413 



A Tomato Root-louse. 



* * * Two years ago, while iu the employ of the Atchison, Topeka and Santa 

 Y6 Railroad, I happened, while I was visiting Albuquerque (about 100 miles south of 

 Santa F^, in the Rio Grande Valley), to meet a French gardener, who mentioned to me 

 that a peculiar disease had attacked his tomatoes, and that out of six hundred plants 

 only two had escaped alive. Last year, in June, I was at a village named Los Cor- 

 rales, 12 miles north of Albuquerque, on a visit of some days' duration at the viue- 

 yards of another French gentleman named Louis Alary, when I noticed in his garden 

 a number of tomato vines that appeared yellow and sickly ; in fact, many of them 

 already iu full bloom were dying. I dug up several of the vines, but discovered no 

 apparent cause for the malady, except that the rootlets seemed to have shrunk and 

 were drying up. I attributed this to the corroding effect of the alkaline salts (the 

 Mexicans call them salitre — saltpetre), which the water of the Rio Grande, used 

 for irrigation, holds in solution. 



Some days since, at the place of Mr. Valentine Herbert, a German gardener of Santa 

 F^, I remarked the same peculiar appearaaco on his tomato vines, and he told me 

 that he had already dug up many of them which had the same disease, which had 

 been noticed by him for the first time in 1888. As the water in Santa F6 contains no 

 alkali, being formed of pure snow and spring water that flows down from the adja- 

 cent mountains, my theory was at fault. I took a spade and dug up a few vines. 

 In examining the ground and the roots I found what I now believe to be the cause 

 of the disease ; quantities of a large white root-louse. It is when full grown about 

 the shape and size of a flaxseed, and moves about quite briskly when disturbed. 

 I have preserved about a dozen of these insects in a small vial in a mixture of alcohol 

 and water, which I shall send you, and also some roots of the diseased vines. I 

 feel convinced that this I'oot-louse is the destructive agency which kills the vines, 

 for no plant attacked ever survives to bear fruit. — [John F. Wielandy, Santa F6, 

 New Mexico, August G, 1890. 



Reply. — The insect on the roots of tomato which you call a Phylloxera is a Mealy 

 Bug of the genus Dactyloplns, and probably a new species. What yon have to say 

 concerning the damage done by this iusect is very iuterestiug and entirely new to 

 us.— [August 27, 1890. ] 



Ticks from Texas. 



I shall send you by to-morrow's mail a box containing insects. You will find in a 

 little square bottle four different kinds of ticks, if size, shape, and color are essen- 

 tial to make a species, but my neighbors think those little ones are the young of the 

 old ones. I dropped some alcohol on them to keep them from decay. They are a 

 terrible pest. The largest one is the most common ; the one with a white spot on its 

 back is called Scotch tick ; it gets into the horses' cars and causes them to lop down. 

 The third size is called " Seed tick;" it is very abundant in hot weather. The fourth 

 size is generally called Jigger ; it is very irritating when it gets on anybody. The 

 two largest kinds are active all winter in southeastern Texas, and are the cause of 

 the death of many a poor cow. Old axle grease seems to be the best remedy. — [F. 

 W. Thurow, Hockley, Harris County, Texas, August 22, 1890.] 



Reply. — The two large ticks are the male and female of Ambhjomma maculatum 

 Koch. Those with the white dot are Amblyomma unipunctatum (americana Koch) 

 Pack., female, and the little ones are the young of the latter species. — [August 30, 

 1890.] 



Flights of Dragon Flies. 



Please accept my sincere thanks for your interesting letters in answer to my ques- 

 tions about the Dragon Flies. Yesterday they were on the wing again and flying iu 

 the same direction as always before. I send you by mail a couple of them. You ask 

 if these flights have boeu noticed before. I have often noticed them, and for many 

 years back, but as I made no memorandum of the occurrences I can not say positively 



