304 PROCEEDINGS OF THE NATIONAL MUSEUM Vou. 113 
Elytra black, intervals covered with imbricate, elliptical scales, 
mostly white in humeral regions, light or medium brown with a 
scattering of white posterior to humeral regions. Underside of thorax 
and abdomen black, covered with ovate, white scales having a violet 
to bluish iridescence. Femora reddish, slightly clavate, covered with 
elongate and ovate, pale brown to white scales. Tibiae black, 
covered with scales similar to those of femora. 'Tarsi piceous; third 
segment distinctly broader than first two; fourth segment extending 
well beyond third; claws connate near their bases, distinctly divergent. 
Median lobe of male genitalia slightly broadened near apex; internal 
sac exceeding median lobe, covered with fine spines (fig. 84). Arms 
of spiculum ventrale of female genitalia slightly elbowed; anterior end 
of stem not expanded (fig. 134). 
Measurements: The following measurements were taken from 5 
males and 5 females from Williams, Ariz. (USNM) and 5 males and 
5 females from Inyo Mountains, Calif. (USNM). All measurements 
are in millimeters: 
Males Females 
Mean Extremes Mean Extremes 
Body length 2. 19 1. 98-2. 40 2.17 1. 72-2. 66 
Elytra length 1. 60 140-179 1.56 1. 25-1. 82 
Elytra width at base 0. 86 0. 73-0. 92 0.83 0. 69-1. 00 
Prothorax length 0. 53 0. 46-0. 56 0.56 0. 46-0. 59 
Prothorax width 0. 56 0. 49-0. 63 0.57 0. 438-0. 66 
Rostrum length 0. 82 0. 76-0. 89 0.89 0. 76-1. 09 
Rostrum length before antennal 0. 27 0. 20-0. 33 0.39 0. 33-0. 46 
insertion. 
Funicular segment 2 length 0.054 0.051-0.068 0.058 0. 051-0. 068 
Funicular segment 3 length 0.037 0. 034-0.051 0.039 0. 034-0. 051 
Brotocy: The host-plant records which follow were taken from 
the material examined: “Gutierrezia lucida,’ Logan, Utah, June 15 
(USNM); “‘Pluchea sericea,” Leeds, Utah, May 20 (USNM); “Chryso- 
thamnus speciosus,”’ Leeds, Utah, June 15 (USNM); ‘“Aplopappus”’ 
(now Haplopappus), Mesa, Arizona, Feb. 24 (USNM); ‘on Prosopus 
juliflora,”’ Death Valley, Calif., April, Panamint Valley, Calif., April 
(USNM); ‘‘Covillea tridentata,” Glendale, Nev., June 7 (USNM); “on 
Prunus blossoms,” Oak Creek, near Flagstaff, Ariz., May 16 (USNM); 
“Pinus edulus,’ Rhincon Mountains, Ariz. (USNM); “coll. on Pinus 
monophyllum,’’ Argus Mountains, Calif., May (USNM). 
DisTRIBUTION: Present records indicate that S. imbricatus is widely 
distributed in the basin and range province, and has been recorded 
from the Gulf coastal plain and central lowlands in Texas, and the 
Sierra Nevada and coast range sections of the Pacific mountain 
system. The following specimens were examined: 
ARIZONA: COCHISE CO.: Chiricahua Mountains, July (CU); Huachuca Moun- 
tains, (AMNH). coconrno co.: Bright Angel, May 10-July 12 (USNM); Grand 
