1909.] The Insect and Allied Pests of the Hop. 557 



near them. Hence wire worm are most abundant in per- 

 manent pasture and in clover-ley. 



The ova hatch into wireworms, as shown in Fig. 8, PI. 1, 

 and these feed upon the roots for three, and in some cases 

 for four, and even five years. They feed all the year round 

 when the weather is not too hard. In sharp and prolonged 

 frost they may burrow deep into the soil and remain dormant, 

 but come up again as soon as the land thaws. Eventually, at 

 the end of three, four, or five years they burrow deep down 

 during the autumn and pupate, and appear above ground as 

 Click Beetles in early summer. The wireworms can at once 

 be recognised by their yellow, shiny, wiry appearance, and by 

 having three pairs- of jointed legs in front and a swelling 

 below towards the tail end. They are frequently confused 

 with Millepedes, or Thousand Legs. 



Treatment and Prevention. — No substance that can be used 

 on a large scale is known to kill wireworms in the soil. They 

 may be driven or drawn away by such substances as Vaporite 

 or rape cake, but they are not killed, and as soon as the effects 

 of the substances have gone they return to the plant roots. 



In hops the only way to get rid of wireworm is the old 

 plan of enticing them away from the stocks by setting pieces 

 of potato, carrot, beetroot, or mangold in the ground close 

 to the hills, and then collecting from these traps and killing 

 them. Some success has been obtained by the use of 

 bisulphide of carbon injected into the soil around the hills, 

 but the varied effect of moisture on this fumigant makes it 

 extremely uncertain in action in this country. The cultiva- 

 tion of mustard in hop gardens and feeding off with sheep 

 will do some good in respect to this pest. 



The beetles may also be readily trapped by placing here 

 and there in the alleys heaps of clover or lucerne in May and 

 June, covered over with a few tiles or boards to keep each 

 heap in its place. The beetles go there, and may be easily 

 collected during the day. When we consider the length of 

 life of wireworms and the difficulty of killing them, this 

 plan is well worth considering. The use of rape cake or 

 meal is not recommended, as it undoubtedly attracts the 

 beetles, so that great numbers of eggs are laid, and at the 

 best it only draws the insects away for the time. 



