1909.] The Insect and Allied Pests of the Hop. 555 



between three and four barrow loads, and is more easily 

 pushed than an ordinary barrow, and if the rail can be laid 

 with a slight fall to the dungstead, the load may run out and 

 empty itself. Separate buckets are used for the carriage of 

 the manure and the food. 



THE INSECT AND ALLIED PESTS OF THE HOP. 

 Fred V. Theobald, M.A. 



South Eastern Agricultural College, Wye. 



The hop is not subject to the attack of very many insects 

 and allied creatures. Forty-two species only of true insects 

 or hexapods — six-legged animals — have been found feeding 

 on the hop in Britain, but of these only seven are of any 

 general importance, namely, three kinds of Wireworm, or 

 larval Click Beetles, the Hop Aphis, the Strig Maggot, the 

 Clay-coloured Weevil, and the Frog-hopper or Jumper. 

 Others, such as the Needle-nosed Hop Bug, Fever Flies, Otter 

 Moth, &c, are only of occasional and local importance, and 

 several recorded here are isolated attacks only. Only one 

 Acarid occurs in sufficient numbers to do any harm, namely, 

 the Red Spider. Two Millepedes are found in hop roots, but 

 some growers still doubt if they are the cause of disease, and 

 say they follow upon it. 



One very important hop pest is the Eelworm (Heterodera 

 scJiachtii), causing "nettle-head." It is probable also that the 

 Common Eelworm (Tylenchus devastatrix) plays some im- 

 portant part in the dying back of hops. It must take years 

 of patient research, however, before the part they play can 

 be definitely settled. In all cases of Tylenchus attack in 

 hops which I have seen in recent years the fungus Fusoma 

 parasitica has been present, and it is a question whether the 

 latter is the direct cause of disease or whether the Eelworm 

 makes the plant susceptible to this fungus. With the insect 

 and acarid enemies of the hop, growers can deal, but with 

 eelworm attack they are quite unable to stem the rapid tide 

 of disease that is now flowing. Science can do nothing until 

 much more is known of the bionomics of these minute 

 nematode worms. 



The notes given below are merely a few of those collected 



