40 



MASS. EXPERIMENT STATION BULLETIN 239 



wiien lield r;ither late. When it is let off in April, hatching usually begins 

 about May 15 and continues till about .July 1. 



The Worm. 



During most of their life the worms (Plate Three, figs. 3 and 4a) are green 

 with several white lines along the back and sides and a narrow light yellow 



Green Cranberry Spanworm. 

 Fig. 30. One egg. Greatly enlarged. 



stripe along each side. In their last stage (Plate Three, fig. 4b) the green has 

 a yellow tinge and the whitish lines are obscure except for a pair along each 

 side of the back which often are more marked. They mature from about June 

 10 to about July 22, becoming an inch long. 



The Pupa. 



The worms pupate in the litter under the vines. 'I'he pupa is jiale greenish 

 at tirst but becomes dark brown as the moth develops. It is about a third of 

 an inch Ion"'. This staae lasts about ten davs. 



The Molh. 



The n)oths emerge irregularly from late June till early August, the males 

 tending to appear first. The male (Plate Three, fig. 2) is pale yellowish. Its 

 head bears long pectinate feelers. Its wings expand a little over an inch. 



The female (Plate Three, fig. 1) is sulfur yellow and expands about seven- 

 eighths of an inch. Its wings have noticeable brown spots which vary, but com- 

 monly are arranged as follows: The \ip})er surface of each front wing with 

 three against the front margin, one against the hind margin, one in front of 

 the center, and five to seven small ones along the outer border; the under 

 side of the front wing with one in front of the center, some small ones along 

 the outer border, and a streak toward the outer end and parallel with the 

 outer border; the upper side of each hind wing with a spot in front of the 

 center, another against the hind margin, and several toward and on the outer 

 border; the under side of the hind wing with one near the center and often 

 a series running ])arallel with the outer liorder. All the wings have brown 

 sprinklings on the under side and the outer borders on fresh specimens have 

 brown fringes. The moths brush off many of their scales, often losing their 

 markings and even their yellow color. The feelers on the head are threadlike. 



The males are more active than the females, but they rest much among the 

 vines, flving less than the males of the brown s])an\vorin. They are flushed up 



