[14J REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
I believe also that a broad glare, like that of a bonfire, attracts a greater number 
than the concentrated light of a lantern. I have also known them to fly at the glow- 
ing end of a cigar. 
That the moths are exceedingly fond of fruit, is a fact too well known to require 
iteration. I found them clustering upon figs, peaches, and especially upon persimmons, 
which attract them from great distances. 
# * * * * * * 
EXPERIMENTS WITH POISONS. 
Pyrethrum. — Samples of the powder sent me by the Commission were of two sorts, 
Milco's Californian Buhach and an imported product. To test their relative strength, 
sixty Cotton Worms were collected and divided into two lots, as equally as possible, so 
that neither set should contain an undue proportion of old or of young worms. Each 
set was placed in a Mason jar, and thoroughly dusted with a small quantity of 
powder, one jar with the Buhach, the other with the imported pyrethrum. The 
worms were immediately afterwards turned out upon newspapers spread upon the 
ground. Those dusted with Bnhach were paralyzed and unable to crawl about in 
from 15 to 20 minutes. Those treated with imported pyrethrum were similarly 
affected in from 25 to 30 miuutes. In both lots the worms began to be affected in less 
than one minute, and nearly all died within 12 hours. Another experiment was made 
upon one hundred worms of all sizes, in which the x>owder (imported) was applied in 
the open air by means of a bellows. Worms one-fifth to one-third grown were com- 
pletely paralyzed* in 10 minutes; worms one-half grown in 30 to 45 minutes; full- 
grown worms showed the full effect of the poison after several hours. In about three 
hours the smaller worms appeared to be dead. The oldest worms did not die before 
night. Experiments were made in the field upon Aletia larvae, using very small 
quantities of pyrethrum powder. A few particles dropped with the fingers upon 
worms from half to full grown produced convulsions in from 3 to 10 minutes. The 
action of the poison is much more powerful upon young than upon old worms, but 
depends in each case less upon the amount of powder used than upon the part of the 
body it first touches or the method of applying it. Very small particles placed upon 
the -sides of the larvae, especially near the anterior spiracles, produce a more marked 
effect than larger quantities dropped upon their backs or lodged among the hairs. 
The effect is also enhanced by driving the powder with force against them, by means 
of a bellows, for example, as the particles are thus driven into closer contact. The 
effect of Californian Buhach (pyrethrum) powder upon young Aletia larvae is shown 
in the following experiments, the object being to ascertain the minimum quantity 
that could be used with effect : 
All the larvae were hatched last night (August 10), from eggs laid in breeding jar dur- 
ing the night of August 7 (except larva [?<]> which was only a few hours from the 
«gg). 
(a) Three minute fragments of pyrethrum laid upon back (terminal half of 
body) with the point of a needle : larva affected in 15 seconds ; convulsed in 1 
minute and 15 seconds. Died in p. m. 
(b) One miuute fragment applied on back (anterior segments) : fragment dropped 
off in 3 minutes; probably only adhered to hairs of body 3£ minutes; larva 
appeared affected but slightly ; after three hours larva appears to have re- 
covered. P. m., went to eating and fully recovered. This is a very vigorous 
larva, probably several hours older than the rest. (August 12th ; has grown 
larger, and eating well. ) 
<c) One almost microscopic fragment applied, with needle point, to side near 
spiracles: evidently affected in 15 seconds; convulsed in 1£ minutes. Frag- 
ment adhered one minute. Larva died in p. m. 
(d) One very minute fragment (almost microscopic fragment) applied on side of 
body near middle. Larva lost sight of during 4 minutes, at end of which 
time was entirely convulsed. Died in p. m. 
(e) Several (3 or 4) small fragments applied on side of body : affected in 30 seconds ; 
convulsed after 2 minutes 15 seconds. Died in p. m. 
(/) One minute fragment on middle of back : affected in 1 minute 15 seconds; con- 
vulsed in 3 minutes; fragment dropped off in 3 minutes. Four o'clock p. m., 
larva recovering; later, went to eating; entirely restored. (Aug. 12, alive and 
well.) 
{g) One microscopic fragment on back at anal extremity of body and very soon 
lost off (20 seconds ?). Seemed affected after 5 minutes ; examined after 2 
hours, seems not iujured. In p. m., entirely well [see (#')]• 
(/<) One large fragment (size of " blowfly " egg) applied for 5 or 6 seconds to side of 
body, near or upon spiracles: affected in 2 minutes; convulsed in 4 minutes; 
2 hours, unable to move about; 4.30 p. m., still alive but disabled. Died be 
fore night. 
