a sclerite on ninth tergum only; case eros enemed! but 
carried by larva and attached at pupation . . . es BOS | 
2. Abdominal segments 3-6 greatly cscs case Oe domeal with openings 
ae DOUM Ends! 2 jo. 6 ..« yaa 
No abdominal segment salieaned case Pacasly Snaviks, flat, ain ein 
openings .... Sees ss ee 6 ey Alisotrichia 
3. Ninth tergum with ationt, euiarged sta ees, es a) > IMA triChia 
Ninth tergum with only normal hairlike setae. . . . . . . . Leucotrichia 
4. Mid- and hindlegs about 3 times as long as forelegs; case silken, anterior end 
cylindrical, becoming enlarged and compressed posteriorly . . . Oxyethira 
All legs of about same length; case generally with some sand or organic 
matter, differently shaped .... . : A ae nei OO 
5. Anal prolegs projecting freely from abdomen; case sabular made of 
BCA Sr es ... . . Neotrichia 
Anal prolegs fused to sil of apdercene case ome Dae, Geren th ie or 
6. Metanotum with anterolateral angle enlarged. . . . . . . . Ochrotrichia 
Metanotum with anterolateral angle not enlarged. . . . . . . Hydroptila 
ADULTS 
PEOLCCUIEDTCSON Gi.” cauc EAMEy dee ct” Seti vote WEG Os )ae) ad Saucy a eee ener ee 
Ocelliabsent ..... . .. . . Hydroptila 
2. Mesoscutellum with a GRATES autre een aera angles! (iy 2%... 3 
iNMesoscutellumeentire tr is stills, PNT Aa Sod. Oe ed ao 
S-eeloretibia with an.apicalspur .).)elgler a ble 4% wot me bh ue are AA 
Foretibia without an apical spur... . Se Peo ar et a An Gee) 
4. Males with basal antennal segment aalaeeedh covering face, with 2 
Ocelli 2. 3 ss ... . . Zumatrichia 
Basal antennal peemieas enodiaed ae 3 econ et As Macao sseeee eee ey 1. 
5. Forewing fuscus, with linear, bright green marks. . .. . . Leucotrichia 
Forewing fuscus, sometines with silvery-gray blotches 
Ochrotrichia (Metrichia) 
Game vacdiibias with a@preapical spurs. lye. sods eos da Spacer mh ence yerrd 
Midtibia without a preapical spur ... . ay Pe ec eey ms 
7. Male genitalia not greatly modified, Snepers inte Gna. easily recognizable 
OS FOG Ss a6 6 6 . . . . . Ochrotrichia (O.) 
Male genitalia gr andy po cined dagen suell and often difficult to homolo- 
IZ ed Te cate el ce ah ae el cere eh aeta Ode 32? Alisotrichia 
313-152—68——3 
