3 



melons and cucumbers when the other preferred crops are availa- 

 ble. The larvae bore through the stems from the roots to the base 

 of, and even through, the leaf-stalks, and sometimes attack the fruit 

 both of squash and muskmelon. Larvae have also been observed on 

 the wild balsam apple {Ecliinocystis lobata), which is probably a 

 natural food plant. 



Injury is greatest to Hubbard, marrow cymblins, and other late 

 varieties of squash, and is apt to be more acutely felt in small 

 gardens than when crops are grown for market. Even if the plant 

 survives attack it may not bear fruit, and often the grower loses a 

 large proportion of his crop year after year. Not infrequently entire 

 crops are destroyed. 



NATURAL HISTORY. 



This species is injurious only in the larval form. Although the 

 larvae are familiar objects to all squash growers, the moths are not 

 generally recognized as the parents of these pernicious borers. 



The moths, unlike most others, fly only during the daytime and in 

 the heat of the day. Toward twilight they become less active and 

 may be seen sitting quietly on the leaves of their host plants. Both 

 when in flight and when at rest the moths are singularly wasp-like 

 in appearance. 



Time of appearance of the moth. — Approximately it may be 

 stated that the moth appears as soon as the vines are sufficiently 

 advanced to serve for oviposition and the subsequent subsistence of 

 the borer larvae within their stems. Indications are that as far south 

 as the District of Columbia the moths make their first appearance in 

 the field sometime in May or at least early in June, as larvae nearly 

 matured have been found by the middle of July. In New Jersey, 

 according to Dr. J. B, Smith, the moths are abroad at or soon after 

 the beginning of June ; on Long Island from the middle to the last 

 of June. In Massachusetts, according to Harris, they appear about 

 the plants the second week in July. We thus have considerable 

 variation in time of earliest appearance dependent upon season and 

 locality, a variation to be expected in a species of so wide a range. 



The egg and oviposition. — The eggs, which are oval and dull red 

 in color, are laid upon all parts of a plant, from the roots to the buds 

 and petioles, but chiefly along the stems, though in some varieties of 

 squash, it is said, nearer the base of the stem than otherwise. Ovi- 

 position is very rapid, the moth flitting from hill to hill leaving an 

 egg in each. A single moth may lay as many as 212 eggs. The 

 eggs hatch in from six to fifteen daj's after they are deposited, and 

 the larvae are said to attain full growth four weeks or more later. 

 This period will undoubtedly vary in different temperatures accord- 

 ing to the season of the year when oviposition takes place. 



