RELATIVE EFFECT OF PYRETHRUM ON DIFFERENT INSECTS. 179 
is preferable on that score alone; and in the future it can hardly fail also to be the 
cheaper of the two. This is the more likely, as the tea made of the leaves and stems 
ha§ similar, although considerably weaker, effects; and if the farmer or fruit-grower 
were to grow the plants, he would nave all the expense of harvesting and grinding 
the flower-heads by simply using the header, curing the upper stems, leaves, and 
flower-heads all together, as he would hops, making the tea of this material by the 
hogshead, and distributing it from a cart through a syringe. It should be diligently 
kept in mind that the least amount of boiling will seriously injure the strength of 
this tea, which should be made with briskly boiling water, but then simply covered 
over closely, so as to allow of as little evaporation as possible. The details of its 
most economical and effectual use on the large scale remains, of course, to be worked 
out by practice. 
Having 110 sufficient supply of flower-heads at our disposal we Lave 
been unable so far to repeat these experiments. Mr. Hubbard made 
an infusion by pouring hot, not boiling water upon the powder, but 
found it ineffective and quite worthless, and we have had similar re 
suits with the decoction of the powder. 
The wet application of Pyrethrum, in whatever form it may finally 
prove most convenient, is unquestionably superior to its application 
in powder form, the former being by far more economical and, with the 
improved appliances, enabling us the better to reach all the worms. 
Effect of pyretiieum upon other insects. — While arsenical 
poisons directly 53 affect only those insects which feed on the leaves of* 
the cotton plant, or, in other words, only the enemies of the plant, IV 
rethruui affects all insects that happen to be on the plants at the time 
of the application. Since among these are gn at numbers of some of 
the most efficient enemies of the worm, it is not without interest to 
record here such observations as have been made incidentally in regard 
to the effect of Pyrethrum on other insects besides Aletia, even if they 
include some that have no connection with the cotton plant. Mr. Hub- 
bard reports as follows: 
Tried upou different insects, pyrethruin appears to affect the higher Uymenoptvra 
more than other insects. Ants are almost instantly affected. Wasps continue feed- 
lag for about '20 seconds, and are violently affected in from 1 to 2 minutes. Larva* of 
all kinds are more quickly affected than imagos. Termites, owing probably to their 
tender bodies, are instantly affected aud soon killed. Spiders resist longer than any- 
thing else. They sometimes change their skins when d list «'il witli the powder. Copria 
and FktUUBU* are slightly affected aud long resist the action of the powder. Scolo- 
pendridce. affected similarly to spiders. Bugs slightly affected, especially the large 
and heavily armed predaceous species. Roaches very violently affected. These ob- 
servations refer to the immediate action of the dry and undiluted powder, and are 
comparative only. 
Mr. Schwarz records the following observations on this point : 
A thorough application of my alcoholic extract (10 drams to 2 gallons of water), 
and of my pyrethrum-water ('200 grains of powder to 2 gallons of water), affected other 
insects as follows : They had no visible effect on all spiders, without exception, on 
the larvae of Lagoa sp., Hyperchiria io, Acronycta obliirita, and Bcpantheria Bcribonia \ 
they affected, but not fatally, the common Black Cricket, the various species of grass- 
hoppers and their larvae, the ground-beetles so common under the fallen leaves at 
the base of the plants (Anisodactylm rusticus, Platynus puncti/ormis and P. maculicollits), 
