154 UNITED STATES NATIONAL MUSEUM BULLETIN 2 76 



ular black areas both anteriorly and posteriorly, with the posterior one 

 often split longitudinally by yellow; this combination of the vertical 

 black bar and the anterior and posterior black areas forms the "torso" 

 mark, or the "tailed-torso" mark if the black is more extensive on the 

 lower, posterior part. Subdorsal area basically yellow or yellow- 

 orange, but marked with irregular longitudinal black areas which 

 may obscure much of the yellow in some specimens and some popula- 

 tions (fig. 372). Anterior and posterior subdorsal spots blue, varia- 

 ble in size, but usually not large enough to obscure the anterior and 

 posterior "arms" of the torso or tailed-torso mark. Subdorsal line 

 yellow to yellow-orange, irregular, and speckled with black. Supraspi- 

 racular and subspiracular areas usually varying combinations of 

 mixed yellow and black, sometimes with bluish or grayish mixed in, 

 but usually not predominandy blue or gray. Ventral area motded 

 gray-white and black, with a median black area on each segment 

 that is most prominent on light specimens. Primary and secondary 

 dorsal setae orange; sometimes a few of the thoracic primary setae 

 may be blackish. Primary and secondary lateral setae also orange 

 or yellowish. Specimens of c. pluviale with white setae have never been 

 seen except near the zones of intergradation with other populations. 

 Both dorsal and lateral secondary setae rather sparse, short, and 

 not noticeably tufted. 



LARVAL DIAGNOSIS. — The subspecies is best recognized by dif- 

 ferences in the larval color pattern, but intergradation with adjoining 

 populations is complete and gradual west of the Great Plains. In general, 

 c. pluviale larvae are predominantly black and yellow or yellow-orange, 

 with the anterior and posterior subdorsal blue spots small to moderate 

 in size and not conspicuous. The supraspiracular and subspiracular 

 areas are usually mixed black and orange with little blue or blue-gray, 

 and all setae are some shade of yellow-orange. Adjoining populations 

 generally have conspicuously larger anterior and posterior subdorsal 

 blue spots which may be confluent, the supraspiracular and subspirac- 

 ular areas are usually more bluish or grayish, and the lateral setae may 

 be white. Many populations in the area of intergradation will be almost 

 exactly intermediate in the color combinations of blue, orange, and 

 black, but they should not be regarded as c. pluviale unless the black and 

 yellow-orange dominate. 



EGG MASSES. — Laid as a basically flat, clasping mass (fig. 105) and 

 covered with brown to dark brown spumaline that is sometimes more 

 compact in the Pacific populations than in the more eastern ones. 



TENTS AND COCOONS.— Similar to those of M. californicum 

 californicum (page 141). 



