124 



mission has been sent to you in respouse to your former letter ; it contains in its 

 first part, in treating of the Cotton Worm, an elaborate chapter on the application 

 of arsenical poisons to the cotton plant and upon referring to that portion of the 

 Report (pp. 136-153) you will find full particulars regarding the points you asked me 

 in your last letter. I have pointed out that a timely application of Paris green or Lon- 

 don purple, not only protects the plants from the Cotton Worm, but is at the same 

 time the best remedy that can be recommended for the destruction of the young Boll- 

 worms before these enter the bolls. The report was published in 1885 and since that 

 time no new discoveries have been made regarding the mode of application of these 

 poisons. It will be necessary, therefore, to reply but very briefly. 



(1) London purple can not be said to be better than Paris Green, but it is a good 

 substitute and much less expensive. (See fourth report, pp. 143 and 151.) 



(2) This depends entirely upon circumstances: Water is often not handy, and small 

 planters are liable not to have any spraying apparatus on hand. For these reasons 

 the dusting method is often resorted to, but it is much more expensive on a large 

 scale than the spraying method. In a general way it may be said that the spraying 

 method is very much preferable, especially in dry or tolerably dry weather, while in 

 very wet weather the dusting method gives the most satisfaction. 



(3) Any of the improved force pumps which are now in the market, in connection 

 with a good atomizing nozzle, and more especially the " Riley " or " Cyclone Nozzle," 

 which is described on pages 211-219 of the fourth report. For the dusting method 

 several simple hand dusters can be obtained, or, if nothing else be at hand, a broad 

 sieve with a double layer of fine muslin covering the botton will answer the purpose. 



(5) NeitherParisgreen nor London purple, being compounded substances, have chem- 

 ical names ; the analysis of London purple is given on page 149 of the report. Neither 

 are soluble in water though London purple has a larger proportion of soluble matter. 



The chief requirements in successful coping with either of the worms are : (1) 

 Watchfulness for the first appearance ou the under side of the leaves, and early spray- 

 ing before the leaves become seriously eaten or ragged ; (2) spraying as far as possi- 

 ble on the under side of the leaves and as finely as possible in order that the poison 

 may adhere and not be washed off, — [June 19, 1890.] 



The Tent Caterpillar. 



The apple trees in this vicinity are greatly overrun by the Tent Caterpillar, the 

 larvae of '^ Clisiocamjpa americana'^ and much damage is being done to orchards and 

 isolated trees. In a recent walk I counted over one hundred apple trees completely 

 denuded of buds and leaves, while on one half-grown tree I counted eighty-nine of 

 their nests. About June 1 there were hosts of the larvse everywhere — on fences, 

 bushes, over our gardens, on windows, doors, and trying to gam an entrance at every 

 opening into our houses. For a time it seemed like a new edition of an " Egyptian 

 plague," but the cold stormy weather has destroyed them, or else they are re^dy to 

 make the change into chrysalid state, for at present they are not troublesome. Our 

 trees blossomed well, but this pest will cause a change in the crop estimates of the 

 early spring. — [Lewis E. Hood, Ashland, Mass., June 12, 1890. 



An Orthesia on Coleus. 



By to-day's mail T send you a sample of Mealy Bugs which have caused me a great 

 deal of trouble on our Coleus. I think I got them from P. Henderson's last winter on 

 some new Coleus. They propagate very fast. I got rid of millions of them by dipping 

 the plants in a solution of fir-tree oil, but it was an expensive job. Do you know of 

 a better remedy ? Is it a new bug or an old one ? I have never seen it before. I am 

 much obliged to you for the advice you gave me last winter. — [Charles Freund, Rye, 

 N. Y., June 16, 1890. 



Reply. — The specimens received belong to the Coccid genus Orthesia. The insect 

 is apparently a new one and has not been hitherto described. It has been received 



