252 



EXTRACTS FROM CORRESPONDENCE. 



Late Autumnal Occurrence of Mites in Great Numbers. 



Friday, November 7, was a rainy day, and at night a very heavy raiu-fall occurred ; 

 on Saturday it rained in light showers, grew cooler in the evening and froze hard 

 at night ; on Sunday morning a lady riding along asked her husband what that curi- 

 ous sawdust-like stuff was that was scattered along the roadside so beautifully. 

 On examination it was found to be a very small, red-legged, spider-like insect, and 

 that it was everywhere— field, roadside, garden — covering the country for miles. I 

 think it was not more than one-half as large as the tiniest new-born spider I ever 

 saw, although I do not remember to have seen one just from the egg. They were 

 more noticeable in pools and puddles of water — perhaps from their insignificance in 

 size — where they appeared in patches, few or no individuals appearing singly. 



Viewed through a microscope of low magnifying power they appeared to be shaped 

 somewhat like a grand-father grav beard or daddy-long-legs; eight bright red legs 

 dangled from their black bodies; occasionally a sort of drab-colored individual might 

 be seen; two white opaque specks on either side, which I fancied might be eyes, 

 adorned one end of the body and a very curiously-shaped dull- red spot the other; no 

 appearance ol any web was discernible; they were not at all active, and in about a 

 week the legs began to turn white and drop off, probably because the insect was dead. 

 As none were to be found on our farm after Sunday, and as 1 am a very busy woman, 

 I had no time to study them. Being very much interested in them, however, I have 

 ventured to write you, hoping that you will kindly tell me wliat you think about this 

 strange insect, where they so mysteriously came from, and whether they will be likely 

 to appear again, and, if so, will it be to our injury ? * * * — [Augusta B. Wisner, 

 Tecumseh, Lenawee County, Mich., November 27, 1888.] 



Reply. — Your letter of the 27th ult., giving an account of the occurrence of a small, 

 red-legged, spider like insect in great numbers in your vicinity after a cold snap, 

 has been received. I am very sorry that you did not save specimens, as I am not 

 aware that anything precisely similar has before been recorded. Your description is 

 quite careful, but you do not give us a definite idea as to size. * * * If you can 

 possibly secure specimens, please do so and forward them to us. — [December 4, 1888.] 



Second letter. — Your letter of December 4 duly received. In answer I will say 

 that I have been so fortunate as to obtain a few specimens, which I shall this day 

 mail to you. Although they have disappeared from our immediate vicinity, I find 

 that at my brother's a great quantity of them remain, and they were observed one 

 day last week crawling all over the buildings and even came into the house and got 

 into the milk. I find this morning that many that I gathered for you must have es- 

 cajied, but I hope enough are left for you to determine their nature. They were in a 

 deep bottle, and I did not dream of their getting out. I have not changed the water 

 from which I took them, fearing their health mioht sufi"er. In a letter from a sister 

 living in Tuscola County, she says : '' I have not seen the little insects you speak of, 

 but others have here, or out of town. It does seem strange. Mysterious are the 

 works of Providence." Now there is little doubt that it is the same insect, as I wrote 

 her describing it ; and as she lives at a distance of about 160 miles, you will see how 

 widely spread it appears to be. * * ""—[December 11, 1888. 



Reply. — Your letter of the 11th instant, accompanying a bottle containing speci- 

 mens of the mite concerning which you had previously written us, has been received. 

 I am very glad to get these specimens. The material is so rotten that it is difficult 

 to study, but the species is evidently near the genus Tetranychus, which is the genus 

 to which the common Red Spider of our greenhouses belongs. Concerning the habits 

 of this particular species which you send I can say nothing, except that all of the 

 species of the genus, so far as we know, feed upon the leaves of plants, and your spe- 

 cies may have been very common on grass or low herbage. — [December 18, 1888.] 



