THE STATE ENT0M0L0(3IST. 



121 



THP] PROMETIIEA SILKWORM— .4ffac//.s iCaUosamia] Promdhra, 



Drurv. 



~' /V^ the cocoon itself; these qualities render it les 

 '/^' valuable than that of either the Cecropia o 



(I^fpiilDiitera, Bomhycida'.) 



This is one of our native worms possess- 

 iiig many charac ers which closely ally it to 

 the Cynthia worm. Its cocoon is, like thrtof 

 the two preceding species, elongate and open 

 at one end. It is also double, but tlie outer 

 coat is not loose and rough, but smooth and 

 solid like a jiiece of tough nianilla paper; and 

 there is very little space, and consequently 

 very little floss silk between it and the inner 

 coat. The silk is finer, weaker, less in quan- 

 tity, and much more closely compacted and 

 agglutinated than in the others, and, when 

 coupled with the fact that it is suspended by a 

 rope or cord, as long as, and often longer than, 



less 

 I'opia or 

 Cynthia worms. Indeed, under present con- 

 ditions, the cocoon of Promethea is valueless, 

 as it cannot be reeled, and I doubt whether it 

 could even be carded. 

 The Promethea moth lays her eggs on the twigs of the tree which is to 

 supply the worms with food, in clusters of five or six together. They are 

 of the -size and form of those of cynthia, of a pale cream color, var- 

 iously shaded with a broAvn gummy substance, which is often mixed with 

 the hairs of the mother's abdomen. They hatch in the latitude of St. Louis 

 from the middle to the last of June. 



Larval Ciian-ces.'— The youug, in the first stage, is very much like that of Ci^«//t(«, being yel- 

 low, with six rows of tubercles ; but instead of having two spots to each joint between these tubercles, 

 it has two transverse dorsal black stripes on each joint, the posterior reaching a little further do'vn 

 than the anterior. The tubercles are blunt, thickened at tip, and are white, except on the thoracic 

 and anal joints, where they are tipped with black : they are furnished with long bristles, Avhich are 

 also pale, except on the joints just mentioned. The head is yellow, with two transverse dark bands, the 

 upper one broad and excavated laterally. In the second stage there is no essential change, except 

 that the black tips are confined to the 4 uppermost tubercles on the first, and those on the anal 

 joints; the black stripes are also more conspicuous. In the third stage (Fig. 43, a) the body is paler; 

 the transverse stripes are more conspicuous, the bristles on the tubercles are shorter, having more 

 the appearance of spines, and the two uppermo.it tubercles on joint 2 are often tipped with l)lack. In 

 the fourth stage there is considerable variation, but generally the body is still paler and covered with 

 a whitish pruinescence or powder which recalls the powdery ajjpearance of c^(i/Aia at the same age; 

 the transverse stripes are broader (Fig. 43, c, represents an enlarged side view of one of the joints) and 

 show a tendency to approach between the tubercles; the dorsal rows of tubercles are sulphur-yellow, 

 except on joints 1 and 12, where they are black, and the central yellow tubercle on joint 11 becomes 

 more pronSinenl; the subdorsal row is entirely black, and the stigmatal row is black oil the thoracic 

 joints and yellow on the rest; three black ventral tubercles each side of thoracic joints are now often 

 quite conspicuous; the spines correspond in color to the tubercular stalk; the head (Fig. 43 6) is yel- 

 low, with the lips an 1 triangular piece ;white, and is jn-ettily marked with black, as follows: two 



