74 



Second letter. — Yonr letter of information iu regard to the wheat-destroying 

 insects in this community is at hand, for which you will accept the thanks of the 

 farmers of this county. You ask for the amount of damage done to the crop and how 

 long they have abounded iu our fields. It is believed uow that they have been in the 

 fields since early fall, and they still remain in great quantities in some fields. As to 

 the amount of damage done to the crops, after a careful estimate we place the damage 

 at 75 per cent, in one-half of this county, which iucludes the wheat belt. One-half 

 will be planted in other croj^s and the remainder will be about one-half stand. 

 There are some small crops of what is known as Faltz wheat; this is not hurt. 

 The rest of the crop is Mediterranean wheat. Can you give any reason for this ? 

 If so, you would oblige us. — [J. L. Fookes, Era, Cooke County, Tex., March 31, 1890. 



Reply. — I take pleasure in acknowledging the receipt of your favor of March 31, 

 together with newspaper clippings relating to the Wheat Louse {Toxoptera graminum), 

 and am much obliged to you for the additional information relating to the amount of 

 damage occasioned by it. As stated in a former letter, this insect has a wide range, 

 extending from Maryland to Texas, but has been heretofore comparatively rare. We 

 first received specimens in 1882, and it has since then been found near here in Mary- 

 land. It has also been reported several times from Indiana, and specimens have been 

 received from South Carolina. Tennessee, and Kentucky. 



We have received specimens at all times of the year, from January to July. There 

 is very little doubt but that this species is the one named above, which occurs com- 

 monly on the continent of Europe, where it is frequently destructive to grasses and 

 grains. In 1852 it was recorded to have been so abundant in the streets of Bologna, 

 Italy, as to cause great annoyance to the inhabitants. The fact that this pest is 

 with little doubt an imported one, and its excessive abundance over a wide area, 

 makes a knowledge of its habits very desirable, and it is hoped that during the com- 

 ing summer opportunity will offer to thoroughly study it in the field Any assist- 

 ance you can offer in the way of observations during the spring and summer will be 

 gladly received, and I shall also be glad to get additional specimens of the lice, for 

 the sending of which I inclose return franks. Many insect pests, after periods of un- 

 usual abundance, suddenly disappear, owing to the great increase of their natural 

 enemies, and this is especially true with the Aphides, or plant-lice, and has been fre 

 quently noted in case of the well-known Grain Aphis {Siphonophora avence). We may 

 therefore hope that this insect, which is a near ally of the Grain Aphis, will disap- 

 pear after the present year and not be troublesome again for some time. 



The immunity of the Fultz wheat is doubtless explained by some peculiarity of 

 its epidermis, or skin, which protects it against the lice or renders it distasteful to 

 them, and this protection is very probably caused by the presence of numerous 

 minute hairs, which prevent the louse from readily puncturing the stem with its 

 sucking beak. In \iew of this, would it not be desirable to grow the Fultz and 

 other wheats that experience may show to be little affected by this insect, rather 

 than the Mediterranean?— [April 7, 1890.] 



Third letter. — According to promise in my letter of the 8th instant, you will find 

 inclosed three of what is commonly called the Lady-bug, which is claimed by Mr. F. P. 

 Heare, of the Fair Plains neighborhood, to be the parent of the Toxoptera graminum. 

 In my letter of the 8th instant I gave you my reasons for doubting Mr. H's. statement, 

 and from an investigation made to-day I have much greater reason for doubting. In 

 one wheat field we saw a few straggling bunches of wheat which were thickly stuck 

 with the plant-lice, some of the smallest size, but not a Lady-bug could be found. 

 In an oat field where were a few scattering bunches that were left by the freeze of 

 some weeks ago, three Lady-bugs were found, but we could not find a single one of 

 the little pest. In another part of the farm we found another Lady-bug, but not one 

 of the pest. I then examined some oats on two other farms and found the little pests 

 in great numbers, but a diligent search failed to find a single Lady-bug. We have 

 interviewed a number of our best farmers and find them all inclined to doubt Mr. 

 Heare's opinion in regard to the Lady-bug. I have no tangible idea of where our 



