The Fall Armyworm (Spodoptera Frugiperda) is a pest that can cause economic damage to crops if left to multiply. They mainly attack the maize crop but once its food crop is exhausted, will eat the next available crop including barley, millet, peanuts, rice, sorghum, soybeans, wheat, etc.
Fall armyworm (FAW) [Spodoptera frugiperda] is an insect pest with moths as the adult stage and larvae (caterpillars) as the destructive stage.
In Kenya, the pest was first reported in March 2017 in Western Kenya and has since spread countrywide. The pest attacks a wide range of crops but maize and sorghum are the most preferred hosts. It can cause up to 100% yield loss if left uncontrolled.
Identification of Fall Armyworm
Fall armyworm has 4 main stages of development: Egg, Larva, Pupa, and Adult.
The complete life cycle takes 40-47 days depending on the prevailing weather conditions. It takes short periods under warm conditions.
- Fall armyworm adult moths lay eggs in batches on host plants, normally on young leaves.
- The white egg masses are normally covered with wool-/ cotton-like material of the adult moth scales.
- The larvae have 6 developmental stages (instars) that are the destructive stages and take the longest time in the life cycle.
Fall Armyworm Larvae
- It is dull yellow to grey in color with stripes running down the length of the body.
- When mature it is 1.5 to 2 inches long.
- There are 6 instars of the larvae stage.
- Young larvae are greenish with a black head. In the 4th to 6th instars, the head is brown with a white Y- inverted line in its face.
- The larvae conceal themselves during the brightest times of the day. The larvae stay about 14 days in warm weather and 30 in cool weather before pupation.
Fall Armyworm Pupa
- Pupation takes place in the soil.
- Duration in this stage is 8 to 9 days in warm weather.
Fall Armyworm Adult
- The moths are nocturnal and very active in warm humid evenings.
- The female normally deposits eggs in its first 4 to 5 days of life but up to 3 weeks. Adults live between 7 to 21 days.
- Their eggs are dome-shaped.
- The eggs laid per mass is between 100 to 200 and a female lays on average 1500 eggs. They reach a maximum of over 2,000 eggs. These eggs are attached to the foliage of plants.
- Eggs take only 2 to 3 days to hatch in warm weather.
Fall Armyworm Life Cycle
The life cycle is completed in 30 days in warm weather and 60 days in the spring and autumn seasons. In winter, they can take up to 90 days to complete their life cycle.
Fall Armyworm Feeding
The armyworms feed mainly on grasses particularly maize and small grain crops.
Infestation can be hard to detect because they move to other feeding areas at night. When they are nearing maturity, they can destroy the whole crop in very few days.
Indicators of Fall Armyworm Attacks
There are two ways of knowing whether a crop has a FAW attack:
1. Presence of any of the stages of fall armyworm (eggs, larvae, pupae, and adults).
2. Damage caused by fall armyworm larvae on an infested crop.
How to Identify FAW Caterpillars
- The 1st instar larvae are very small and dark grey in color. The 2nd and 3rd instars are greenish or yellowish-brown in color and have hair-like spikes.
- The 4th to 6th instars are brownish and have a characteristic light-colored “inverted Y” mark on the head front, which links with the middle thin stripe.
- There are 4 black dots in a square formation on the rear abdominal segment.
Signs of the presence of armyworms include:
- chewing/leaf scalloping along the leaf margins.
- caterpillar excreta or ‘frass’ which collects on leaves or at the base of the plant — these appear as green or yellow cylindrical pellets 1mm to 2mm long
- cereal heads or oat grains on the ground — oat grains may be attached to a small piece of a stalk (1mm to 2mm), whereas wind-removed grains are not, and barley heads may be severed completely or hang from the plant by a small piece of stalk.
- Young larvae (1st to 3rd instar stages) feed on leaves, causing transparent window pane-like damage, initially appearing as “scratch marks” on the leaf.
- Older larvae (4th to 6th instars) cause large ragged and elongated holes on leaves, leading to a shredded appearance.
- At the reproductive stages of the host plant, older larvae clip the tassels, make shot holes in ears and feed on grains.
- Larvae produce large amounts of frass (excreta) as they feed and grow.
List of Insecticides to Get Rid of Fall Armyworms
Tested and working Fall Armyworm Control Solutions
The surest way to control this pest currently is through known tough insecticide combinations. They are as follows;
- Escort 50ml + Pentagon 40ml ( Kill in 5 hours)
- Escort 50ml + Loyalty 10gm ( Kill in 5 hours)
- Profile 30ml + Pentagon 40ml (Kill in 5 hours )
- Ranger 40ml + Loyalty 10gm (Kill in 5 hours)
This is based on trials done on fall armyworm-infested maize farms in Makhele village, Saboti constituency, Trans Nzoia County.
Can Be Mistaken For
Cutworms are a similar pest that grows through a caterpillar-like larvae phase before transforming into a moth. Cutworms do not display the colorful, lengthwise stripes that make army worms easy to identify.
To get fast and efficient action for immediate results with control within hours of ingestion, it is advisable to order Fall Armyworm insecticides by contacting us at +254737898884, +254759292158, +254775145267, +254103055943, +254794265503, +254756432285, +254757668223, +254789231328, +254742448334, or drop an email to firstname.lastname@example.org.