312 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



The larva of typical rustica, differs somewhat from that of 

 the island form, as can be seen from the following description 

 of rustica rustica by Rothschild and Jordan : "Larva finely 

 granulated, with seven side-bands, which are white and bor- 

 dered green in front." The larva illustrated by Smyth in Ent. 

 News, XI, 486, 1900, resembles much more another rarer form 

 of larva taken, which is nearly smooth, and may or may not 

 belong to this species, and which is described later. 



The pupa is reddish brown, with a short detached tongue- 

 case applied to the breast by its pear-shaped extremity. The 

 tongue-case is roughened subdorsally by sharp transverse 

 ridges. Length 50 mm. 



Larva and adults of P. rustica calapagensis were observed 

 at Chatham in February, 1906, the latter being rather worn, 

 and the former in several instars, but scarcely mature (Feb- 

 ruary 23, 1906). A few days later, on Charles Island, eggs 

 and adults were secured. The height of the larva season, is 

 March and early April, when they were to be found in numbers, 

 at Iguana and Tagus Coves, Albemarle Island. At the latter 

 cove, they were found up to an altitude of 3000 feet, but were 

 commoner at lower levels, where Cordia lutea, one of the 

 BorraginacecB abounded. This is the most popular of its food 

 plants, while Clerodendron molle (Verbenaceae) appeared to 

 replace it as a food-plant, on Charles and Chatham; and in 

 some localities on Albemarle, the large arboreal Heliotrope, 

 Tournefortia rufo-sericea, was preferred. That the caterpillar 

 is not particular as regards its food-plant, may be further 

 inferred from the fact that it was also found feeding on Eri- 

 geron lancif alius, one of the CompositcB, Croton scouleri var. 

 Macrcsi, and Bastardia viscosa (Malvaceae). The larva of 

 rustica calapagensis was found to be more frequently parasit- 

 ized than those of the other Sphingidco. 



Pupation took place in March and April, especially in the 

 latter month, when pupse could be readily obtained at Tagus 

 Cove, by digging among the roots of Cordia lutea. The adults 

 emerge two or three weeks after pupation, though a small pro- 

 portion seem to remain in the pupal stage until the next rainy 

 season. The moths were plentiful at dusk, at the flowers of 

 Cordia lutea, Clerodendron molle, etc., and were not difficult 



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