1900.] BLADDER OR POCKET PLUMS 177 



almost certainly be able to give you the titles of the succes- 

 sive publications and prices, and also procure for you such 

 as are published. At one, time I worked a great deal on 

 vegetable galls, Cynips galls chiefly, but Phytoptus galls 

 I have always found so very troublesome in several points 

 of view that I have never worked on them more than I can 

 help. Very truly yours, 



ELEANOR A. ORMEROD. 



To Messrs. W. J. Coleman & Sons, Fruit, Pea, and Potato 

 Salesmen, Covent Garden Market. 



TORRINGTON HOUSE, ST. ALBANS, 



August i, 1900. 



DEAR SIRS, I would very gladly help you about the 

 moth-caterpillar attack on your potatoes, but I am afraid 

 that without caterpillar or moth I cannot name it. There 

 are very many infestations to potato of caterpillars, nearly 

 allied to what you will, I think, very likely know well as 

 the " Turnip grub." These are so numerous that it would 

 be quite hopeless for me to endeavour to name, merely from 

 description and the chrysalides; and even with the caterpillar 

 it would have been difficult (though I would \vith pleasure 

 have tried), on account of some of these pests greatly 

 resembling each other, and also some (identical grubs) 

 altering their colours completely as they moult. I should 

 have been glad to help you, but as these creatures are now 

 turning to chrysalides the attack is presumably nearly over 

 for the present. 



P.S. For general use in an attack of this kind the spray 

 that you have been using, which is very nearly equivalent 

 to the U.S.A. kerosene emulsion, is probably about as good 

 as you could try ; for I conjecture that you might not like 

 to try " Paris-green " ? Possibly this would not answer, 

 and for various reasons it being a ground crop as well as 

 the tuber a food crop it might not be desirable ; still, I 

 just name it. 



August 4, 1900. 



I am obliged by the fresh specimens of caterpillars 

 received this morning from your agent, Mr. Carswell, and 

 from these and the moths coming out to-day from the 

 chrysalides previously sent me, I am able to say that the 

 larvae are those of the Plusia gamma moth, popularly known 

 as the Silver Y-moth. I am not aware of these caterpillars 

 having been recorded as injurious to potato leafage, except- 

 ing in the year 1892, when I had information of two attacks 

 to this crop, in both instances from caterpillars migrating 



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