INSECTS. 
79 
true cotton-caterpillar, which is believed to confine itself to the cotton- 
plant alone. . . . 
The grass-worm cannot he classed among those insects very inju- 
rious to cotton, although instances have been known where it has 
destroyed the foliage to some extent. It is more especially mentioned 
here as being found in cotton-fields, and often confounded with th e 
true cotton-caterpillar. The difference, however, is more plainly 
described under the head of the latter. 
The same remedies are applicable to this insect as have been sug- 
gested for the boll-worm caterpillar, or any other night-flying moth. 
THE RED SPIDER. 
( Acarus ?) 
Much injury is done to the cotton-leaf by a minute red spider, 
(PI. VI. fig. 7,) which presents very much the appearance of inci- 
pient r ust,° except that the leaf is of a more rusty-brown in spots, 
instead of the bright-yellow of the real rust. This red spider prin- 
cipally attacks the under side of the leaf, the spots caused by its 
punctures turning brown, and finally increasing until it is completely 
stung all over, and falls from the plant. 
This insect is extremely minute, and when on the leaf, it can 
scarcely be discerned by the naked eye. Some of the young appear 
to be of a greenish cast; but, when theyare advanced in age, the 
abdomen assumes a dark crimson shade, with darker maroon spots 
upon its upper surface. The legs, which are hairy, are eight in 
number. ... . . .... 
This family of the mites (acan) do much injury to vegetable life, 
as they are so extremely minute as to escape the notice of the super- 
ficial observer. When they infest grape-houses, or rose-bushes, 
it has been recommended to dust the leaves while moist with flour of 
sulphur. 
THE DROP OR HANG-WORM. 
( CEceticus ?) 
The “drop-worm,” as it is commonly called, (PI. VI. fig. 8,) 
is occasionally found upon the cotton-leaf, but generally infests the 
arbor-vitie, larch, and hemlock-spruce. It is also found upon many 
of the deciduous-leaved trees, such as the linden, negundo, and 
maple. Dr. Harris states that the female worm never quits her case, 
but lays her eggs in the skin of the chrysalis, in which she herself 
also remains until the eggs are all deposited, when she closes the end 
with down, and crawls out of the case and dies. These eggs being 
hatched the young worms, after they are hatched, make little silken 
cocoons,’ open at both ends, and are covered with fragments of leaves, 
twio-s &c., in which they conceal themselves, and drag them about 
wherever they move. These cases are enlarged as the insects increase 
in size, and are still carried about by the worms. When they change 
