Fall Armyworm Early Action Policy Guide

Abstract

When FAW arrives, many governments and farmers first think of eradicating the pest. Newly invasive pests can sometimes be completely eliminated, but FAW has several characteristics that make eradication extremely difficult. First, FAW is very mobile. Adult moths can travel 100 km in a night, and individuals can fly over 1 000 km in a lifetime. Second, FAW is very polyphagous-it feeds on, and can reproduce on, many different species of plants. This means that it can rapidly spread across many environments and cropping systems, and isn't restricted by diet. Finally, as the damage caused by FAW is sometimes confused by farmers with damage from other pests, confirmation of initial reports of FAW may at times be slow, allowing FAW to spread from its entry point before action is taken. The reality is that FAW rapidly moves across millions of hectares of maize and other plants and quickly becomes a problem for farmers. Unfortunately, there is no way for them to eradicate or eliminate FAW; once the pest is established, it will always be nearby. Farm management The widespread, or diffuse, nature of FAW infestations requires a different approach than many governments might be accustomed to if their experience has been in dealing with gregarious pests, such as locusts, which lend themselves to central government control methods. Such an approach works when the pest is aggregated into defined areas, which can then be targeted. But with a pest such as FAW, diffuse and widespread, centralized control is not effective. Instead, farmers must learn how to sustainably manage FAW in their cropping systems, and great attention should be given to working with farmers in the context of their production systems. Pheromone traps Early detection of FAW can be efficiently done using pheromone traps. FAO has developed guidance on their use. Much is known about the pheromones that attract the male moth to traps, where they can be counted and monitored. FAO has reviewed the results from various companies that sell pheromones and makes recommendations about which pheromones attract the FAW moths only. FAW FALL ARMYWORM EARLY ACTION POLICY GUIDE FAW GUIDANCE NOTE 5 Fall Armyworm (FAW) continues to spread into new territory, moving further east and north in Asia, as well as north from sub-Saharan Africa. As it spreads, more governments are faced with decisions about how to react quickly and sustainably to the arrival of this new crop pest. Fortunately, they can benefit from over two years' worth of experience gleaned from across sub-Saharan Africa as well as decades of experience from the Americas. The lessons learned there by governments, resources partners and farmers can help guide decision-makers now being affected by FAW. This policy guide reviews the experiences and lessons learned from over 40 countries that have had to make quick policy and technical decisions that have set the groundwork for sustainable management of FAW.

Full text

Eradication?
When FAW arrives, many governments and farmers
first think of eradicating the pest. Newly invasive
pests can sometimes be completely eliminated,
but FAW has several characteristics that make
eradication extremely dicult. First, FAW is very
mobile. Adult moths can travel 100 km in a night,
and individuals can fly over 1 000 km in a lifetime.
Second, FAW is very polyphagous – it feeds on, and
can reproduce on, many dierent species of plants.
This means that it can rapidly spread across many
environments and cropping systems, and isn’t
restricted by diet. Finally, as the damage caused by
FAW is sometimes confused by farmers with damage
from other pests, confirmation of initial reports of
FAW may at times be slow, allowing FAW to spread
from its entry point before action is taken.
The reality is that FAW rapidly moves across
millions of hectares of maize and other plants
and quickly becomes a problem for farmers.
Unfortunately, there is no way for them to
eradicate or eliminate FAW; once the pest is
established, it will always be nearby.
Farm management
The widespread, or diuse, nature of FAW
infestations requires a dierent approach than
many governments might be accustomed to if their
experience has been in dealing with gregarious
pests, such as locusts, which lend themselves to
central government control methods. Such an
approach works when the pest is aggregated into
defined areas, which can then be targeted. But
with a pest such as FAW, diuse and widespread,
centralized control is not eective. Instead, farmers
must learn how to sustainably manage FAW in their
cropping systems, and great attention should be
given to working with farmers in the context of their
production systems.
Pheromone traps
Early detection of FAW can be efficiently done using
pheromone traps. FAO has developed guidance on
their use. Much is known about the pheromones
that attract the male moth to traps, where they
can be counted and monitored. FAO has reviewed
the results from various companies that sell
pheromones and makes recommendations about
which pheromones attract the FAW moths only. FAW
FALL ARMYWORM
EARLY ACTION POLICY GUIDE
FAW GUIDANCE NOTE 5
Fall Armyworm (FAW) continues to spread into new territory, moving further east and north in Asia, as
well as north from sub-Saharan Africa. As it spreads, more governments are faced with decisions about
how to react quickly and sustainably to the arrival of this new crop pest. Fortunately, they can benefit
from over two years’ worth of experience gleaned from across sub-Saharan Africa as well as decades
of experience from the Americas. The lessons learned there by governments, resources partners
and farmers can help guide decision-makers now being aected by FAW. This policy guide reviews
the experiences and lessons learned from over 40 countries that have had to make quick policy and
technical decisions that have set the groundwork for sustainable management of FAW.
©FAO/A.Poisot

FAW GUIDANCE NOTE 5
pheromones and traps are used for monitoring
purposes, not controlling the pest. Pheromones
and traps will not reduce the population of female
moths that lay eggs, and do not suciently
reduce the numbers of male moths to aect FAW
populations.
Fall Armyworm Monitoring,
Early Warning System
(FAMEWS)
Monitoring FAW population levels over time and
space is very important to better understand
its ecology so that early warnings are received,
and action can be taken. FAO, in partnership with
PlantVillage at Penn State University in
Pennsylvania, has developed the Fall Armyworm
Monitoring and Early Warning System (FAMEWS)
to help farmers, communities, local authorities, as
well as national and international leaders make
the best use of resources to manage FAW. The
FAMEWS mobile app should be used every time an
infested field or a pheromone trap is checked for
FAW, as described in the guidance notes on FAW
scouting and FAW trapping. Data entered into the
app are displayed on the FAMEWS global platform.
All countries are encouraged to use the system
by entering all available data on a regular basis
to ensure the best possible early warnings, to
better analyse FAW movements and trends, and
to improve FAW management. The more data
provided, the better the results.
FAMEWS uses artificial intelligence (AI) and
integrates data from many sources, including
satellites, to provide farmers with oine advice
and recommendations. FAO’s collaboration with
PlantVillage at Penn State and Norway’s VIPS
service puts precise agricultural information,
predictions and recommendations for FAW
management into the hands of smallholders via
their smartphones.
©FAO/A.Poisot

FAW GUIDANCE NOTE 5
Use of pesticides
Often, the first reaction to FAW infestation
in new areas is to find pesticides and get
these into farmers’ hands. Although some
pesticides do kill FAW, their use for FAW
management should be carefully analysed
as there are a number of important
considerations.
Consider first and foremost the cost
and benefit of pesticides. While FAW
can cause some yield reduction, plants
have a capacity to compensate for foliar
damage and the yield loss is often less
than farmers or extensionists expect.
Studies show that even under high levels
of infestation, yield loss is rarely over 20
percent and often closer to 10 percent.
Another economic consideration is the
value of the lost yield – farmers often
receive low prices for their cereals sold
locally. These two factors combined – low
losses and low prices – means it makes
little economic sense for farmers to invest
very much in pecticides. One calculation
from Malawi showed that a farmer, to be
economically sensible, should invest only USD 7 per
hectare to manage FAW. This amount wouldn’t cover
the cost of pesticides in many cases.
Another consideration with pesticides is the fact
that older, dangerous chemicals are often still
available and used in programmes against FAW.
One African country was purchasing and giving
away carbosulfan, a pesticide de-authorized in
the European Union 10 years ago due to human
health hazards.
Often, the pesticides don’t work. Recent studies
from Ethiopia demonstrate that older compounds
in pesticides result in very low mortality of FAW
larvae in the laboratory. Even with compounds that
do work in the laboratory, eectiveness in the field
is often low, as the FAW larvae burrow deep into
maize and sorghum whorls and cover the entrance
with frass, making delivery of pesticides to the FAW
larvae very dicult.
Therefore, a hasty reaction to FAW by giving away
or subsidizing pesticides is not sustainable in most
cases, and leads farmers and government ocials
down the wrong road in their search for solutions.
Role of natural control
FAW has many “natural enemies” – those organisms
that are naturally in the environment and kill FAW
eggs, larvae and pupae. These organisms include
predators (ants, earwigs, birds, etc.), parasitoids
(tiny wasps that kill FAW eggs, larvae or pupae) and
pathogens (bacteria, virus, fungi and nematodes).
The cumulative eect of these agents on FAW can
be very high. Farmers can take actions to conserve
©FAO/A.Poisot

CONTACT US
MORE INFORMATION
Fall-Armyworm@fao.org
Food-chain-crisis@fao.org
http://www.fao.org/fall-armyworm/en/
Plant Production and Protection Division
Food and Agriculture Organization of the United Nations
Viale delle Terme di Caracalla, 00153 Rome, Italy
E-mail: AGP-Director@fao.org
FAW GUIDANCE NOTE 5
and attract these organisms to their fields,
increasing the mortality of FAW.
In the Americas, natural mortality in the field from
these naturally occurring organisms has been
consistently measured at between 30 per cent
and 90 percent. Although FAW is moving into new
territories, most of its natural enemies are already
in the cropping systems. This has been observed in
Africa and the Near East, where natural mortality
has already been documented in the field. One
study from Ethiopia found one parasitoid killing 34
percent to 45 percent of FAW larvae two years after
the confirmed arrival of FAW in the country.
Unfortunately, many of these organisms are killed by
pesticides. However, farmers can undo that damage
and increase populations of these organisms by
providing them with habitat and food sources. Farmers
and researchers report very good results from
maintaining plant diversity through intercropping and
maintaining weedy plot boarders. Some farmers report
attracting and feeding natural enemies of FAW through
the use of sugar water (to attract parasitoids) or fish
soup and kitchen grease (for ants).
National efforts: farmers
and researchers working
together
There is still much to be learned about how to
manage FAW sustainably in local contexts. Research
and co-creation in this regard should be conducted
on both research stations and in farmers’ fields.
Farmer Field Schools (FFS) provide an optimum
setting for farmers and researchers to work
together to test innovative solutions and learn
together. National FAW Task Forces have a role to
play in bringing together national researchers with
FFS to design and implement a joint co-creation
and research programme.
© FAO, 2019
CA3800EN/1/03.19
©FAO
Some rights reserved. This work is available
under a CC BY-NC-SA 3.0 IGO licence