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Un1ft 't'teu departmentt of Agriculture
Agricultural Research Administration
Bureau of Intomology and Plant Quarantine
NICOTInI INSICTICIDIS. PART III-IDUST CARRIZRS FOR NICOTINE
By 1. L. Mayer, Division of Control Investigations, Bureau of
Entomology and Plant Quarantine, and Florence B. Talley
and C. V. Woodward, eastern Regional Research Laboratory,
Bureau of Agricultural and Industrial Chemistry /
This is the third of a series of investigations on nicotine
insecticides conducted by this Bureau in cooperation with the
Bureau of Agricultural and Industrial Chemistry. Part I of this
series (S-646 issued in 1945) reported a study of complex salts
containing nicotine, usually combined with a metal, and Part II
(1-709 issued in 1946) described tests with a large number of mate-
rials to find activators for nicotine. The purpose of the present
study was to determine the effect of various carriers on the tox-
icity of dusts or sprays containing nicotine sulfate.
As before, the materials tested were prepared at the Eastern
Regional Research Laboratory of the Bureau of Agricultural and
Industrial Chemistry, for testing against plnut-feeding insects by
the Bureau of Entomology and Plant Quarantine et its Sanford, Yia.,
Previous investigations by Headlee and Rudolfs (e, 4) and by
Thatcher and Streeter (j) have shown that there are three types of
dust carriers for nicotine or nicotine sulfate: (1) 'Adsorbent'
carriers, which tend to prevent the volatilization of nicotine:
(2) "inert* carriers, which merely expose large surface areas; and
(3) 'active' carriers, which liberate nicotine from its salts by
chemical action. Examples of these types are bentonite, pyrophyllite,
and dolomite, respectively. These early studies were concerned large-
ly with the control of aphids, and the active carriers were the most
effective of the three types. It was further shown by De Ong (3) and
Headlee and Rudolf. (3) that the toxicity of nicotine-containing dusts
and sprays was directly proportional to the rate of nicotine evolu-
I/The authors are indebted to 1. R. McGovran (transferred to
Office of Experiment Stations, November 3, 1946) and G. T. Bottger,
Division of Control Investigations, for supervision of the entomologi-
cal tests; and to J. J. Willaman, Eastern Regional Research Laboratory,
for many valuable suggestions in this investigation.
The volatilization of nicotine from dusts kas'affected by
factors other than the type of carrier. Nicotine was more readily
lost from a coarse dust than from a fine one (J. 4). In aphid con-
trol a temperature of at least 70 P. was required for satisfactory
evolution of the alkaloid. Small amounts of water hastened nicotine
evolution from the active carriers (., 7, ).
In an attempt to increase the efficiency of nicotine dusts
against several lepidopterous larvae, it was deemed advisable to in-
vestigate in a preliminary manner the effect of various carriers in
the dust mixtures. Accordingly 39 materials, selected to represent
a wide range in particle size, were obtained from commercial companies
in March 1944. Particular attention was directed to carriers that did
not release nicotine from the sulfate, inasmuch as a lasting deposit of
the toxicant appeared desirable. However, several active carriers
were included for comparison. A further objective of these comparisons
was to select a carrier which would be used as a standard in a large
number of dust mixtures employed in screening tests on nicotine deriva-
tives and in the search for nicotine synergists. Characteristics which
must be considered to appraise fully the economic usefulness of carri-
ers such as dustability, drifting, packaging requirements, availability,
and standardization were not studied in the laboratory tests. Further-
aore, no attempt was made to evaluate any possible synergistic action
of the carriers which gave the best*results.
This investigation was confined to preliminary observations of
the toxicity of the various nicotine dust mixtures to the melonwora
(Diaphania hyalinata (L.)) and the southern arayworm (Prodenia eridania
Materials and experimental Procedure
All mixtures contained 5 percent of nicotine on the alkaloid basis.
In the bentonite this was supplied by free alkaloid; in the others by
aicot ins sulfate.
fhe 37 carriers studied, plus the 2 in the standard dusts, Pyrax
ABB (pyrophyllite) (No. 38) and Volclay bentonite (No. 39), are listed
Is table 1. With the exception of Carolina pyrophyllite (No. 19),
which was approximately 20X) mesh, all dusts were 300-325 mesh or finer.
The pH of the carriers was determined by suspending 5 grams in 20
ml. of water and allowing the suspension to stand until a constant pA
value was reached. The pH of the carriers plus 5 percent of nicotine
as the sulfate was determined in a similar manner. All readiangs wre,
made with ag ;lass-electrode pH meter.
The loss of nicotine was determined by chemical analysis of the
fixtures before and after 16 hours' exposure at 70 F. In these tests
2 grams of dust mixture was uniformly distributed on a square foot of
glass area. Nicotine determinations were made by the silicotungstic
acid procedure. The percentages of nicotine lost from the dusts con-
taining 5 percent of nicotine as the sulfate are reported in table 1.
Most of the dusts were tested against the first-instar southern
armyworm and the fourth-instar melonworm. The pulverized limestone
mixture, which was not of a dustable consistency, was restricted to
The testing procedure used was similar to that described by
Single (8) and in Part I of this series. About 30 larvae were used
in each test. The large larvae were placed on previously dusted
pumpkin-leaf sections in 9-cm. petri dishes and the small larvae in
cloth-covered vials on dusted collard-leaf sections. Counts were
taken at the end of the first, second, and third days. The test was
terminated on the third day.
A nicotine sulfate dust (nicotine 5 percent) in pyrophyllite
(Pyrax ABB) was used as the standard of comparison. Some of the mix-
tures that gave a higher mortality than the standard were tested in
sprays and subsequently compared with nicotine bentonite. This work
was not completed, however, because the entomological laboratory was
transferred from Sanford, Fla., to Anaheim, Calif., where the melon-
worm and the southern arayworn were not available.
Discussion of Results
Of the 37 materials tested as carriers for nicotine, 9 gave an
increase in toxicity of more than 15 percent over the standard in at
least one test (table 2).
When compared with the Pyrax ABB (pyrephyllite) standard, the
nicotine dusts that showed the highest mortalities of the southern
armywora were those containing magnesia talc, fuller' s earth 2 90-44B,
talc No. 21, talc No. 23, fuller's earth I 90-44A, and fire clay.
Against the melonworm the most effective carriers were Gruadite Boed,
magnesia talc, and Cherokee clay. fuller's earths I 90-44A and
Z 90-44B were slightly above the standard in tests on melonworm. When
used in spray% pulverized limestone, fuller's earth 1 90-44A, magnesia
talc, Grundite Bond, and fuller's earth 3 90-44B gave better results
than the standard against the southern arayvorm, and magnesia talc
gave the best results against the melonworm.
Of the carriers compared with bentonite, fire clay was the only
material that showed up as possibly better, both in a dust and in a
spray, against the melonworm. Grundite Bond was somewhat betL- in
a dust against the melonwora, while fuller' s earth 2 90-44A a Lt ;er
in a spray against the southern armyworm. All other materiis 'r-
inferior to bentonite in most tests. It should be noted that n h
bentonite series nicotine sulfate is compared with what is :- .
considered to be a reaction product, namely, nicotine bentonite
Both acid and alkaline materials are represented in the t of
9 best duet carriers, The clays are essentially acid; the pc. of re
clay is 4, of Cherokee clay 6.1, and of Grundite Bond 5,97. .ca
and limestone are alkaline; talc No. 21 has a pH of 8.5, talc ?
of 8.55, magnesia talc of 8.95, and pulverized limestone of 8-. The
fuller' s earths, Z 90-44A and Z 90-443, are somewhat less alk,. e
than the talcs, having pH values of 7.8 and 8.02, respectiir;l:r. It
is believed that the increased kills of the southern armyworn. -
some of these alkaline materials, especially limestone, may v" ,
due to nicotine fumigation, as the cloth-covered vials in whi. .
tests were carried out do not afford much ventilation.
Of the 9 best dusts only 2 showed any great loss of nicot' .ur-
ing the 16-hour period of exposure. Pulverized limestone lost :er-
cent of its nicotine, which was expected on the basis of pre- .. find-
ings. Talc No. 23 lost 27 percent and talc No. 21 lost 17 pei-.ct
The other 6 dusts lost onl 1 to 9 percent of nicotine.
It is recognized that the physical characteristics of tL .. -t
may have influenced their effectiveness. The addition of enou-V nico-
tine sulfate to give a dust containing 5 percent of nicotine in many
cases resulted in a poorly dustable mixture with impaired effici-.
In this regard special mention should be made of the u-iic-,-
physical properties of fuller's earth 1 90-443, mineralogical- 1: ,?
as attapulgite. It is a very light, fluffy material with a r.,-Lable
power to absorb liquids. As much as 33 percent of mineral oil L--:
been incorporated in this material without impairing its excellent
dusting qualities. On the basis of these preliminary data we .c.Atsd
that attapulgite be considered as a carrier for insecticides. 2,
Thirty-seven materials were tested as carriers for nicot :- -
fate against the melonworm (Di&phania hyalinata (L.)) and the `-"- :2n
armyworm (Prodenia erdani (Oram.)). Nine materials appear, cl
?/Since this manuscript was submitted, attapulgite has for- a -
tensive commercial use as an insecticide carrier.
produce higher kills than the pyrophyllite standard in at least one
test. Three of then, magnesia talc and fuller' s earths 3 90-44A and
I 90-443, gave considerably higher kills against both insects in both
dusts and sprays.
Of the limited group compared with the bentonite standard, fire
clay vas as good or better, both in dusts and sprays, against the
melonvora. Fuller's earth A 90-44A vas better in dusts against the
aelonvorm, and fuller' s earth 3 90-44B was better in prays against
the southern arayworm.
The two standards were compared with each other in only one spray
test, and in this case bentonite was better than the pyrophyllite
(Pyrax ABB) against the armyvora.
Insect mortality appeared to have no veil-defined relation to
pH or to nicotine volatility, since acid and alkaline materials were
represented aaonc the 9 best materials, vhile only 2 of them shoved
appreciable nicotine loss.
Juller's earth 3 90-44B, or attapulgite, is considered the best
of the new materials tested because of its unique ability to absorb
large quantities of liquid, either oil or water, and. because of the
high aortalities resulting from its use.
Table 1.-pH values and nicotine retentiveness of dusets used as carriers.
:: pH : pH of carrier : Nicotein lost
Carrier Supplier j/ : found : $ 5 percent : after 16 hours'
,!, B of nicgtie 0. A engura
2 Harmon clay
3 Peerless clay
4 Fillsore clay
5 Fire clay
6 Perry clay
9 Topton clay
12 Walnut shell
13 Talc No. 21
14 Talc No. 23
United Clay Mines,
Trenton, N. J.
R. T. Vanderbilt Co.,
230 Park Ave.,
New York, N. Y.
United Clay Mines
Illinois Clay Products
Co., Joliet, Ill.
United Clay Mines
R. T. Vanderbilt Co.
United Clay Mines
J. J. Huber, Inc.,
460 V. 34th St.,
New York, N. Y.
National Gypsum Co.,
4668 N. Teutonia Ave.,
I. N. Richards Co.,
1203 E. State St.,
Trenton, N. J.
Eastern Magnesia Talc
Co., Burlington, Vt.
orc4.4 5 14t
4*4 5 14
: : pR : pH of carrier : Nicotine lost
Carrier Supplier J/ : found. : / 5 percent :after 16 hours'
I .of nicotine : exIogre
15 Fibrous talc
18 Micro Velva A
21 Puller's earth
22 Fuller's earth
24 Frianite M3X
25 Frianite DS
Loomis Talc Co.,
Gouverneur, N. T.
Carbola Chemical Co.,
Natural Bridge, N. Y,.
Co., 10 3. 40th St.,
Nev York, N. T.
Illinois Clay Products
Attapulgus Clay Co.,
Butcher and Co.,
Los Angeles, Oalif.
Vyodak Cheaical Co.,
4600 X. 71st St..
American Colloid. Co.,
362 V. Superior St.,
rE : pH of carrier
Found : / 5 percent
1.... ; of nicotine
t Nicotine lost
:after 16 hours
29 Silene BF
Pitt ,. .& ite .... -i
< o ;, o l .aiL> ,.l- .-..
Plasa, lew Tcri-;
( Fly A oL)
32 No. 2261
35 China clay
38 Pyrax ABB
,.uth e e ti i I ..
Ph! ,de]r.' i, >. Pa%
.. reni Co ,
.. I~r n Pe.t
Corson Lime Co.,
R. T. Vpcdrbilt Co.
Wagner and Co.
.i/The address of each supplier is given uonly cce in this tpble.
I J /
O 1 I I
1 I I 0
10 I. I
I I I CQ
I I WCQ
to. -I t ,- to
I I I
S I I I 0
I I I I I ,-I
Table 3.--Materials comparable to or poorer than the standard in
S Southern Melon-
Carrier armyvora worm
1 Colloidal kaolin +/ -
2 Harmon clay *+ -
3 Peerless clay +
4 Fillmore clay + -
6 Perry clay + -
8 Bancroft clay -
9 Topton clay -
10 Chicora clay -
11 Gypsuma + -
12 Walnut shell flour -
15 Fibrous talc (Loomkill) -
17 Velvet filler R -
18 Micro Velva A +
19 Carolina pyrophyllite + +
23 Bauxite E 90-44C -
24 Frianite M3X -
25 Frianite DS -
26 Wyobond bentonite +
27 Volclay bentonite (Hivo) -
28 Volclay bentonite (Visclo) -
29 Silene BF +
30 Micronized Pyrax ABB
31 Ferasil ( Fly Ash) -
32 No. 2261 Florida land pebble -
33 Diluex -
34 Florigel -
35 China clay -
37 Magnesite -
i/ + Slightly better than standard; poorer than standard.
(1) De One, 2. Re
1923. The relation between the volatility and toxicity of
nicotine in sprays and dusts. Jour. lcon. Bat.
1943o Prianite, an insecticide diluent. Jour, Icon. Bunt.
(3) Readlee., To J., and Rudolfs, WeV.
1923. Some principles which underlie the making and use
of nicotine dxist. N. J. AMr. Expt. Sta. Bul. 381,
(4) ________ and Rudolfsa, W.
1924, Some further facts relative to the principles under.
lying the making and use of nicotine dust. No J.
Ar. lEpt. Sta. Bul. 400, 44 pp.
(s) Smith, C. 1.
1934. Base exchange reactions of bentonite and salts of
organic bases. Amer. Chem. Soc. Jour. 56) 1561-1563.
1937. Compound and process for making nicotine-bentonite
compounds. (U. S. Patent No. 2,096.566) U, S. Patent
Office, Off. Gas. 483s 649.
(7) Streeter, L. Re
1925. Influence of temperature and humidity upon the vola-
tilization of nicotine from tobacco dust-lime hydrate
mixtures. Jour. Econ. Int. 18: 590-593.
(8) Sviagle, M. C.
1943. Exploring the insecticidal possibilities of new mate-
rials. In Laboratory procedures in studies of the
chemical control of insects, edited by F. L. Campbell
and 1. Moulton, Amer. Assoc. Adv. Sci., Pub. 20,
pp. 82-84. Vashington, D. C.
(9) Thatcher, R. V., and Streeter, L, Re
1923. fastors which affect the volatility of nicotine from
insecticide dusts. I. Y. Agr. xpt. Sta. Bul. 501,
UNIVERSITY O FLORIDA
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