REPORT OF H. G. HUBBARD. 
[15] 
(<) Oue entirely fluoroscopic fragment applied to hack of neck: affected in H min- 
atee ; oonmlsed in 3 minutes ; 4.30 p. m., appears recovering. (August 12, 
larva died this morning). 
(A.) One entirely microscopic fragment applied underneath anterior segments be- 
tween legs: Adhered only a few seconds; appears affected after 15 minutes, 
but able to move about. 4.30 p. in., recovering and eating; later, fully recov- 
ered. (August 13, alive and well.) 
Xote. — Larva? (/) (at) and («) were treated as follows : A small quantity of pyre- 
t brum phu - d on a piece of paper was lightly sprayed with an atomizer, and 
allowed to remain covered \\ ith drops of moisture for about 10 minutes. The 
lame were then touched with a needle dipped in this poisoned dew. 
(/) A single, very slight, and probably insufficient application beneath anterior seg- 
ments : no moisture adhered to larva : affected after 1 minute 15 seconds ; 1 
hour later, appears torpid but not convulsed. 4 p. m., recovered and eating. 
(August 18, alive and well.) 
■ Toaoned with poisoned dew about anterior segments, and moisture left upon 
the back of tin- segments: more thoroughly applied than in preceding larva ; 
affected in 45 seconds; convulsed in 8 minutes. 4.30 p. m., recovered. (Au- 
■_;ii-f 1 '2, alive and well.) 
/* | A very young larva, probably hatched late this morning, was allowed to crawl 
along needle and over a drop of poisoned dew : instantly affected; convulsed 
in l."> seconds. Died in p. in. 
,//') Second experiment with larva (<j) made in p. m. One fragment, size of blowfly 
egg, laid on back, middle of body, not touching the skin, but adhering to hairs; 
dropped off in 30 seconds: evidently affected in 45seconds; completely con- 
vulsed in 2 minutes. Died in a few hours. 
Pyrethrum powder was blown with a bellows upon Aletia moths clustering upon 
ripe figs at night. The moths wereevidentlv affected, but Hew away in a few minutes. 
No fresh moths alighted upon fruit thus dusted, but M thepowdex rapidly loses its 
Strength when exposed to the air, the protect ion afforded by it to fruit probably lasts 
only a few hours, and it cannot therefore be recommended for this purpose. 
Tried upon different insects, if appears to affect the higher Hymenoptera more than 
other insects. Antsaie almost in>tantl\ affected. Wasps continue feeding for about 
twenty seconds, and are violently affected in from one to t wo minutes. Larva? of all 
kinds are more quickly affected than imagos. Termites, owing probably to their 
tender bodies, are instantly a Dec ted and soon killed. Spiders resist longer than 
anything el 8e. They sometimes change t heir skins when dusted with the powder. 
i opris and I'hanccuH are slightly affected, and long resist the action of the powder. 
S<olopc)idri(1<r aDectcd similarly to spiders. Bugs slightly affected, especially the 
largo and heavily arined predaceous species. Large grasshoppers slightly affected. 
Roaches very violently a Dec ted. These observations refer to the immediate action 
of the dry and undiluted powder, and are comparative only. There is no doubt that 
insects often recover from slight applications. 
Experiments in the field, with the dry powder sifted upon the plants, gave very un- 
satisfactory roults, unless large quantities of the powder were used. On Augusts, 
a very w indy day, I tried an application w ith the bellows, allowing the wind to carry 
the powder in line clouds through the foliage, and using about one pound to the acre. 
In this way, owing partly to the impossibility of securing an equal distribution, 
some worms wereaOeoted :it a distance of ten or tifteen feet, while others, much nearer, 
were not affected at all. I have reason to believe that very few worms were killed 
outright at this trial. Some recovered in a few hours. A number of those which 
showed signs of pain, but had been very lightly dusted, I conlined in vivaria, and all 
complete ; l their transformation in the usual time. At the time the foregoing experi- 
ment w as made, t he leaves were quite wet with recent rain, and another heavy shower 
occurred later in the day. 
Infusions made by pouring hot (not boiling 1 ) water upon the powder were found in- 
effective and quite worthless. 
With a strong extract I have had no opportunity of experimenting. Alcohol poured 
upon the powder, extracts a suDieient quantity of the poisonous oil to be very effective 
when used with an atoini/.er, but is too expensive for use on a large scale. 
London purple. — Several experiments were tried in which small quantities of this 
powder were dusted upon the plants without diluents. Whenever a quantity was 
used sufficient to kill the worms the leaves were badly scorched. 
J'<>i«onin!i the moths. — At a time when the moths swarmed at night about the fallen 
fruit under persimmon trees in the fields, I poisoned the fruit with London purple, and 
also with white arsenic. In this way many moths were undoubtedly killed, but as 
numbers of them Dew away to die, the exact proportion could not be ascertained. 
Under nettings covering cotton plants, moths were readily killed by giving them poi- 
soned fruit. They do not appear to dislike the fruit even when mixed with an excess 
of London purple or arsenic, and settle quite as readily upon the poisoned as upon 
