144 WILLOW. 



destroyed. To do it effectively, some one interested in the success of 

 prevention would do well to examine about the middle of July, and see 

 whether the caterpillars had gone through the change to the chrysalis 

 condition. It is important to be sure of this, for at first, if disturbed, 

 the caterpillars would be very likely to come out of their shelters, and 

 little good might be done by the gathering of their spun-up leaves. 

 But as soon as the change has taken place the bunches may be 

 collected and burnt. This would greatly lessen the amount of the 

 moths to be expected in August to start the second attack, and in case 

 of this occurring, any leaf-nests should be again picked off that are 

 observable on the Osiers about the end of September, or later ; or if it 

 is found they have fallen at the time of fall of the leaf, any measures 

 that are available should certainly be taken to get rid of these. 



What is really practicable for the purpose, probably only practical 

 Willow growers can say. Any chemical dressing, such as lime or gas- 

 lime, in quantity to injure the chrysalids might hurt the Willow roots, 

 or the chemical effect might alter the pliancy of the shoots. If the 

 state of the ground allowed the surface rubbish to be scraped together 

 and burnt before the ground was cultivated in whatever method is 

 requisite, this would get rid of a great many; and it would be well also 

 to search on the Willow stools, at the bottom of the cut-back shoots, 

 for what may have lodged there. 



With regard to remedy when the caterpillars are ravaging on the 

 shoots, the matter is very difficult. Miss Sturge, in her letters to 

 myself, mentioned, in reference to hand-picking, that the attack was 

 really terrible, so that hand-picking only cleared some amount of the 

 many thousands. 



Probably the only effective way to treat them would be to spray 

 with Paris-green, from a Knapsack Sprayer, which could be carried on 

 a man's back, and worked by him by means of a hose.* Where there 

 are objections to the use of Paris-green, it would be worth while to try 

 washes of a mixture of soft-soap and mineral oil, which could be pre- 

 pared at home or purchased. The mixture sold under the trade name 

 of "Anti-pest," by Messrs. Morris, Little & Son, Doncaster (see ante, 

 p. 37), would save much trouble in mixing. 



Water alone, if cold, sometimes does good in clearing caterpillars 

 in hot weather, and this would also be beneficial in clearing the 

 Cuckoo-spits mentioned at p. 141. These insects are so generally 

 known that they do not seem to require a special notice. Most of us 

 know tliem in their fully developed state as little greyish or brownish 



* All requisite details are given in my pamphlet on ' Paris-green,' procurable, 

 price 2d., from my publishers, Messrs. Simpkin & Co., Stationer's Hall Court, 

 London, E.G. ; or I would have pleasure in giving it myself to any applicant. 



