on ilies 
215 
planation in any text-book, newspaper, or public document.{[—Joshua Wood, Mis- 
souri, January 17, 1891. 
Repty. * * * The peculiar object which you so well describe was a mass of 
the little larve of the genus Sciara, the adults of which are small midges or gnats 
with feathery antennie. These insects have long been known to have this gregari- 
ous habit and are often found in dense batches under the bark of trees. When about 
to transform to the pupa state they congregate in great numbers, forming processions 
like that which you describe. They have been known in Europe to form masses four 
or five inches wide and ten or twelve feet long. Thename ‘‘Army Worm” is applied to ° 
them in Europe, but although it is an appropriate title, it is applied to an entirely 
different insect in this country. Here they are ordinarily called ‘‘Snake-worms” 
and the masses which they form are conversely called ‘‘ Worm-snakes.” * * *— 
[January 22, 1891.] 
Abundance of the Clover Mite in Michigan. 
* * * The Clover Mite is fairly swarming in the lower stories of our college 
building. In the chemical laboratory, which is in the basement, they seem to feed 
on a mold that gathers on the window sashes. They also breed in great numbers, and 
we find them in all stages of development.—[Charles A. Davis, Michigan. 
Urine recommended for Hel-worms. 
We have received from one of our correspondents a communication in which he 
claims to have used human urine with marked beneficial effects upon peach trees 
affected with Anguillula. He claims that a few applications of the urine to trees 
badly diseased effected a permanent cure. What do you think of it? Admitting 
the truth of the statement, what are the elements of urine that had the beneficial 
effect? If that element could be determined by analysis and experiment, would it 
not be possible to incorporate it in a fertilizer, which would act in the dual capacity 
of manure and insecticide? * * *—[S. Weller Johnston, Florida, June 11, 1891. 
Rerty.— * * * Ishould not accept the statement of your correspondent as to 
the effect of urine upon peach trees affected with Anguillulidz without the most care- 
ful corroborative tests. So many of these recommendations come to me that it is 
absolutely impossible to try them all, and it will be well for you to advise with some 
one on the ground who has facilities to experiment. We should say that the active 
destructive principle would be the uric acid, in case it turns out that the gentleman 
is correct.—[June 18, 1891. ] 
GENERAL NOTES. 
VEDALIA AND ICERYA IN NEW ZEALAND. 
We have elsewhere in these pages referred to the curious see-saw 
game which Vedalia and Icerya have been playing for some time in 
parts of New Zealand, but the following presentation of the case is so 
interesting that we reprint it from the columns of the Garden and Field 
(Adelaide, South Australia) of last June. It is written by our corre- 
‘spondent, Mr. R. Allan Wight, of Auckland. 
Sirk: It may interest some of your readers to hear news of your native ladybird, 
Vedalia cardinalis, which has done such good service of late years both in New Zea- 
land and California, against Icerya purchasi. It will be remembered that the bee- 
tle, although native to Australia, has never been any other than an inconspicuous 
