thp: hop grub — its habits. 



heads," I am informed by growers, were quit* 1 common this spring. The 



heads had been opened and the larva detected, but the parentage was 

 almost universally attributed to a ''green fly" mentioned, but not more 

 nearly described in several agricultural papers. This fly, as near];, 

 can make out from the description of growers, is a Syrphus, and prob- 

 ably the pareut of the larva found afterward destroying the hop aphis. 

 At any rate, it is not the parent of this '-tip worm," as the insect has 

 beeu called. Not all "muffle heads" are caused by this larva, how- 

 ever, as will be hereafter pointed out. 



When the insect attains a length of about half* an inch or slightly 

 less, it leaves the tip, drops to the ground, and, entering the stem at the 

 surface of the vine, feeds upward, interrupting the growth of the vine and 

 lessening its vitality : the larva now changes color, and becomes a dirty 

 white with a strong, deep reddish tint, apparently proceeding from be- 

 neath the surface of the skin, and with numerous black spots. As the 

 vine grows, it becomes hollow and hardens, and the more rapidly as the 

 free flow of sap is interrupted. The larva, now about an inch in length, 

 and still slender, burrows downward to the base of the vine at its junc- 

 tion with the old stock, and, eatiug 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 "grab," and the lavages caused by it are 

 most noted. 



The journey from the stem to the ground is made in the beginning of 

 June, and by the 21st of June, while 1 found many larva? in the ground 

 about the roots, none were found in the stems, though traces of their 

 work were everywhere abundant. 



The larva now is mainly a sap feeder. It eats a small hole into the 

 side of the stem just below the surface and just above the old root, and 

 grows fat rapidly on the juices that should nourish the plant. As the 

 sap seeks courses to enable it to reach the upper part of the viue un- 

 molested, the grub enlarges its opening until he sometimes severs it en- 

 tirely from the parent root, and the vine dies. In other cases it is left 

 barely attached to the root, and continues a precarious existence, yield 

 ing few or no hops. Occasionally an exceptionally healthy vine will en- 

 tirely recover from a serious attack of "grub. 7 " By the middle or the 

 20th of July the larva? are full-grown and ready to enter the papa state. 

 They are now about 2 inches in length, fleshy, unwieldy, and very Blow 

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

 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. 



About the 20th of July the pupa is formed in a rude cell close to the 

 roots of the plant, upon which, during its larval existence, the insect \\h\. 

 The pupa is an inch or slightly more in length, stout, cylindro-conic, and 

 of a deep brown or blackish color. In this condition it passes the win- 

 ter, though, as before remarked, a few specimens appear in the fall. 

 Whether these latter hibernate or whether they perish, 1 have not been 

 able to ascertaiu, though the latter seems the mora likely. 



