Nos. 1-6 and 11 and 12, Gout fly, grub, and pupa—natural size and magnified; with infested stem; 7, 8, 9 and 10, parasitic ichneumon flies, natural size and magnified.
FIG. 17.—GOUT FLY, RIBBON-FOOTED CORN FLY, CHLOROPS TÆNIOPUS, MEIGEN.[[61]]
August 28, 1894.
Your packet of infested straw came safely to hand this morning and I am very much obliged to you for kindly taking all this trouble. I have repacked the Hessian fly straws, winding a thread over the place of deposit of the puparia on the barley straw for fear they should get from under the sheathing leaf and be lost. I am sure Dr. Ritzema Bos will be very grateful for the help, and also for its coming so promptly.
Thank you also for the Chlorops (Gout fly) specimens; they were particularly acceptable just now, for, if all is well, Professor Riley means to look in early next week before he returns to the U.S.A., and I think he would like to see them.
April 26, 1895.
If I am not troublesome I should be very greatly obliged if you would tell me anything as to the methods commonly used for keeping off attacks of the Forest fly, Hippobosca equina, which is such a special pest in the New Forest to horses not used to it. I mean the thick made fly of which I enclose a figure (18), natural size and magnified, which deposits an egg-like puparium or chrysalis case in the hair of the horses, from which case the fly presently comes out. I believe you will know exactly the infestation I refer to, and any information which you may be good enough to give me, as to how to prevent it coming at horses and settling on them, I know would be quite sound and reliable. I am receiving so much application for information about the habits, &c., &c., that I feel sure my best plan will be to issue a leaflet as soon as possible with figure included at the heading. I have, I think I may say, far more in the way of description and nature of the fly than can be needed, but it would help me very much indeed to have a recipe for any application which was really known to answer in keeping the attack off riding horses. I am sure you would allow me to add this to my leaflet, acknowledged to you. I make no doubt quantities of things, especially of the nature of soap or soft soap (not caustic) or lard, and a little paraffin or sulphur, would with careful attention keep the flies from congregating permanently, but the thing in hand is to prevent them coming at the horses and causing dismal downfalls! I have heard lately of a plan of rubbing horses with paraffin—very efficacious, I should expect, but not the thing to benefit the clothes of the riders!
1 and 2, natural size and magnified from life; 3, pupa removed from puparium (after Réaumur); puparium, natural size and magnified, before complete coloration.
FIG. 18.—FOREST FLY, HIPPOBOSCA EQUINA.
Wednesday night, May 1, 1895.