20 



Circular 107 

 On the Cucurbs 



The problem of lice control on melons and cucumbers appears 

 to differ from that on most other vegetable crops in that not only- 

 may the infestation be initiated early while the plants are yet small, 

 when it may be destroyed by the use of a good orchard sprayer, but 

 after the vines are well grown they may become heavily and dan- 

 gerously infested by lice that migrate from surrounding weed fields 

 that are cut or have become too hard for further use. The last type 

 of infestation should be met by turning the vines over ahead of the 

 operation and thoroughly wetting the lice with a good orchard spray- 

 er and then returning the vines to the normal position. Of course, 

 after the vines have interlaced, treatment by anything other than a 

 knapsack or other hand sprayer is out of the question. 



Pig-. 14 



Knapsack and Compressed Air Sprayers With Proper Sort 

 of Extension Rod 



On Lettuce 



Lettuce grown in cold frames or in greenhouses may become ser- 

 iously infested. The lice may be destroyed in this case by use of 

 tobacco fumes as recommended for tomatoes. For lettuce in the 

 field, which becomes infested, there is not at present any remedy 

 worked out. 



