The fall armyworm (Spodoptera frugiperda) is an invasive and devastating pest that can cause huge losses. While it can attack any crop and reduce its foliage into something you would not want to see, the pest majorly affects maize (white and yellow), sugarcane, and sorghum. Unfortunately, the fall armyworm (FAW) can be difficult to control especially if you don’t understand the basics and use the right approach.
How Does the Fall Armyworm Develop?
The main stages of the FAW development are egg, larva, pupa, and adult. Out of the four, the larva and the adult moth are the most destructive. Larvae emerge 3-5 days after the adult moths lay the eggs.
When the larvae are young, they partially feed on leaves, causing transparent feeding windows. They will grow bigger and continue causing massive destruction until they reach around 3-4cm. Mature larvae are identifiable with their lightly-coloured inverted Y on the face.
Why Fall Armyworm Is Difficult to Control
Below are the characteristics and behaviors of the FAW that make it difficult to manage the pest:
- The Fall Armyworm Reproduces Quickly
Fall armyworm reproduces quickly. The lifecycle takes about a month in warm temperatures, thus FAW can have up to 12 generations in one year. With adult females laying up to 2,000 eggs in their lifetime, the population of fall armyworms can grow quickly within a short period.
- Fall Armyworm Moths Are Highly Mobile
Fall armyworm moths can fly long distances assisted by wind. In a single night, they can cover up to 100km. Therefore, these pests can traverse different counties in Kenya and lay their eggs within a few nights. The high mobility makes it hard to predict and prevent their spread.
- The Pest Can Feed On Different Crops
Although the fall armyworm prefers maize, it is polyphagous and can attack other crops including vegetables. The pests can survive in different cropping systems, thus adding complexity to management efforts. If the pests come across cotton, sorghum, or other crops during their migration, they can still feed, reproduce, and thrive.
- Fall Armyworm Feed at Night
Fall armyworm larvae are nocturnal. They feed at night, thus difficult to detect and monitor their activity.
- Fall Armyworm Larvae Can Hide within the Plant Structure
Fall armyworm has a cryptic tendency where they hide within the whorls of the maize crop. This behavior protects them from predators such as ants, birds, and bats and control agents such as parasitoid wasps. Further, it becomes difficult to see and reach them with various control measures.
- The Pest Has Overlapping Life Stages
The lifecycle of the FAW consists of the egg, larva, pupa, and adult. Unfortunately, the egg, larva, and pupa are present simultaneously within a population. Control measures become difficult since you must target each life stage to manage the pest effectively.
Fall Armyworm Management Plan
Here’s how you can avoid suffering heavy losses from fall armyworm:
- Plant Early
Plant early at the recommended time and take advantage of the first rains of the season. Your crop will reach the critical stages earlier before the fall armyworm infestation builds up.
- Ensure Good Crop Health
Stunted crops are easily overwhelmed by pests. If you choose good quality seeds, plant at the right spacing, and ensure good crop nutrition, you will have vigorous plants and avoid major losses that may occur with a slight infestation by pests.
- Early Detection
Detecting the fall armyworm early has several advantages. You will implement control strategies before the pest has caused massive destruction. Besides, you will have a better chance of managing the pest when the population is low. Therefore, regularly keep an eye on your crop. Be keen, especially during the whorl and pre-tassel growth stages when the maize is highly susceptible to larvae infestation.
- Chemical Control
Using a combination of cultural practices can help manage pest infestation. But when these practices do not yield, you may consider chemical control. Examples of chemicals (active ingredients) available in the Kenyan market for control of fall armyworm include:
- Emammectin benzoate
- Lufenuron
- Acephate
- Indoxacarb
- Pryriproxyfen
- Chlorathraniliprole
When you have basic information about the fall armyworm in Kenya, managing the pest becomes less challenging. Avoid planting your crop late into the season when infestation has built up. Further, regularly monitor your fields so that you implement a control plan before the pest wreaks substantial havoc on your farm.