THE FOUR-LINED LEAF-BUG : PUPA AND PUPAL CHANGE. 275 



black, aud a short black liue ou their outer side below the kuee. The 

 feet are more slender than the shanks and are three-jointed, the two 

 first joints a little longer than thick, the last joint nearly as long as 

 both the preceding, and black except at its base, with a pair of brown 

 claws at its tip. 



" Varieties, a. The outer black stripe on the thorax wanting. 



"b. The black dot at the end of the outer stripe on the wing-covers 

 wanting. 



" c. The black bands above the knees wholly wanting, or replaced 

 by one or two dots on the outer and inner sides of the hind pair." 



The Pupa. 

 The pupae, as in most of the Hemiptera, are equally active with the 

 perfect insects (imagines), and feed in company with them, yet they 

 are easily to be distinguished. They are much smaller in size. While 

 the latter measure (average of ten examples) 0.27 in. in length, and 

 0.1 in. in width, the former average 0.16 in. long by 0.08 in. broad. 

 They may at Once be recognized by their wing-sheaths in the 2")lace of 

 wings, which are black, with the exception of a pale yellow longitudinal 

 stripe on their outer half, and reach only about one-half the length of 

 the abdomen. The abdomen is black above on all of the eight seg- 

 ments visible, except on their posterior and lateral margins ; beneath 

 it is orange, with a central black streak on the last segment. The legs 

 are pale ; the femora (thighs) are blackish at the base, with three 

 narrow black bands near their tip ; the tibias (shanks) are also black- 

 isii at their base, and under a lens, numerous minute black spines «iay 

 be seen ; the tarsi (feet) are black at the base and tip. 



Transformation. 



The change from the pupa to the perfect insect was made in so short 

 a time, that although more than a hundred examples underwent their 

 transformation in a glass jar upon my table where they wei'e frequently 

 examined, yet in only one instance was the operation detected. It 

 proved so interesting, particularly in the attendant gradual cliange of 

 color, that it was watched, and the following notes thereof taken : — 



When first discovered, the pupal integument had split upon the 

 buck and separated so as to show the larger part of the thorax of the 

 inclosed insect, the basal portion of the wings and the intermediate 

 scutellum ( v). The characteristic and conspicuous black marks per- 

 taining to maturity were entirely absent — the only shades observable 

 being orange, yellow and white ; the thorax was pale yellow, the 

 scutellum light yellow with its lateral angles orange ; the wings were 

 white. In this condition the insect rested for a few minutes, with the 



