THE CONTROL OF THE SQUASH YINE BORER IN MASSACHUSETTS. 



By HARLAN N. WORTHLEY. 



Distribution and Importance. 



The squash vine borer^ is a native of the New World, and apparently is of tropical 

 origin. It has spread northward over that portion of the United States east of the 

 Rock}' Mountains, and into Southern Canada. It is found as far south as Argentina. 



In many localities the squash vine borer is the most serious enemy of ^^^nter 

 squashes. Pumpkins and summer squashes are also affected, and more rarely 

 melons and cucumbers. 



Description. 



Egg. — The egg of the squash vine borer is shown in Plate I, figure 1 and Plate 

 II, figure 2. It is about one-twenty-fifth of an inch in length, and is of a dark 

 reddish brown color. As may be seen in Figure 1, the eggs are not laid in clusters, 

 as in the case of squash bug eggs, but singly. Magnification, as in Plate II, figure 

 2, shows the chorion to be finely reticulated into tiny hexagonal figures. 



Larva.- — The larva, or "borer" (Plate I, figure 1 & Plate II, figure 3) as it is 

 commonly called, is a fleshy, white, nearly hairless caterpillar with a black head 

 and a dark brown to black thoracic shield. When full grown it measures about an 

 inch in length. Newly-hatched larvae, which are commonly not detected in the 

 field, are about one-sixteenth of an inch long, sparsely covered mth hairs, and 

 with a broad black head, from which the white body tapers away to the anal ex- 

 tremity. In appearance the borer is quite distinct from the larva of the striped 

 cucumber beetle, with which, however, it is often confused. The latter is but three- 

 tenths of an inch long and is very slender, with the head and anal plate dark brown. 



Pupa. — The pupa (Plate I, figure 1) is contained in an earth-covered cocoon 

 of very tough, black sHk about three-fourths of an inch long. The pupa itself is 

 about five-eighths of an inch long, and is of a dark shining brown color. The head 

 bears a horn-like process between the eyes, and the abdomen bears circles of hook- 

 like spines. 



Adult. — The adult moth (Plate I, figure 1) is five-eighths of an inch or more in 

 length, with a wing spread of an inch to an inch and a half. It is strikingly beautiful, 

 ■with long narrow olive green fore -wings, bearing a fringe of blackish hairs at the 

 tips. The hind wings are transparent, bearing scales only along the veins. The 

 abdomen is covered with red or orange scales, and is marked with transverse white 

 lines and a longitudinal row of black or bronze-colored spots. The tarsi are banded 

 with white, and the hind legs are covered with long black, white, and orange- 

 colored hairs. The sexes are quite similar, the male being more brilliantly marked 

 than the female, and with a narrower abdomen. 



Life History and Habits. 



The squash vine borer passes the winter as a full-grown larva. It is enclosed in. 

 the tough silken cocoon which it spins in the soil of squash fields, at a depth of 

 from one to six inches below the surface of the ground. Pupation occurs within 

 this cocoon in the spring, and lasts about three weeks. At the end of this time the 

 pupa cuts through one end of the cocoon by means of the horn-hke process on its 

 head, and wriggles to the surface of the ground, being aided in this endeavor by 

 the circles of spines around its abdomen. When it projects above the ground about 

 three-fourths its length, motion ceases, and very shortly the pupal skin splits back 



» MeliUia satyriniformis Hiibner fLepidoptera, j4)geriidie). 



