339 



Eeply. — It is not common for locusts to be carnivorous, liut instances such as thaV 

 which you mention are occasionally observed not only with locusts but with other 

 plant-feeding insects. — [October 2, 1890.] 



Citheronia injuring Cotton. 



I send you a worm that has this year for the first time made its attack on the cotton 

 plant. Please examine him and tell us something about him and what we are to 

 expect from him in the future. He has destroyed considerable cotton plant in some 

 places. He attacks and eats the plant much the same as the small cotton worm does, 

 only he eats stalk as well as leaves — [D. C. Scarborough, Natchitoches, La., October 

 2, 1890. 



Reply. — The caterpillar which you send is the so-called Royal-horned Walnut 

 caterpillar, and is the larva of a handsome moth known as the Regal Walnut 

 moth {Citheronia regalis). This caterpillar has been recorded as feeding upon quite 

 a variety of trees and shrubs, among them walnut, hickory, butternnt, persimmon, 

 and sumach, but so far as known it has never been recorded as feeding upon cotton. 

 It is a comparatively rare s[»ecies and has never been recorded in suflScient numbers 

 to do any appreciable damage. Its large size and brilliant coloration render it easily 

 seen, and the few which will be found upon cotton plants may be killed by hand with- 

 out taking any other precautious. — [October 6, 1890.] 



Gelechia cerealella in Virginia. 



We send with this sample of wheat raised in Virginia near Gunston which has a 

 new kind of a bug in it to us. At first we thought it was the black weevil, as it eats 

 out the heart of the grain, but as you see it produces a fly. We are finding it in a 

 large number of samples offering, but have never had quantity enough to tell how it 

 will aft'ect the flour, or if the grain will heat if in bulk as weevil will do, — [W. H. 

 Tenney & Sons, Georgetown, D. C, September 18, 1890. 



Reply. — The pest is the Angoumois grain-moth {Gelechia cerealella). You will 

 find an account of this insect in the annual report of this Department for 1884, pages 

 345 to 355, which contains a digest of the information which we have concerning it. 

 We are not informed as to whether the grain will be more apt to heat in bulk if at- 

 tacked by this insect. The quality of the flour, however, is unquestionably damaged 

 by its presence in numbers, and it will pay you to adopt stringent measures to pre- 

 vent this insect getting a fo ithold in your mills. The best method of destroying it 

 will be to quarantine all infested grain in tight bins and disinfect it by means of the 

 carbon bisulphide treatment. Of this substance not more than 1^ pound to a ton 

 should be used.— [October 7, 1890.] 



Appearance of wheat infested with Hessian fly. 



* * * In my report on Hessian fly I shall deal with the effect of larvae on young 

 plants. I think you have never quite agreed with me as to the appearance of affected 

 plants. I send to-day two boxes, one of injureil and one of healthy plants. Now 1 

 have not myself touched these, but Professor Plumb went to the field with me, dug 

 up what I told him to. I send these, A being infested and B healthy plants. This 

 is pure guesswork. I want you to look these over and tell me the result. How many 

 mistakes have I made?— [ F. M. Webster, La Fayette, Ind., September 20, 1890. 



Reply. — Of the lot A (infested plants) 37 were infested and 1 was healthy. Of the 

 lot B (healthy plants) 6 were infested and 35 healthy. The difference iu the general 

 color of the two lots is quite marked but I strongly suspect that the common wheat 

 rust has something to do with this, since the yellowiug of the less infested plants is 

 evidently due to the greater abundance of rust on them than on the plants more 

 attacked by Hessian fly. » * * The stooling or fasciatiou of the plants is just 

 what one would expect, as this tendency to stooling is the comuioii icsult of any 



