KNOWLEDGE FOR LIFE
The Fall Armyworm caterpillar causes severe damage to over 80 plant species
including maize, rice and pastures by feeding on leaves, fruits and grains.
How to manage...
• Sow at the onset of rains to avoid peak immigration of adults
• Plant your crops at the same time – avoid having plots of
different ages
• Conserve beneficial insects which kill the armyworms by
preserving weeds and flowering plants on the edges of your plot
• Intercrop maize with crops such as cassava or yam, which are
not attacked by the Fall armyworm
PREVENT MONITOR
• Handpick and destroy egg masses and caterpillars.
• Spray with:
– Neem-based products
– Biopesticide Bacillus thuringiensis varieties in the late afternoon
– If you use chemical pesticides seek advice on which to use
from your Agricultural Extension Officer
Spray into the whorl. Ensure you wear long sleeves and trousers
along with a mask, goggles, gloves and boots while spraying
because chemical pesticides can be toxic.
Avoid spraying pesticides early in the crop cycle as this will kill
natural enemies that control the pest, and may not be economical.
ACT
For more info on Fall armyworm please visit:
www.plantwise.org/fallarmyworm
4. Adult moth
3. Caterpillar with y on head
2. Young caterpillars
1. Egg mass 5. Caterpillar damage
Check your crops weekly once they have emerged for signs of
damage.
Eggs : Look for egg masses on the undersides of the leaves
(picture 1).
Caterpillars : Look for caterpillars on the undersides of leaves and
the whorl. They are light green to dark brown with stripes down
their bodies.
Large caterpillars have an upside down pale Y-shaped marking
on the front (picture 3) and their second-to-last body segment has
four dark spots in a square shape.
Damage : Look for small light coloured patches and large ragged,
elongated holes on the leaves, emerging from the whorl (picture 5).
• Note how many plants in 100 are recently damaged.
•
Consider taking control measures if more than 20 whorls are
damaged and caterpillars can be found on plants.
Picture 4 (Adult moth) © Matt Bertone. All others © D Van Heerden.
