LIFE HISTORY OF THE SQUASH-VINE BORER. 37 



The half-grown larva is described by Dr. Scudder in the article 

 quoted, and this description need not be repeated in detail. The head 

 is jet black and the dorsal surface of the first thoracic segment is nearly 

 black, in both of which respects — as well as in the black anal process, 

 which sometimes ends in a well-defined hook — it differs from the full- 

 grown larva. Length, 13 mm ; width, 2.5 mm . 



A dorsal view of the half-grown larva is presented at e, fig. 7, /show- 

 ing the head and thoracic segments in profile. 



The full-grown larva, figured in profile within an opened squash stem 

 at d, fig. 8, is also fully described in the paper quoted. The head, it 

 will be noted (fig. 7, </), is ornamented with a median white space, being 

 usually dark brown at the sides, and the first thoracic segment is 

 marked dorsally by two curved oblique brown bauds which converge 

 posteriorly. The full length is 25 mm ; width a little more than 6 mm . 



THE COCOON AND CHRYSALIS. 



After attaining maturity the larvse desert the stems and enter the 

 earth, burying themselves to the depth of one or two inches, and form 

 their cocoons in which they transform to pupae. 



In its chrysalis case or cocoon the larva contracts to about 15 mm , the 

 case itself being a little shorter than the larva before contraction, 

 averaging about 22 mm in length by 7 nim or 8 n,m in width. The cocoon, 

 shown at /, fig. 8, is composed of silk and is stout of texture, though 

 rather thin when divested of the outer coat of grains of sand or earth 

 which adhere to it by means of some gummy secretion of the larva. 

 When thus treated it is found to be nearly black in color, both within 

 and without. 



The pupa or chrysalis, shown in profile at e of figure 8, measures about 

 five-eighths of an inch in length (16 mm ). It is shining mahogany brown 

 in color and its head is ornamented in front just above and between the 

 eyes with a horn-like process. By means of this the pupa cuts its way 

 out of one end of its cocoon, and by the aid of the abdominal hook-like 

 spines forces itself to the surface of the earth before transforming to 

 imago. 



THE MOTH BRIEFLY DESCRIBED. 



As a complement to the illustrations and the descriptions of the life 

 stages of this insect the mature moth may be briefly described. 

 . The male moth is illustrated at a of figure 8. It is a most beautiful 

 creature, a member of the family Sesiidre, otherwise known as clear- 

 winged moths. Its fore-wings are opaque, lustrous, olive brown in 

 color, with metallic green reflections, and the expanse is from less than 

 an inch to nearly an inch and a half. The hind-wings, from which 

 this family of moths derives its vernacular name, are clear and trans- 

 parent and veined as shown in the figure. The abdomen is conspicu- 

 ously marked with orange or red and black or bronze, and the hind legs 



