INSECTS IXJURIOUS TO THE HOP-PLAXT. 271 



still slender, burrows downward to the base of the vine at 

 its juncture with the old stock, and eating its way out, 

 completes its growth as a subterranean worker; it is in 

 this state that it is best and most widely known as the hop 

 ' grub,^ and the ravages caused by it are most noted." * 



The larvae have mostly left the stems by the last of June 

 and henceforth are mainly sap-feeders. Eating into the 

 stem just below the surface of the ground and just above 

 the old root, they rapidly grow fat upon the juices of the 

 plant. These openings are gradually enlarged so that very 

 often the stem is entirely severed from the root or is so 

 slightly attached that the plant is badly stunted and yields 

 few, if any, hops. The larvj^e become full-grown from 

 the middle to the 20th of July and are then ^' about 

 two inches in length, fleshy, unwieldy, and very slow in 

 their movements; they are of a dirty white color, speckled 

 with line, brownish elevated tubercles, each furnished with 

 a single stout hair; the head is brownish and corneous, as 

 is also the top of the first segment." (1-c.) 



The larva3 now transform to pupse in rough cells, close 

 to the roots which they have infested, and the adult moths 

 emerge during August or September, or the following 

 spring. The adult moths are found to be most beautifully 

 marked upon close examination, though not of a striking 

 appearance at first sight. ' ' The general color is a rosy 

 broAvn, paler at the extremity of the wings. The darker 

 central portion is shaded with dark velvety bronze and 

 marked with two dull-yellow spots. The fore wings are 

 divided into three areas by narrow oblique transverse lines, 



* "Hop -insects," Dr. J. B. Smith, Bull. Xo. 4, o. s., Div. Ent. 

 U. S. Dept. Agr. 



