GRAMINEOUS CROPS. 85 



Prevention. — (1) Good cultivation and liberal manuring 

 to produce healthy and vigorous crops. For suitable 

 manures (for various gva,BS lands), see the author's book, 

 Manures and their Uses, p. 42. (2) A thorough drain- 

 age of damp (and in fact all) lands has a tendency to 

 lessen the attacks of this pest. (3) The "brush-harrow" 

 is useful for preventing the deposition of eggs. (4) Star- 

 lings and rooks destroy large numbers of the larvse of 

 Tipula. "Perhaps there is no bird that does so much 

 real good to the husbandman as the starling (Sturnus 

 vulgaris), for it feeds upon the most destructive grubs 

 and insects that exist ; and therefore this more than com- 

 pensates for the cherries and elderberries which it eats " 

 (Swaysland). (5) In the case of old pastures, deep 

 ploughing buries the larvae and eggs, and thereby destroys 

 them. (6) Rolling infested grass lands (at night) with 

 a Crosskill or Cambridge roller destroys thousands of 

 grubs. 



Cure. — (1) Dressings of quicklime or gas-lime have 

 proved useful. (2) Mr. A. Smetham, P.C.S., has shown 

 that " a solution of sulphate of copper (blue vitrol) killed 

 the grubs in about eight to twelve minutes. Sulphate of 

 iron (green vitrol) was more rapid in its effects." (3) 

 Salt has been spoken of by some writers ; but it has been 

 shown that the larvae of Tipvla are not killed after an 

 immersion in strong brine for twenty-four or thirty-six 

 hours. This is due to their thick and very tough integu- 

 ments. 



The Eelworm of Grasses {Tylenchus devasta- 

 trix) has already been described. It attacks certain 

 meadow grasses. Amongst these are the following : An- 

 thoxanthum odoratum (sweet vernal grass), Poa trivialis 

 (rough stalked meadow grass), Poa nemoralis (wood 



