SB
818
C578
ENT

b 30

Issued January 30, 1913.

U.S. DEPARTMENT @F AGRICULTURE,

BUREAU OF ENTOMOLOGY—CIRCULAR No. 166.
L. O. HOWARD, Entomologist and Chief of Bureau.

FLOUR PASTE AS A CONTROL FOR RED SPIDERS

AND

AS A SPREADER FOR CONTACT INSECTICIDES.

BY

WILLIAM B. PARKER,

Entomological Assistant.

WASHINGTON : GOVERNMENT PRINTING OFFICE ; 1913

7 113

i

feral Musevs=

Be

BUREAU OF ENTOMOLOGY.

L. O. Howard, Hntomologist and Chief of Bureau.
C. L. Maruatrr, Entomologist and Acting Chief in Absence of Cricf.
R. S. Cirrron, Hrecutive Assistant.
W. F. Taster, Chicf Clerk.

¥. H. CHITTENDEN, in ch arge of truck crop and stored product insect investigations.
A. D. HopxKInNs, in charge of forest insect investigations.

W. D. HUNTER, in charge of southern field crop insect investigations.

IF. M. WEBSTER, in charge of cereal and forage insect investigations.

A. L. QUAINTANCE, in charge of deciduous fruit insect investigations.

E. F. Puiivies, in charge of bee culture.

D. M. Rocers, in charge of preventing spread of moths, field work.

Roiia P. Curriz, in charge of editorial work.

MABEL CoLcorD, in charge of library.

TRUCK CROP AND STORED PRopUCT INSECT INVESTIGATIONS.

F. H. CHITTENDEN, in charge.

C. H. PoPENOE, WILLIAM B. PARKER, H. O. MarsH, M. M. Hicu, Frep A. JOHN-
STON, JOHN E. Grar, C. F. STann, D. E. FINK, entomological assistants.

A. B. Duckett, scientific assistant.

I. J. Conpir, collaborator in California.

W. N. Orb, collaborator in Oregon.

THoMAS H. Jones, collaborator in Porto Rico.

Marion T. VAN Horn, PAULINE M. JOHNSON, ANITA M. BALLINGER, preparators.

It

CIRCULAR No. 166. Issued January 30, 1913.

United States Department of Agriculture,

BUREAU OF ENTOMOLOGY.

L. O. HOWARD, Entomologist and Chief of Bureau.

FLOUR PASTE AS A CONTROL FOR RED SPIDERS AND
AS A SPREADER FOR CONTACT INSECTICIDES.

By WILLIAM B. PARKER,
Entomological Assistant.
RESULTS OF EXPERIMENTS.

During some spraying experiments for the control of the red spider
(Tetranychus bimaculatus Harv.) on hops in 1912 some difficulty was

Fic. 1.—Lime-sulphur mixture and flour paste (left half), showing spreading effect of
flour paste; lime-sulphur mixture straight (right half), showing beaded effect due to
lack of flour paste. (Original.)

experienced in obtaining an effective spreader for the lime-sulphur

solutions, due to the fact that soap forms a precipitate with the cal-

cium polysulphid. While testing the following combination—flow-
1

2 FLOUR PASTE AS A CONTROL FOR RED SPIDERS.

ers of sulphur 15 pounds, water 100 gallons, and flour paste (as a
“ sticker”) 4 gallons—a formula advised for red spiders in Bulletin
No. 154 by Mr. W. H. Volek of the California Experiment Station,
it was observed that the mixture spread over the leaves very readily.
The flour paste was evidently the spreader and was accordingly
mixed with the lime-sulphur solutions. The result was a smooth
mixture which spread over the foliage very readily and gave unusual
results as an arachnicide. The proper proportions were found to be
4 gallons of paste (4 pounds of flour) to 100 gallons of spray. Table
I graphically represents the relative effectiveness of the lime-sulphur
spray, with and without the flour paste, for the red spider on hops.

TABLE I.—Relative effectiveness of lime-sulphur spray, with and without flour

paste, against the red spider on hops in the Sacramento Valley of California,
in 1912.

Number | Number | Per cent
Formula. of mites | of mites | of mites
present. | killed. killed.

Lime-sulphur, 36° Baumé, 1-75; flour paste, 4-100............-....----+--- | 698 | 692 99.0
Eime-sulphur;. 36° Baume: 1-75. . 22sec ee eee se eer eee emia | 360 | , 135 37.5

From the foregoing table it is very evident that the use of flour
paste greatly increases the efficiency of the lime-sulphur spray and
that without the paste the spray was very ineffective. These results
were substantiated by other experiments and, by a check experiment
with the flour paste, 4-100, used without the lime-sulphur, it was
found that the increased efficiency was mainly due to the spreading
effect of the paste.

Having proved a most efficient, cheap, and convenient spreader for
the lime-sulphur solutions, some experiments were conducted with
flour paste in combination with nicotine sulphate upon the hop aphis
(Phorodon humuli Schrank). (See Table IL.)

TABLE II.—Results obtained by spraying with combinations of flour paste and

nicotine sulphate in different proportions against the hop aphis, Sacramento
Valley of California, 1912.

| Number Aphides pair ie

Formula. of aphides} ~*
present. | Killed. | pattons.
| Per cent.| Cents.
Nicotine sulphate, 1-2,000; flour paste, 4-100...............-----..-------- 627 100 0.
Nicotine sulphate, 1-2,500; flour paste, 4-100............-....-----.---- es 611 100 - 60
Nicotine sulphate, 1-3.000; flour paste, 4-100..............--..------------ 1, 668 99 - 50
Nicotine sulphate, 1-3,000; flour paste, 4-100...............-...--.-.------ 148 99 -50

From the preceding table it is very evident that flour paste, 4-100,
is a very effective spreader for nicotine sulphate.

The efficiency of flour paste as a spreader was very evident to the
writer, but it was deemed advisable thoroughly to illustrate this point.

FLOUR PASTE AS A CONTROL FOR RED SPIDERS. 3

Two hopvines were accordingly sprayed, one with lime-sulphur
straight and the other with lime-sulphur and flour paste, 4-100.
The relative spreading effect of these two sprays is shown in fig-
ure 1. The left half of the figure represents the lime-sulphur and
the flour paste in combination, while the right half represents the
lime-sulphur straight. The spotted effect produced by the lime-
sulphur mixture alone is in strong contrast to the even appearance
of the other half of the illustration.

During some spraying experiments with nicotine sulphate and
flour paste upon the hop aphis it was observed that many of the
smaller aphides had become pasted onto the leaves. From this data
it was assumed that a stronger solution of paste would be effective
against the more delicate aphides and mites, and the following
experiments were conducted upon the red spider.

TABLE III.—Results of erperiments with flour paste sprayed against the red
spider on hops in the Sacramento Valley of California, 1912.

Number . Cost per
Date. Formula. of mites fore 100
present. * | gallons.
Per cent.| Cents.
TRNew OE MONT DASE SLO. 22. 3.25 = Seo acs ese e ene aetoeee ee 435 100 17.6
June).27 |. =~ COO ea oe oo ee er a a See Fe a ee 781 99.8 17.6
Anat bg 1 7) ae OSA ae Se Bee Ps Sos Gags Sok De eee 452 99.8 17.6
Aue, 6:|- 2 Gy ieee SpO bean aa eet ne A eee SE en ss Ses eet 882 100 17.6
Baa GORE See tea ea ete sek ced ee 02S rake eee eee ae 477 100 17.6
Aug: 9) )..-.< (0 C0 Oe i a RE ae RR Sc rh ee 732 99.8 17.6
SRO LAN COM Muse ssc ie ite cin sos Eee eee orcas Dara ae Sit eee a Ee eon
PASV BIAS Cees ee eos eee oi a's ees Sat deo nar One| Beosreodes CBee ae ae
July 16 | lou paste, 1OS1O0 he oe os | Kos eee See eee ae ee 805 99.9 22
ATig. 6:25 -2 er ee Ree ee en aals De mie ae At ee nc ee: ames 908 99.9 22
Motalicounter 22.4 - 28528 scene eee eset i Dy Psa ene Sooo
PA VOLAL Om ecb cupclsra sia =e sa asssie dis aeeltae sans ood 2 ee eee oe mee aoe D9 Oh asa eee

These experiments prove that flour paste, 8-100 and 10-100. is
effective against Tetranychus bimaculatus. The paste has no effect
upon the eggs, however. and in controlling the mites a second
application 7 to 10 days after the first is necessary to catch the mites
that emerge from the eggs."

A few preliminary experiments were conducted with this material
upon Tetranychus mytilaspidis Riley which was attacking pears, with
very encouraging results, and it is very probable that flour paste,
8-100, will give good results when apphed for any of the small leaf-
feeding mites.

The last of June, 1912, flour paste, 8-100, was applied for the hop
aphis (then in the younger stages) with a 97 per cent efficiency.
These were encouraging results, but later experiments proved that,

‘In moderate weather allow 10 days and in hot weather 7 days between
applications.

4 FLOUR PASTE AS A.CONTROL FOR RED SPIDERS.

although the solution was effective against some very delicate species
and the younger stages of the hop aphis, it was not effective against
the stouter aphides.

When the paste was dry the mites and more delicate aphides
treated were found firmly pasted onto the leaves. Later the paste
film was observed to crack and partially scale off, leaving the leaf
free to perform its natural functions.

The neutrality of this spray was proved by the fact that when
2pplied upon the foliage and blossoms of the hop in proportions as
high as 12 pounds to 100 gallons no injurious effect resulted.
When sprayed onto the burrs and delicate hop cones it did not pre-
vent pollination or injure the appearance of the scales.

Flour paste has proved effective when apphed for red spiders upon
the following plants:

Beans. Pumpkin.
Chrysanthemum (may spot leaves if | Pear,
used too near blossoming time). Prune.
Hops. Roses in field.
Cucumber, greenhouse and field. Violets, field and greenhouse.

The flour paste was not satisfactory when used for the red spider
on greenhouse roses (did not spread well), greenhouse carnations, or
field sweet peas.

PREPARATION OF PASTE.

To prepare the flour paste, mix a cheap grade of wheat flour with
cold water, making a thin batter, without lumps; or wash the flour
through a wire screen with a stream of cold water. Dilute until there
is 1 pound of flour in each gallon of mixture. Cook until a paste is
formed, stirring constantly to prevent caking or burning. Add sufh-
cient water to make up for evaporation.

Flour paste may also be prepared by stirring boiling water into
a moderately thin batter until there is 1 pound of flour in each
gallon of mixture and allowing it to stand until the starch is all
broken down.

If the paste is not sufficiently cooked, the resulting spray will not
be effective, and if overcooked the paste will harden when thor-
oughly cool, and will not mix with water very readily. Usually,
however, the paste is used as it is prepared, and overcooking is not
a disadvantage.

When mixed in the spray tank flour paste has a tendency to settle,
and in order to do satisfactory work agitation is necessary. This
is but a slight disadvantage, and is necessary with most materials.

Flour paste appears to be a very effective spreader for lime-sul-
phur and nicotine-sulphate sprays. Cheap flour can be purchased

FLOUR PASTE AS A CONTROL FOR RED SPIDERS. 5

for less than half the cost of whale-oil soap. It is always obtain-
able, and having no odor it is less offensive to use than the whale-
oil and fish-oil soaps. When used alone at the rate of 8 gallons (8
pounds flour) to 100 gallons of water it is effective against several
leaf-feeding mites and some very delicate aphides. The possibility

Fic. 2.— Hindu making flour paste, Sacramento Valley, Cal., 1912. (Original.)

of its use as a spreader for lime-sulphur sprays for scale insects and
fungi and as a “ sticker ” for arsenicals has not yet been worked out,
but from observations during the past four months it is believed that
it may have some value along these lines.

Approved:

JAMES WILSON,
Secretary of Agriculture.
Wasuineton, D. C., November 23, 1912.

DDITIONAL COPIES ofthis publication
may be procured from the SUPERINTEND-
ENT OF DOCUMENTS, Government Printing
Office, Washington, D. C., at 5 cents per copy

SMITHSONIAN INSTITUTION LIBRARIES

eA

9088 01272 8358