INSECTS INJURIOUS TO CUCUMBER, MELON, ETC. 



169 



jure a plant so that no fruit will mature. Injury is most notice- 

 able near the bases of the stems, where in course of time the 

 vine becomes sev-ered from the roots. 



The parent insect (fig. 11 1, 0) is a beautiful clear-winged 

 moth. The fore-wings are lustrous olive-brown, with metallic 

 green reflections, and expand about an inch and a fourth. The 



Fig. 112. — Squash-vine borer, a, Egg as seen from above; b, same from the side 

 showini: sculpture; c, sculpture of egg greatly enlarged; d, newly-hatched larva; e, 

 half-grown larva; /, head of same from side; g, head of mature larva from above, a, b 

 and rf, Much enlarged; e, /and ^, less enlarged. (Author's illustration, U.S. Dept. Agr.) 



abdomen is marked with orange or red, black and bronze, and 

 the hind-legs are fringed with long hairs. 



The larva is soft, whitish and grub-like. Mature larvae 

 measure about an inch. In the District of Columbia full-grown 

 larvae occur as early as the middle of July and as late as the 

 second week of November. After attaining maturity the 

 larvae enter the earth to the depth of one or two inches and 

 form cocoons (fig. 11 1, /) constructed of silk and coated ex- 

 ternally with fine particles of earth. Observations indicate 

 that this species is practically single-brooded northward; that 

 there is a tendency to two broods in New Jersey; that in the 

 District of Columbia the species is partially double-brooded, 

 and that in the Gulf States it is fully two-brooded. 



