270 PROCEEDINGS OF THE NATIONAL MUSEUM Vou. 113 
MerasurEMENTs: The following measurements were taken from 
3 males and 1 female from Bowmanville, Ill. (CNHM), 1 male and 1 
female from “TIll.”’ (CAS), 2 females from “Ill.’”” (CNHM), 1 female 
from St. Louis, Mo. (CAS), 2 males from Rutland, Sask. (CNC), 
and 2 females from ‘Wis.’”’ (CNC). All measurements are in 
millimeters: 
Males Females 
Mean Extremes Mean Extremes 
Body length 3. 15 3. 0-3. 4 3.28 3.2-3.4 
Elytra length 2. 13 2. 0-2. 4 2.25 2. 1-2.4 
Elytra width at base 1. 40 1. 32-1. 49 1.45 1. 38-1. 55 
Prothorax length 0. 83 0. 79-0. 86 0.90 0. 83-1. 00 
Prothorax width 10 1. 06-1. 15 117 1. 09-1. 22 
Rostrum length Anes 1. 15-1. 22 1.41 1.35-1. 49 
Rostrum length before antennal 0. 39 0. 33-0. 46 0.55 0. 36-0. 73 
insertion 
Funicular segment 2 length 0. 102 0.114 0. 102-0. 119 
Funicular segment 3 length 0.065 0. 051-0.068 0.065 0. 051-0. 068 
Brotoey: Relatively little is known about the biology of this 
species. Schwarz (1884) recorded it as breeding in the flower heads 
of Helenium tenuifolium Nutt.; several specimens from Rutland, 
Sask., Aug. 2 (CNC) are labeled ‘Host: Grindelia.” 
Discussion: This species may be quickly distinguished from the 
other species in this group by the posterolateral dark spots on the 
elytra. 
S. carus (Dietz) is interpreted here as a western population of VS. 
discoideus (LeConte), although there are some superficial differences 
between the two. The type of S. carus (Dietz), a specimen from 
Portola Valley, Calif. (CAS), and a specimen from Elko, Nevada, 
all have several irregular transverse bands of brownish scales on 
their elytra, a regularly shield-shaped elytral macula, and rather 
indistinct posterolateral spots on their elytra. In the eastern popula- 
tion of S. discoideus, there are no transverse bands of brownish 
scales on the elytra, the elytral macula is irregularly shaped, and the 
posterolateral spots are usually distinct. 
Disrripution: Present records indicate that this species may be 
found in the central and northern portions of the interior plains and 
to some extent in the Appalachian highlands. The following speci- 
mens were examined: 
ILLINOIS: ADAMS CO.: Quincy, June (CAS). coox co.: Glenview, April 11 
(CNHM); Willow Springs, July 27 (CNHM). “‘N. Ill.” and ‘‘Til.”” (USNM). 
IowA: DES MOINES Co.: Burlington, Sept. 6 (USNM). picKrinson co.: Lake 
Okoboji, July 28 (USNM). sounson co.: Iowa City, June 10, July 20 (USNM); 
Solon, Aug. (USNM). ‘‘Ia.’? (CNC). 
MANITOBA: Fairbank, Aug. 28 (CNC). 
MIssouRI: sv. LOUIS co.: St. Louis (USNM); St, Louis, July 10 (CAS). 
