SQUASH DISEASES AND PESTS 



1909 



Squash, simblins and pumpkins are the 

 favorite food plants, althougli other cu- 

 curbits, like cucumbers and cantaloupes, 

 are sometimes attacked. 



Several borers may occur in a single 

 squash plant and their presence remain 

 unobserved until the whole plant sud- 

 denly withers and dies, seemingly in a 

 single day. The reason for this sudden 

 collapse is because the borers, feeding in 

 the main stem, eventually girdle it com- 

 pletely, thereby cutting off the flow of 

 sap from the roots to the branches, and 

 the plant, thus suddenly deprived of 

 food, rapidly withers under the hot July 

 or August sun. If such plants are ex- 

 amined, quantities of powdered, yellow- 

 ish excrement will be found around the 

 stem, having been forced out of the feed- 

 ing channels made by the borers. These 

 dying plants usually contain several 

 borers — a dozen or more is not an un- 

 usual number — for plants are often able 

 to survive the presence of only three or 

 four unless they happen to girdle the 

 stem near the roots. Severe injury may 

 usually be prevented by learning to rec- 

 ognize the first sign of borers, evidenced 

 by the yellowish excrement around the 

 stem, and removing them in the manner 

 to be described later. 



Distribution 



Its distribution now extends from Can- 

 ada southward to the Gulf states, and to 

 the West at least as far as the Rocky 

 mountains. It also occurs in Mexico, 

 Central and South America, and is 

 thought to be of tropical origin. 



Description 



Parent Moths 



The adult or parent stage is a hand- 

 some moth belonging to a family known 

 as clear-winged moths. The front pair 

 of wings are opaque, olive-brown in color, 

 with metallic-green reflections; the hind 

 wings are clear and transparent, with 

 black veins and a wide bronzy-green 

 fringe of hairs. The hind pair of legs 

 bear a heavy fringe of hairs, those on 

 the outer edge orange or reddish, while 

 the inner fringe is black. The abdomen 

 is conspicuously orange or red, with black 

 or bronze markings. Altogether, these 

 moths present a striking appearance. 

 (Fig. 1.) They are readily recognized as 

 they fly about squash plants, depositing 

 eggs during the day, and may be easily 

 captured in a butterfly net, or knocked 

 down with an evergreen brush or simi- 

 lar weapon. 



Eggs 

 These are dull reddish-brown in color, 

 oval, about one-twenty-fifth of an inch 

 in length, and when magnified, show a 

 surface composed of many five, six, or 

 seven-sided areas. The eggs are glued 

 to the plant and flattened on the attached 

 side. 



Larvae 



Larvae or borers are robust white, 

 grublike worms (Fig. 1), with the body 

 distinctly segmented. Average length is 

 about one inch. 



Cocoons and Pupae 



When the borers are fully grown they 

 desert their feeding burrows, tunnel an 



•■ 1 



Fig. 1. Squash Vine Borer 



(1) Adult. (2) Larvae and pupae, 

 showing manner of escape. 



(3) Empty pupae shell 



