How can I monitor and scout for fall armyworm?

Learning Objective:

Participants should be able to identify ways to effectively monitor and scout for fall armyworm.

Monitoring for FAW is one of the most important activities for successfully managing FAW. Farmers should monitor the maize crop regularly, at least every 7 days, and no less than 10 days. Use the following resources to learn how to scout for FAW in the field.

It is also useful to be able to differentiate between the different larval stages of FAW because it is easier to control FAW in early larval stages.

Picture from the Fall Armyworm in Asia: A Guide for Integrated Pest Management (2021) (Image credit Suhrid Barik, Corteva),

When scouting for FAW, understand the different levels of leaf damage. The Davis scale has been developed to rate the extent of leaf damage.

Scale

Description

0

No visible leaf damage.

1

Only pinhole damage on leaves.

2

Pinhole and shot hole damage to the leaf.

3

Small, elongated lesions (5–10 mm) on 1–3 leaves.

4

Midsized lesions (10–30 mm) on 4–7 leaves.

5

Large, elongated lesions (>30 mm) or small portions eaten on 3–5 leaves.

6

Elongated lesions (>30 mm) and large portions eaten on 3–5 leaves.

7

Elongated lesions (>30 cm) and 50% of leaf eaten.

8

Most leaves with long lesions and complete defoliation observed.

9

Elongated lesions (30 cm) and large portions eaten on 70% of leaves.

Read

Read this FAO Guidance Note for instructions on how to undertake scouting in the field.

Watch

Watch this SAWBO video to see a farmer undertake simplified scouting in the field. You can access this video in different languages.

Listen

Listen to this farmer talk about scouting in his field. 

Search

Hear from this expert on why it is important it is to monitor