Armyworm - How to achieve sustainable food production for increased profit and well-being

Learn and understand the life cycle of one of the most invasive pests in the world, the Fall Awmyworm (FAW).

Fall Armyworm (FAW), Spodoptera frugiperda, is an insect that is native to tropical and subtropical regions of the Americas. In the absence of natural control or good management, it can cause significant damage to crops. It prefers maize, but can feed on more than 80 additional species of crops, including rice, sorghum, millet, sugarcane, vegetable crops and cotton.

In December 2019, FAO launched the pioneering USD 500 million Global Action for Fall Armyworm Control as an urgent response to the rapid spread of FAW, which threatens food security and livelihoods in many regions of the world.

The three year global initiative will take radical, direct and coordinated measures to strengthen prevention and sustainable pest control capacities at a global level. It will complement and bolster ongoing FAO activities on FAW.

United States

Source: https://aggieturf.tamu.edu/turfgrass-insects/armyworm/

Fall Armyworm: Spodoptera frugiperda Smith

Armyworms belong to the insect order Lepidoptera and family Noctuidae. Common species of armyworms include: the fall armyworm (Spodoptera frugiperda) the yellowstriped armyworm (Spodoptera ornithogalli) the beet armyworm (Spodoptera exigua) and the true armyworm (Mythimna (=Pseudaletia) unipuncta). The fall armyworm (Spodoptera frugiperda) is the most common cause of damage.

Figure 1. Fall armyworm larvae — Fall armyworm larvae

The larval stage (photo) of armyworms can cause rapid,significant loss of leaf tissue. They feed primarily on bermudagrass, ryegrass, fescue, and bluegrass, but can also be important pests of agricultural crops. The name ‘armyworm’ originates from agriculture, where infestations sometimes resemble an army as they move across large agriculture fields.

Life Cycle

Figure 3. Fall armyworm adult moth — Fall armyworm adult moth

The fall armyworm has four life stages: egg, larva, pupa, and adult. Adult moths (photo) are generally gray in color, with a 1½-inch wingspan and white underwings. Forewings are mottled with flecks of white, and males may have a triangular white spot near the wing tip, and another spot in the middle of the wing.

Fall armyworms are unusually susceptible to cold, and populations are thought to die out each winter. Infestations of fall armyworms often occur during “outbreak years”, when exceptionally high populations of the insects survive the winter.

Figure 4. Fall Armyworm Eggs — Fall Armyworm Eggs

Armyworms fly and mate at night, after which the female will lay up to 1,000 eggs in masses (photo) on suitable host plants or indiscriminate surfaces including the undersides of tree leaves or on structures (photo down).

Figure 5. Fall armyworms eggs laid on a golf course water cooler — Fall armyworms eggs laid on a golf course water cooler

After hatching, newly emerged larvae may spin a silken thread to lower themselves to the turf to feed. The earliest (1-4) instars eat relatively little leaf material, while the fourth and fifth larval stages eat over 93% of the total foliage consumed over its life span. This usually means that early damage is often overlooked, and most defoliation takes place over a relatively short period during the later development stages. Caterpillars feed throughout the day but are typically most active in the early morning and late evening hours where they can often be easily observed.

Figure 6. Inverted “Y” on head of a fall armyworm — Inverted “Y” on head of a fall armyworm

Fall armyworm caterpillars range in color from shades of brown to gray, green or yellow-green. Their most distinguishing characteristic is a whitish inverted Y between the eyes (photo), and three whitish stripes on the pronotal shield behind the head. Development from eggs to full-grown larvae often takes 2-3 weeks, at which point the larvae will burrow into the soil to pupate (Figure 7) and emerge as adults 10-14 days later when the life cycle begins again. Multiple generations occur each year, with most generations occurring in southern regions of Texas where development can often take place year round due to the warmer climate.

Damage by fall armyworm caterpillars (larvae) initially appears at the tips of the grass blades where they appear transparent due to the plant cells being eaten. If left uncontrolled, caterpillars may continue feeding, stripping tissue from turfgrass leaves and leaving brown areas adjacent to green turf.

Figure 7. Fall Armyworm Pupae — Fall Armyworm Pupae

Damage may initially resemble drought stress, but will progress to complete loss of foliage if numbers are sufficient and the turfgrass is left untreated. There may also sometimes be a distinct line between damaged and undamaged areas. Healthy and actively growing bermudagrass typically recovers after infestation and defoliation due to its aggressive rhizomatous and stoloniferous growth habit. However, newly established bunch-type grasses, such as ryegrass or fescue, may be stunted or killed by armyworm feeding.

Dr. Eileen Cullen, University of Wisconsin Extension Entomologist, takes you into the field to show you when to scout and how to manage key pests of Wisconsin field crops. For more information, visit http://www.entomology.wisc.edu/cullenlab and http://ipcm.wisc.edu

Control Recommendations

While scouting for damage is important for all insects, careful inspection is especially important for this pest due to the rapid nature of its destructive feeding. If armyworms are present in turfgrasses in large numbers, it is important to treat as soon as possible to avoid further injury. There are several active ingredients that are effective in controlling fall armyworms, but many variations exist in formulation, use site, applicator requirements, etc. As always, be sure to follow the product label for specific instructions on timing, use rate, and application methods.

If left untreated, fall armyworms (Spodoptera frugiperda) can destroy a pasture or field of crops in a very short time. James Locke, soils and crops consultant for the Noble Foundation, shows you how to identify the fall armyworm caterpillar, signs of damage that you will see on grass or crops and available chemical treatments to control the pest. Additional fall armyworm information: “The Fall Armyworm: Pest of Pasture and Hay” by Allen Knutson, Professor and Extension Entomologist Texas A&M AgriLife http://bit.ly/FallArmywormFacts

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Photo courtesy of Lorine Auma / https://www.gofundme.com/f/nyathuongweno-community-permaculture-project-kenya

Global Action for Fall Armyworm Control

http://www.fao.org/fall-armyworm/en/

In December 2019, FAO launched the pioneering Global Action for Fall Armyworm Control as an urgent response to the rapid spread of FAW. The three-year global initiative will take radical, direct and coordinated measures to strengthen prevention and sustainable pest control capacities at a global level. It will complement and bolster ongoing FAO activities on FAW.The Global Action is establishing a global coordination mechanism for an open and collaborative dialogue towards science-based solutions. It is also supporting the establishment of National Task Forces on FAW, and the mobilization of resources for applied research geared towards practical and efficient solutions.

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Videos

Australia

2.03.2021 Farmers say fall armyworm, the ‘coronavirus of agriculture’, could force up food prices | ABC News

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Outlines fall armyworm lifecycle, the dangers of chemical pesticides, and the biological control methods for the control of the pest.

Fall Army Worm (Spodoptera frugiperda) is causing sever losses in several crops, especially in Maize, affecting food security in many countries. Pesticide sales-men are enjoying and selling off pesticides, no matter if they’re effective or not, if dangerous or not, and controls are minimum. Unfortunately these sprayings are killing their natural enemies. An adult moth can fly up to 100km per night; in her life time lays over 1,500 eggs feeding on over 80 known crops here in Africa. This pest’s amazing abilities makes it very difficult to control. Preparing and applying bait with local ingredients is the best option for small scale farmers. Watch the video and apply it on your maize and in 8 hours, the worms will be dead while their natural enemies will survive.

Ghana – Harnessing Local Capacity To Combat Fall armyworm; GAEC Make Strides

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Neem Plant – a safe, effective herbicide that can be used to combat armyworm
https://www.cleanairgardening.com/neem-plant/