Fig. 7^6. Graptocorixa californica Hungerford, male, Moke- 

 lumne Hill, Calaveras County, California, May 29, 1931 (R. L. 

 Usinger). 



193 



Usinger: Hemiptera 



long as tarsus; face with a dense mat of hairs; 3 I 



of long bristles at base of front femur > rnica 



Hung.) Graptocorixa 



— Scent gland openings larger, the middle pair lesa than 5 

 times as far apart as diameter of a single opening. 

 (Middle claws subequal or longer than tarsus; face with 

 scattered hairs but not with a dense mat of hairs; front 

 femora without 3 tufts of long bristles near base) ... 2 



2. Mesonotum entire 1) covered with long shaggy hair ; 

 middle claws subequal in length to tarsus (laevig 

 Uhl.) Ilesperocorixa 



— Mesonotum bare on either side of middle posteriorly; 

 middle claws longer than tarsus 3 



3. Metanotum at middle, and abdomen clothed with short, 

 sparse, bristles backward directed (inscripta Uhl. 

 decolor Uhl.) Corisella 



— Metanotum at middle and abdominal tergites bare ... 4 



4. Abdomen with 6 longitudinal stripes above (mckinstryi 

 Hung.) Sigara 



— Abdomen without longitudinal stripes 5 



5. Scent gland openings large, the space between middle 

 pair about twice the diameter of a single opening; 

 middle of mesonotum bare except at anterior third and 

 narrowly along a median-longitudinal carina (reticulata 

 Guer.) Trichocorixa 



— Scent gland openings small, the middle pair about 5 

 times as far apart as diameter of a single opening; 

 middle of mesonotum broadly pubescent, the lateral 

 bare areas confined to hind margin near inner angles of 

 hemelytral pads (wileyae Hung.) Cenocorixa 



Key to California Species of Graptocorixa 



1. Prothoracic lateral lobe elongate; small, length less 

 than 7 mm. (fig. 7:9a;); Oregon, Nevada, Arizona .... 

 serrulata (Uhler) 1879 



— Prothoracic lateral lobe quadrate, if longer than broad, 

 then of uniform width on species .vath a white spot on 



usually with a dense mat of hairs Graptocorixa 



— Front femora without prominent tufts or a row of bristles 

 on inner margin; face sometimes with sparse hairs but 

 not with a dense mat of hairs 2 



2. Apices of clavi not exceeding a line drawn through 

 costal margins of hemelytra at nodal furrows (fig. 7:7) 



Trichocorixa 



— Apices of clavi exceeding a line drawn through costal 

 margins at nodal furrows 3 



3. Base of clavus with brown bands broken or effaced 

 (fig. 7:56) Corisella 



— Base of clavus without broken or effaced brown bands 



4 



4. Lateral lobes of prothorax trapezoidal, nearly as broad 

 as long; size large, 9-1 1 mm Hesperocorixa 



— Lateral lobes of prothorax distinctly narrower than 

 long; size smaller, less than 8 mm 5 



5. Size small, less than 6.8 mm Sigara 



— Size larger, 6.8 mm. or more 6 



6. Corium rugose but not strongly rastrate; apex of hind 

 tibia and usually also base of first tarsal segment 

 infuscated in vulnerata but not in audeni . . . Callicorixa 



— Corium strongly rastrate; hind tibia and tarsus not 

 infuscated as above Cenocorixa 



Preliminary Key to Genera of California Corixidae 



Based on Fifth Instar Nymphs 



(Mesonotal pads reaching to middle of 

 third abdominal segment) 



1. Scent gland openings very small and widely separated, 

 the middle pair separated by about 10 times the diameter 

 of 1 opening. (Middle claws less than two-thirds as 



Fig. 7:7. Trichocorixa reticulata (Guerin>Menevill«), Oohu, 

 T. H., 1936 (R. L. Usinger). 



