p-Aminoazobenzene hydrochloride as an insecticide

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Title:
p-Aminoazobenzene hydrochloride as an insecticide
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Book
Creator:
Phillips, Arthur M., 1903-
United States -- Bureau of Entomology and Plant Quarantine
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U.S. Department of Agriculture, Bureau of Entomology and Plant Quarantine ( Washington, D.C )
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oclc - 779487624
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E-550 mSeptember 1941
U. S.










were~~~~~~~~~ me t o e in a r c n a e t b ian 0n a l r ( ) a a
\ DEFKRTMENT
OF
AGRICULTURE
BUREAU OF
ENTOMOLOGY AND
r rLANT QUARANTINE



p-AMINOAZOBENZENE HYDROCHLORIDE AS AN INSECTICIDE

By A. M. Phillips, M. C. Swingle, J. B. eahan, and E. R. McGovran,




While making toxicological studies on a large number of organic
compounds (5), the authors found that -aminoazobenzene hydrochloride
(C1H1NsHC1) was toxic to certain insects. This material is closely re-
lated chemically to other azo compounds having insecticidal value that
were mentioned in a recent patent by Vivian and haller (6). Para-
aminoazobenzene (p-phenylazoaniline) was found effective against mosquito
larvae by Fink et al. (2) but was found ineffective against screwworms by
-Bushland (1).

Para-aminoazobenzene hydrochloride is a crystalline solid with
a purplish-brown color which may vary considerably with the purity or
physical state of the sample. It is slightly soluble in water and in acetone
and moderately soluble in alcohol. When properly prepared the compound can
be applied to foliage either as a dust or as a spray. Although the com-
pound is difficult to suspend in water, a satisfactory spray suspension
can be made with certain agents. Para-aminoazobenzene hydrochloride is
commercially available, but at present it is too expensive/ for practical
use as an insecticide. However, if it is found to be an effective insecti-
cide under practical conditions, the cost possibly could be reduced to com-
pete with the insecticides that are now available.

In common with other azo compounds, p-aminoazobenzene hydrochloride
is highly colored and will stain the skin or clothing. Spray deposits
are readily visible on foliage but have no special resistance to weathering
because of this staining quality.



I/ Approximately $1.75 per pound in small lots in 1940.





-2-


Insects Tested

Preliminary tests were made on the following species of insects:

Insect Foliage,


American cockroach (Periplaneta americana (L.))
Cabbage aphid (Brevicoryne brassicae (L.))
Cabbage looper (Autcgrapha brassicae (Riley))
Colorado potato beetle (Leptinotarsa decemlineata (Say))
Cowpea weevil (Callosobruchus maculatus (F.))
Cross-striped cabbage worm (Evergestis rimosalis (Guen.))
Fall webworm (ftphantria cunea (Drury))
Hawaiian beet webworm (Pmenia fascialis (Cram.))
Imported cabbage worm (Pieris rapae L.)
Melonworm (Diaphania hyalinata (L.))
Rice wee il 'S tcphilus orzza (L.))
Southern armyworm (Prcdenia eridania (Cram.))
Southern beet webworm (Pachyzancla bipunctalis (F.))
Termites (Reticulitermes sp.)
Yellow woolly bear (sicrsa x'rniga (F.))


None
Collards
Do.
Potato
None
Collards
Pecan
Swiss chard
Collards
Pumpkin
Wheat (seeds)
Collards
Swiss chard
None
Collards


All the leaf-feeding insects, as well as the cockroach, the rice
weevil, and the cowpea weevil, were reared in the laboratory by the methods
described in a previous paper (3). The termites were collected in the field
and brought into the laboratory for testing. The cabbage aphid was tested
as a natural infestation on collard plants in the garden.

Preliminary Tests

Preliminary tests of dusted foliage were made to determine the fact
of toxicity and the species against which the compound was effective. For
the tests on the leaf-feeding insects a settling dust chamber (4) was used
to apply the compound to excised leaves. The dusted leaves were then placed
in Petri dishes in which approximately 25 nearly full grown larvae were con-
fined. After 48 and 72 hours examinations were made for mortality of the in-
sects and an estimate of the feeding. Parallel tests were made with leaves
dusted with the standard insecticide for the respective species. The derris
sample used contained 4.5 percent of rotenone.

The results, which are given in table 1, show p-aminoazobenzene hydro-
chloride to be effective against most of the insects and in some cases as
effective as the standard insecticide. Only the cabbage looper and the fall
webvorm were unaffected by this compound. It showed considerable repellent
action to most of the insects but usually did not kill so rapidly as did the
standard insecticide.

In the preliminary tests this compound was not effective against
termites, roaches, the rice weevil, the cowpea weevil, and the cabbage
aphid; consequently no further tests were made with these species.






-3-


Table l.--Toxicity
insecticide when
species confined


of R-aminoazobenzene hydrochloride as compared with a standard
dusted on foliage and fed to nearly full grown larvae of several
in Petri dishes


Deposit Feeding on
third day
Micrograms
per sq.cm.


hydrochloride
-___-Kill in_
2 days 3 days
Percent Percent


Standard insecticide
Deposit Feeding on Kill in-
third day 2 days 3 days
Micrograms Percent Percent
per sq.cm.


Cabbage looper

Colorado potato
beetle

Cross-striped
cabbage worm




Hawaiian beet
webworm




Imported
cabbage worm


Melonworm


Fall webworm

Southern
armyworm




Southern'beet
welwbrm


Yellow woolly
bear


240

230



55
100
155
197

52
101
154
200

55
100
155
200

54
100
154
200

230

55
100
153
200

52
102
155
200

490


110

110



55
100
152
197

52
101
152
200

55
100
155
200


Moderate

None



Moderate
do.
do.
Trace

Moderate
Trace
do.
do.

Normal
do.
Moderate
do.

do.
do.
Trace
do.

Trace

Moderate
Trace
do.
do.

Moderate
do.
Trace
do.


76 92


Derris
Trace


47 --


100


Moderate
Trace
do.
do.

Moderate
Trace
do.
do.

do.
do.
do.
do.


54 do.
100 do.
152 do,
201 do.
Lead arsenate
80 Normal


53
98
155
195

50
93
155
198

185


Moderate
Trace
do.
do.

Moderate
Trace
do.
do.


96 100


STAE PARY


Insect


96
96
94
96

81
89
92
93

97
95
96
100


95
99
99
100

55
71
62
73




-4-


Fumigation Tests in Petri Dishes

Since with certain species the preliminary tests showed a high mor-
tality with only a trace of feeding, tests were subsequently made to de-
termine if this mortality was due to a fumigating action of the compound.
Lcaf sections with approximately 25 larvae each were placed in Petri dishes,
.nd about 0.5 gram of the compound between two pieces of filter paper was
pressed into the top of each dish to prevent the insects from coming in con-
tact with it. As no fumigating action occurred within 48 hours, it was as-
sumed that the high mortalities in the previous tests were not caused by
fumigation.

Phytotoxicity Tests

After the toxicity of E-aminoazobenzene hydrochloride to, certain in-
sects had been established, an experimcrt was made to determine the toler-
ance of certain tender truck-crop plants to spray deposits of this com-
pound. The spray was prepared at concentraticns of 4 and 8 pounds per 100
gallons of water, and applied to bean, swiss chard, squash, collard, and
tomato plants. After 7 ea~s a second application was made, and the final
results were recorded 14 days after the first application. Five plants of
each variety were used with each concentration of -pray. The plants were
protected from showers and at night to prevent the spray residue from being
washed off.

The two applications of the 4-100 spray caused no injury to bean,
swiss chard, collard, or tomato plants in 14 cays, but caused moderate in-
jury to squash plants in 10 days. One application of the 8-100 spray caused
slight sturting of the bean plants znd curling of the leaves in 7 days,
moderate burning of swiss chard in 5 days, and moderate to severe curling and
browning of the squash lcavcs in 7 days. No injury resulted to collard
plants in 14 days at this concentration and only slight injury to some leaves
on tomato plants.

Laboratory Cage Tests

Tests were next made to determine the toxicity of p-aminoazobenzene
hydrochloride to insects when applied as a spray on potted plants. Several
methods of making a spray suspension were tried, but tle most satisfactory
spray contained saponin as a dispersing agent. A weighed portion of the
dry compound was ground in a mortar, and then small amounts of a solution of
saponin in water were added to make a paste. When the compound and saponin
were thoroughly mixed, water was added to produce the concentration desired,
as the effect on each insect was tested at 8, 4, 2, and 1 pound of insecti-
cide to 100 gallons of water. The saponin was used at the rate of 1/8 pound
per 100 gallons. This spray was satisfactory when used on collard, swiss
chard, and pumpkin plants.

For each test the spray was applied to two potted plants with a com-
pressed-air spray gun. When the leaves were drv,. 15 nearly full grown





-5-


larvae were confined with each plant in a cylindrical screen cage. With each test of
R-aminoazobenzene hydrochloride a similar test was made with a standard insecticide.
Three examinations were made at 2-day intervals for mortality of the insects and
an estimate of the feeding on the plants.

The results of these spray tests on the cross-striped cabbage worm, the
Hawaiian beet webworm, the melonworm, the southern armyworm, and the southern beet
webworm are given in table 2. Para-aminoazobenzene hydrochloride was about as ef-
fective as derris (4.5 percent rotenone) against the cross-striped cabbage worm,
slightly more effective than derris against the Hawaiian beet webworm, and about
equal to derris against the melonworm. At the 8-100 concentration it was almost as
effective as lead arsenate against the southern beet webworm and the southern army-
worm. Against the southern armyworm, however, there was a definite decrease in tho
effectiveness of p-aminoazobenzene hydrochloride at the lower concentration.



Table 2.--Toxicity of p aminoazobenzene hydrochloride as compared with a standard insecti-
cide when applied as sprays to potted plants infested with nearly full grown larvae of
several insects


Insect


Concentration
of
insecticide
Pounds per
100 gallons


Cross-striped
cabbage worm


Hawaiian beet
webworm


Melonworm




Southern
armyworm


Southern beet
webworm


p-Aminoazobenzene hydrochloride


Tests Feeding on
sixth day
Number


3 Trace
do.
Moderate
do.


Kill after-


2 days
Pot.



64
54
31
27


3 Trace
do.
Moderate
do.

2 Trace
do.
1 Moderate

3 Trace
do.
Normal
do.

4 Trace
do.
Normal
do.


Standard insecticide
Feeding on .. Kill after--


4 days 6 days sixth day 2 days 4 days 6 days


Pct. Pct.


Trace
do.
Moderate
do.

Trace
do.
do.
Moderate


1 100
96
76

91
83
2
3


Trace
do.
do.

do.
do.
do.
Modera


Pot, Pct. Pct


Derris
63
68
59
48


26
19
3
Lead arsenate
76
71
41
te 16


Trace
do.
Moderate
do.


100
100
97
97


100
100
89
52

64
63
39
21




-6 -


Field Cage Tests

Fara-aminoazobenzcne hydrochloride was also tested against the melon-
worm on garden plots of young pumpkin plants, under normal weather conditions
except that the plants were protected from showers and at night. Three
plots of three plants each were used. The first plot was sprayed with
p-aminoazobenzene hydrochloride, the second with derris, and the third was
left unsprayed as a check. The spray was used at a concentration of 8 pounds
per 100 gallons of water and applied with a compressed-air gun fitted to a
knapsack sprayer. Each plant in each plot was then infested with melonworm
larvae and confined in a cylindrical screen cage. The cages were examined
at 2-day intervals for mortality of the insects and an estimate of the feeding
on the plants.

In this test 2-aminoazobenzene hydrochloride was as effective against
the melonworm on the fourth day as was derris on the eighth day. At this
time 83 percent of the larvae were dead, and there was only a trace of feed-
in7. Slight burning was noticed on the plants on the fourth day, but it was
not severe enough to interfere with the tests.


Field-Laboratory Tests

The effect of weathering other than direct rainfall on the toxicity
of spray deposits of p-aminoazobenzene hydrochloride was determined over a
1C-Cay period on three plots of seven plants in an outdoor garden. One plot
was sprayed with an 8-100 coi.centratior of L-aminoazobenzene hydrochloride,
another with derris at the same concentration, ard a third was an unsprayed
check. When dry, six leaves were taken at random from each plot and fed to
30 nearly full grown melonworm larvae in Petri dishes in the laboratory.
Similar samples from the plots were tested at 2-day intervals for 10 daya
The results are shown in table 3.


In these tests 2-aminoazobenzene hydrochloride was more effective than
derris against the melonworm, as shown by the retarded feeding for the first
2 eays and the slightly greater toxicity. The compound was approximately
equal to derris in toxicity or the eighth and tenth days. The reduced ef-
fectiveness after the fourth day was probably due to the rapid growth of the
plants after the spray was applied, for during the 10-day period the plants
more than doubled in size, which would tend to spread the spray deposit
over twice the leaf area.










Table 3.--Results of tests with leaf samples taken at 2-day intervals from plants
sprayed in the garden with R-aminoazobenzene hydrochloride and the standard insvcti-.
cide and fed to nearly full grown larvae of the melonworm in Petri dishes


R-Aminioaz6benzene
Time hydrochloride
between Feeding _ill a-fter-
spraying after 2 days 3 days
a 'days
sampling
yPercent Percent


0
2
4
6
8
10


Trace
do.
Moderate
do.
do.
do ...


61
83
70
73
30
46


Standard insecti-
-cide (derris) Check (unsprayed)I
Feeding' Kill after-- Feeding Kill Iter-
after 2 days 3 days after* *2 days 3 days
3 days 3 days


Percent Percent -


Moderate
do.
do.
do.
do.
do.


30
60
56
10
23
46


- 11Percent Percent


Normal
do.
do.
do.
do.
do.


Summary .-

In 'laboratory tests p,-aminoazobenzene hydrochloride, a commercially
available organic compound, was found to be toxic' to a number of insect
pests. In preliminary tests on 15 species gQod results were.obtained against
all. but 2. species, although it did'not usually kill so rapidly as did the
standard-insecticides. No fumigating action was shown in *Ve:sts with this
compound.

In laboratory cage tests where the compound was applied as a spray
to potted plants, the results with certain species were similar to those
obtained in Petri-dish tests. In field cage tests p-aminoazobcnzene hydro-
chloride was as effective against the melonworm on the fourth day as was
derris on the eighth day. In the field-laboratory test also it was more
effective than derris, both materials being considerably less effective
after 10 days of weathering than on the date of application.

A 4-100 spray did not injure any of the tender truck-crop plants
used in the tests except squash, but an 8-100 spray caused some injury to
most of the plants used.

The compound was not toxic to termites, the American cockroach, the
rice weevil, the cowpea weevil, and the cabbage aphid in preliminary tests.





-8-


UNIVERSITY OF FLORIDA
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3 1262 09230 4012


Literature Cited

(1) Bushland, Raymond C.
1940. The toxicity of some organic compounds to young-screw-
worms. Jour. Econ. Ent. 33: 669-76.

(2) Fink, D. E., Smith, L. E., Vivian, D. L., and Claborn, H. V.
1938. Toxicity tests with synthetic organic compounds against
culicine mosquito larvae. Bur. Ent. and P1. Quar.
Cir. E-425, mimeographed.

(3) Swingle, M. C., Gahan, J. B., and Phillips, A. M.
1941. Laboratory rearing of certain leaf-eating insects. Jour.
Econ. Ent. 34: 90-95, illus.

(4) Swingle, M. C., Phillips, A. M., and Gahan, J. B.
1941. Laboratory testing of natural and synthetic organic
substances as insecticides. Jour. Econ. Ent. 34: 95-
99, illus.


(5) Gahan, J. B., and Phillips, A. M.
1941. Phthalonitrile as an insecticide.
Quar. Cir. E- 548, mimeographed.


Bur. Ent. and P1.


(6) Vivian, D. L., and Haller, H. L. J.
1938. Insecticide. U. S. Patent 2,111,879, issued March 22.