156 DISEASES OF CROPS. 



is allied to the hop mildew, a solution of iron sulphate 

 might prove a cheap remedy for this pest. The solution 

 could easily be distributed by the Strawsonizer. (2) Sul- 

 phur has long been employed for destroying the hop mil- 

 dew. From 45 to 65 lbs. of " flowers of sulphur " per acre 

 should be distributed, if possible, in hot and dry weather. 

 The sulphur should be distributed by means of the Straw- 

 sonizer. For the distribution of insecticides and fungi- 

 cides on ground crops, as well as hops, vines, etc., there 

 is no better machine than the Strawsonizer or Pneumatic 

 Distributor. 



(6) The Parasites of Lettuces {Lactuca sativa and 

 Lactuca altissima). 



The Lettuce Fly {Anthomyia lactucce) is allied to 

 the onion fly already described. The female lays her eggs 

 amongst the flowers, and when hatched the larvte feed on 

 the seed. 



Prevention. — (1) Burn the refuse from infested crops. 

 (2) Infested seed should be cleared from " the pupse or 

 little brown fly-cases " of this parasite. 



The Lettuce Root Fly {Aphis lactucce), as its name 

 suggests, seeks the juices of lettuce roots. It is of a 

 yellowish-green colour, and measures about one line in 

 length. The attacks of the insect are recognised by " the 

 plants drooping suddenly without any evident cause.'' 



Cure. — (1) "Drenching the ground round the lettuces 

 with strong soap-suds, soap-suds and tobacco-water, and 

 lime-water " is recommended for this purpose. (2) A 

 dilute solution of crude carbolic acid has also been recom- 

 mended for the same purpose. 



The Heart aitd Dart Moth {Noctua exclamation is) 



