\m    28   11   32    2  1 'Control of Insect Pests in Stored Grain'
\m    29   11   80    2  2 'General Introduction'
\m    68   27   38    3  2 'List of Stored Grain Pests and Some Biological Data'
\m   112   43   16    4  2 'Reducing Insect Populations Before Storing'
\m   113   43   67    4  3 'Resistant Varieties'
\m   123   45  107    4  3 'Clean-up of Storage Bins'
\m   134   49   67    4  3 'Residual Bin Sprays'
\m   156   59   51    4  3 'Protecting Grain When Loading Bins'
\m   171   64   86    5  3 'Treatment for Grain During Loading'
\m   212   79   17    6  3 'Surface Treatments'
\m   253   92  111    7  2 'Fumigation'
\m   254   93    2    7  3 'General Information'
\m   298  113  125    8  3 'Methyl Bromide'
\m   355  136   17    9  3 'Aluminum Phosphide'
\m   374  143   39    9  3 'Precautions'
\m   387  147  100   10  1 'Control of Insect Pests in Stored Peanuts'
\m   388  148   22   10  2 'Clean-up of Storage Warehouses'
\m   398  150   96   10  2 'Residual Warehouse Sprays'
\m   414  158    5   10  2 'Bulk Spray of Peanuts'
\m   424  160  113   10  2 'Supplemental Surface Sprays'
\m   433  163   97   10  2 'Fumigation'
\t'November 1987'                                                 'VIII-'
\a                   Dr. Phil Koehler, Extension Entomologist
\a
\a                         CONTROL OF STORED GRAIN PESTS

                   Dr. Phil Koehler, Extension Entomologist
\h 1 'Control of Insect Pests in Stored Grain'
\h 2 'General Introduction'


                         CONTROL OF STORED GRAIN PESTS

                              General Introduction

Stored grain of almost any kind is subject to attack by insects.  The insects
which attack stored grain are highly specialized to exploit the stores man has
set aside for himself.  Stored products insects are, in most cases, insects of
small size with a high reproductive potential.  Therefore, they are easily
concealed in grain and grain shipments and have been carried to all parts of
the world.  Once established in a commodity they are usually difficult to
control.

In general, stored products pests thrive in warm, humid environments.  Grain
with high moisture stored in warm conditions is usually most susceptible to
insect infestations.  Stored grain pests are important since they contaminate
food, lower its nutritive value and create conditions favorable for mold
growth.

Pests which attack whole grain usually develop and feed inside the kernels of
grain.  They can be easily overlooked in grain shipments since they cannot be
seen.  These pests are not usually capable of existence outside the grain
kernel as immature insects.  Examples of whole grain pests are the rice
weevil, the granary weevil, the lesser grain borer, and the angoumois grain
moth.

Other insects which attack grain are usually unable to penetrate whole grain.
These insect pests however, can attack grain after it has been either
mechanically broken or attacked by whole grain insects.  Examples of these
secondary pests are the red and confused flour beetles, Indian meal moth,
Mediterranean flour moth and the sawtoothed grain beetle.

Grain may become infested in a number of ways.  One of the most common means
of infestation starts in the field.  In Florida, it is not uncommon for
freshly harvested corn to have a 10% infestation rate.  Another common means
of infestation is storing grain in or near infested storage facilities.
\b\v
\h 2 'List of Stored Grain Pests and Some Biological Data'
\v
\v
              List of Stored Grain Pests and Some Biological Data

It is important to know the stored grain pests and inspect according to the
length of time it takes to complete a life cycle.
-------------------------------------------------------------------------------
                        Time Required for
Grain Pests             Complete Life Cycle                Remarks
-------------------------------------------------------------------------------
granary weevil          4 weeks              Universal feeder on whole grains.

rice weevil             26 days              Universal feeder on whole grains.
                                             Most common stored whole grain
                                             pest in Florida.

broad-nosed grain       4 weeks              Usually attacks soft or damaged
   weevil                                    grain.

coffee bean weevil      4 weeks              Lays eggs in corn in field
                                             infestations, may continue for 3
                                             months after storage.

lesser grain borer      4 weeks              Universal feeder on whole grains.

angoumois grain moth    5 weeks              Most important in stored corn.

rice moth               6 weeks              General feeders.

Indian-meal moth        6 - 8 weeks          Prefers coarse grades of
                                             processed grain.

Mediterranean flour     8 - 9 weeks          Prefers finer grades of
   moth                                      processed grain.

sawtoothed grain        4 weeks              Prefers grain products.
   beetle

confused flour beetle   6 weeks              Attacks grain and grain products.

red flour beetle        5 weeks              Attacks grain and grain products.
-------------------------------------------------------------------------------
\b\v
\h 2 'Reducing Insect Populations Before Storing'
\h 3 'Resistant Varieties'
\v
\v
                    Reduce Insect Populations Before Storing

Resistant Varieties:

Grow resistant varieties if available.  Some varieties of corn have
characteristics such as long tight husks that will help to keep down weevil
and other insect damage.
\h 3 'Clean-up of Storage Bins'


Clean-up of Storage Bins:

Store grain only in bins that have been cleaned thoroughly of waste materials
such as old grain, trash, or feed sacks that may furnish living quarters for
insects.  Sweep down ceiling, walls, rafters, beams and other areas where old
grain and dust can lodge.  Clean up old grain around and beneath the bins.
Burn or bury all refuse collected during the clean-up.  See section on
residual bin sprays.
\h 3 'Residual Bin Sprays'


Residual Bin Sprays:

-------------------------------------------------------------------------------
Insecticide                Dilution                        Directions
-------------------------------------------------------------------------------
43.2% chlorpyrifos-     1/2 pt. per 6.5 gal. water   Treat empty bins prior to
  methyl EC                                          to filling.  After clean-
                                                     ing bins thoroughly, spray
57% malathion EC        1 gal. per 25 gal. water     walls, floors and ceilings
   (premium grade)                                   to the point of "run off"
                                                     (2 gal/1000 sq ft). Apply
25% methoxychlor EC     1 gal. per 4 gal. water      the insecticide 2-3 weeks
                                                     before harvest. Before
50% methoxychlor WP     1 lb. per 3 gal. water       storing the grain, sweep
                                                     the bin to remove all dead
.15% pyrethrins +       Ready-to-use                 insects.
   1.5% piperonyl
   butoxide
-------------------------------------------------------------------------------
\h 3 'Protecting Grain When Loading Bins'


Protect Grain When Loading Bins:

The use of an approved insecticide is an effective way to control stored grain
insects, providing the grain being stored is not already heavily infested and
the moisture content is not above 12%.  (High moisture grain attracts insects
and enhances more rapid breeding than does dry grain.)

Grain treated with protectants should be inspected at monthly intervals to
guard against the possibility of infestation.  These inspections should not be
limited to the surface of the grain, but should extend down into the grain. If
treated grain becomes infested, it can be fumigated.
\b\v
\h 3 'Treatment for Grain During Loading'
\v
\v
Treatment for Grain During Loading:

-------------------------------------------------------------------------------
Insecticide          Product    Directions
-------------------------------------------------------------------------------
57% malathion EC     wheat,     Mix 1 pint of 57% EC in 2 - 5 gal. of water
                     oats,      per 1000 bushels of grain. Spray grain evenly
                     rice       as it is loaded or turned into final storage.
                                Complete coverage is essential.

1% malathion dust    corn,      Apply uniformly at 60 lb.  per 1000 bushels.
                     rye,       Use only malathion labeled "premium grade" on
                     barley,    grain. Grain treated with protectant can be
                     grain      fed safely to livestock
                     sorghum,
                     field and
                     garden seed

43.2% chlorpyrifos-  wheat,     Mix according to label directions.  Apply
  methyl EC          oats,      1-5 gal per 1000 bushels.  Do not use on corn.
                     rice,
                     sorghum,
                     barley

3% chlorpyrifos-     wheat,     Apply 11.5 lb/1000 bushels of wheat,
  methyl dust        oats,      9.2 lb/1000 bushels of oats or barley.
                     rice,      Do not use on corn.
                     sorghum,
                     barley

Bacillus             stored     Apply at rate of 3/4 lb. per 100 bushels.
  thuringiensis      grains &   Apply uniformly to grain stream.
  (Dipel)            soybeans
                      (Indian
                       meal moth,
                       Almond moth)
------------------------------------------------------------------------------
\b\v
\h 3 'Surface Treatments'
\v
\v
Surface Treatments:

Surface treatments are applied to prevent insects from entering the grain from
the outside.  Certain insects mainly damage surface grain first.
-------------------------------------------------------------------------------
Insecticide          Product    Directions
-------------------------------------------------------------------------------
57% malathion EC     stored     Apply 1 pint in 2 - 4 gal. of water per 1000
                     grain &    sq. ft. of grain surface. Apply evenly over the
                     field &    over the grain surface immediately after grain
                     garden     is loaded into storage.  Repeat if necessary.
                     seed

1% malathion dust    stored     Apply to grain surface at rate of 30 lb. per
                     grain &    1000 sq. ft.
                     field &
                     garden seed

43.2% chlorpyrifos-  wheat,     Apply 3 oz (wheat), 2.4 oz (barley), 1.6 oz
  methyl EC          barley,    (oats) in 2 gal of water per 1000 sq ft of
                     oats,      grain surface.
                     rice,
                     sorghum

3% chlorpyrifos-     wheat,     Use 7 lb per 1000 sq ft of grain surface.
  methyl dust        barley,
                     oats,
                     rice,
                     sorghum

Bacillus thurin-    stored     Apply 1 lb. of WP in 10 gal. of water per 500
  giensis  (Dipel)  grains &   sq. ft.  Mix into top 4 inches.
                    soybeans
                     (Indian
                     meal moth,
                     Almond moth)
-------------------------------------------------------------------------------
\b\v
\h 2 'Fumigation'
\h 3 'General Information'
\v
\v
                                   Fumigation

General Information:

Fumigation is the most commonly used method of controlling insects that infest
stored grain.  It kills insects and eggs present at the time of fumigation,
but does not protect the grain from reinfestation.  In Florida, grain should
be fumigated as it is being loaded or turned.  Inspect at least once a month.
It will probably be necessary to fumigate the grain more than once.  The
spring following harvest is a likely time for an additional fumigation.  Seal
all cracks and holes in the bin to make it as gas tight as possible.  Be sure
all ventilators are closed during the fumigation.  Many instances of poor
control, charged against the fumigant, are due to bins that are not tight.

The Environmental Protection Agency has initiated a "Label Improvement Program
for Fumigants" to help minimize occupational exposure to fumigants.  Changes on
the label to better define user information, warnings and necessary precaution-
ary measures will directly affect how fumigants are used and who uses them.
Three features of the program are of prime importance:  (1) The revised label
will direct that two "trained persons" be present during the principal
fumigation operation, especially if entry into the structure under treatment
is required for application of the fumgiant;  (2) The use of approved
respirator protection devices will be required during application of the
fumigant when concentrations of the fumigant exceed prescribed levels or if
the concentrations are unknown;  (3) Specified direct-reading detector devices
would be required to monitor fumigant concentrations to prescribed levels as a
condition of re-entry or transfer to treated grain.

It is often safer, less expensive, and more effective for farmers to have their
stored grain fumigated by a licensed and certified professional fumigator.  The
most important factor to consider when deciding whether to hire a professional
to do a fumigation is the personal risk involved in the handling and application
of these highly toxic chemicals.  A professional fumigator will have the
knowledge and experience required to conduct effective treatment and will also
have the special equipment needed to apply fumigants properly.  In addition,
professionals will have safety equipment such as gas masks or other respiratory
protection which are expensive but necessary when applying any fumigant.
However, professional fumigators are not always available to service farm-stored
grains and many farmers still prefer to handle this phase of pest management
themselves.
\b\v
\h 3 'Methyl Bromide'
\v
\v
Methyl Bromide:

Methyl Bromide is an economical fumigant available for control of stored grain
insects.  Methyl Bromide fumes are highly toxic to humans and animals.  It
should not be used to fumigate seed corn.

Instructions:  For best results, Methyl Bromide should be recirculated through
the grain in a closed aeration system.  Ventilating or aerating systems can be
turned into recirculation systems by returning the air from the storage area
to the blower.  Usually savings of 50% on fumigant costs can be realized by
the recirculation method.

Methyl Bromide gas is inserted into the air circulation system with little
trouble.  After 24 hours, the Methyl Bromide can be removed from the storage
area rapidly.



               DOSAGE OF METHYL BROMIDE FOR RECIRCULATION SYSTEMS
-------------------------------------------------------------------------------
Type of Grain              Grain Temperature         Dosage (lbs/1000 cu ft)
-------------------------------------------------------------------------------
wheat, corn, rice          above 80 F                          1.5
wheat, corn, rice          60 - 80 F                           2.0
wheat, corn, rice          below 80 F                          2.5
grain sorghum              above 80 F                          3.0
grain sorghum              below 80 F                          4.0
_______________________________________________________________________________
Precautions: Do not breathe vapors.  Read and follow all directions and
   precautions on the label and technical manuals.


To apply Methyl Bromide without a recirculation system, place a pan or other
receptacle on the surface of the grain at the center of the bin.  Stretch
tubing from receptacle to the outside of the bin.  Place an open crate or
other frame over the receptacle and spread a plastic cover over the frame and
grain surface.  Seal the door and prepare to release Methyl Bromide.  Use the
special applicator, Star Model 1.5 opener and follow label instructions.



             DOSAGE OF METHYL BROMIDE FOR NON-RECIRCULATION SYSTEMS
                        (Temperature must be above 60 F)
-------------------------------------------------------------------------------
Volume (cu. ft.)                Rate (lb./1000 cu. ft.)
-------------------------------------------------------------------------------
less than 100,000                    1.5 - 3
100,000 - 500,000                    1.25 - 1.5
500,000 - 1,000,000                  1.0 - 1.25
more than 1,000,000                  1.0
_______________________________________________________________________________
Precautions: Do not breath vapors.  Read and follow all directions and
   precautions on the label and technical manuals.
\b\v
\h 3 'Aluminum Phosphide'
\v
\v
Aluminum Phosphide:

In recent years Aluminum Phosphide (Celphos, Delicia, or Phostoxin) has been
found to be an effective fumigant for stored grain insects.  The main
advantage of Aluminum Phosphide is the ease of application.

Instructions: Aluminum Phosphide is available as tablets, and the fumigant is
released due to moisture in the air.  Keep tablets away from liquid water.
Always open container in open air.

For treatment of grain pests in rice, wheat, barley, corn, oats, sorghum,
millet and rye, the Aluminum Phosphide tablets may be injected into grain with
a probe or fed into grain stream as it is flowing into the bin.  Grain
temperature must be 40 F for fumigation.  Effective dosages are 6 tablets per
ton of grain or 180 tablets per 1000 bushels.  The exposure time required is 5
days (54 - 59 F), 4 days (60 - 68 F), or 3 days (warmer than 68 F).
\h 3 'Precautions'


Precautions:

Follow all precautions given on the label of the insecticide you use.  All
fumigants mentioned give off poisonous vapors.  They have an anesthetic
action, and a worker may be suddenly over-come without noticing adverse
symptoms.  Therefore, never fumigate grain without the assistance of another
person, and never stay inside the bin unless you are protected by a gas mask
approved for the type of fumigant you are using.  If any fumigant is spilled
on the skin, it should be washed off immediately with soap and water.
\b\v
\h 1 'Control of Insect Pests in Stored Peanuts'
\h 2 'Clean-up of Storage Warehouses'
\v
\v
\v
                   CONTROL OF INSECT PESTS IN STORED PEANUTS

                         Clean-up of Storage Warehouses

Clean warehouse thoroughly of trash and remains of old peanuts 1 - 2 weeks
before new crop is stored.  Burn or bury all refuse collected during clean-up.
\h 2 'Residual Warehouse Sprays'


                           Residual Warehouse Sprays

-------------------------------------------------------------------------------
Insecticide             Dilution                  Directions
-------------------------------------------------------------------------------
57% Malathion EC        1 gal per 19 gal water    Spray interior thoroughly,
  (Premium Grade)                                 especially cracks. Treat
                                                  outside walls to a height
25% Methoxychlor WP     1 gal per 10 gal water    of 6 - 8 ft. and the ground
                                                  6 ft. from the warehouse.
                                                  Do not load warehouse until
                                                  spray has dried.
-------------------------------------------------------------------------------
\h 2 'Bulk Spray of Peanuts'



                             Bulk Spray of Peanuts

Apply coarse spray uniformly to peanuts while loading for storage.  Malathion
(premium grade) 57% EC should be diluted at a rate of 2.5 pints in 5 gallons
of water and sprayed on 15 tons of peanuts.  It is important to spray for
complete coverage while loading peanuts.
\h 2 'Supplemental Surface Sprays'


                          Supplemental Surface Sprays

After filling warehouse, level surface and spray with 1.75 pounds of 25%
malathion WP in 2 gallons of water for each 1000 square feet of surface.
Apply first treatment as soon as bin is filled.  Apply second treatment one
month later.  Repeat at two month intervals.
\h 2 'Fumigation'


                                   Fumigation

Methyl bromide and aluminum phosphide are cleared for peanut fumigation.
Refer to stored grain fumigation for directions, warnings and procedures.
