CONTROL OF STORAGE INSECT PESTS Preventative measures post harvest losses sanitation

1. CONTROL OF STORAGE
INSECT PESTS
PREVENTIVE MEASURES

2. INTRODUCTION
• Insect pests can infest mature pre-harvested and post
harvested grains causing extensive post-harvest losses,
spoilage, and reduced prices or rejection of grain by buyers.
• The most effective way to manage stored grain pests is to
avoid them
• Effective control of stored grain pests without synthetic
pesticides requires an IPM approach preventive and curative
measures.

3. Preventative measures
• Preventive measures include practices such as sanitation, grain
cleaning, monitoring of stored grain, monitoring grain temperature
and aeration, preparation and maintenance of storage facilities and
inspection,

4. Sanitation
• The most effective way to manage stored grain pests is to avoid them.
• The goal of sanitation is to eliminate insect eggs, pupae, and adults.
Never put newly harvested grain into bins containing old grain
• Involves removing dirt, debris, mud balls, foreign particles, insects
and infested grains from healthy grains that will reduce insect
infestation.
• Proper handling of grains and avoiding hooks on storage bags help
minimize exposure to insects
• Dis-infestation of storage structures with insecticides

5. Sanitation cont’
• Proper drying to bring down the moisture content the recommented
for storage for example 7% to 9% for oil seeds and 10% to 12% for
cereal crops
• Use of improved storage structures such as silos

6. Grain cleaning
• Before storing the harvested grain in the storage structures, clean the storage structures thoroughly by :
• Eliminating dust and dockage from any cracks in the storage structure.
• Repairing holes, cracks and leaks in the storage structures and cracks in the floor if it is concrete.
• Clean under the floor grates.
• Apply approved insecticides to disinfest grain storage structures
• For temporary storage - clear area of all debris and ensure area is graded so that water flows away from the
grain.
• Remove dirt, debris, mud balls, foreign particles, insects and infested grains from healthy grains that will
reduce insect infestation
• Fine materials, including insects and insect parts, have an affinity for moisture, mold, and insect infestations.
• Proper combine adjustment should be used to reduce the amount of grain breakage, fines, and foreign
material.
• A grain cleaner can be used to improve storability

7. Grain Monitoring and inspection
• One of the best ways to prevent insect infestations is to Inspect and
monitor grain regularly.
• If an infestation is detected early, insects can be controlled before
they cause extensive damage
• Check the grain for heating and off-odors and monitor stored grain
every 2 weeks to detect early signs of deterioration or infestation.

8. Fumigation of storage structures
• All fumigants are dangerous if improperly used so there is need to
follow the cautions listed on the container label and use only in strict
accordance with label directions.
• Always use the recommended dosage of an approved fumigant for
the type of grain and type of structure you are treating. Make a
special effort to make the grain bin airtight. Level the grain surface to
insure even penetration of the fumigant throughout the grain mass
• Fumigants are available in liquid, gas, and solid formulations.
However, they all must become a gas to be effective as a fumigant.

9. Temperature control and aeration
• It is important to monitor grain temperature and to keep stored grain cool and dry by
regular aeration.
• High moisture and warm temperatures in grain allow for the rapid growth of insects,
fungi and the possible production of mycotoxins.
• Grain is a very good insulator, when it is undisturbed, it holds temperature well. If warm
grain is placed into storage and left undisturbed, convection currents develop and cause
hot spots and moisture condensation. The greater the temperature differential (the
difference between the temperature of the grain and the outside temperature), the
stronger the convection currents. The stronger the convection, the greater the effect of
heating and condensation on the grain.
• Aeration systems preserve stored grain and keep it dry by reducing the temperature of
grain and reducing moisture migration. Appropriate aeration can prevent convection
currents and condensation from occurring.
• It is important to consider the physical characteristics of grain when considering aeration
and drying.