How to Control Fall Armyworms in South Florida

Fall armyworms are destructive causing severe damage to beautiful turfgrass and crops, some crops that are affected by these worms are cotton, vegetables, soybean, corn,  rice,  peanuts, onion, beets, sugarcane,  millet, cabbage, sorghum, alfalfa, etc..

Fall armyworms are mostly active from late summer through late fall, feeding both during day hours and nighttime but are most active early in the morning or late in the evening. Many homeowners watch in horror as their edible crops are destroyed or their beautiful lawns are reduced from healthy green to brown.

During feeding time, armyworms will assemble in a large population, consuming all of the plant’s foliar or leaf tissues. At the first sign of fall armyworms or their damage control measures should be taken to reduce and eliminate their population.

Fall Armyworm Adult Moth Identification

The adult moth is about 16-18 mm in length with a wing span of 34-40 mm, the forewings of this month are brown to grey. The hind wings are creamed-colored.

Fall Armyworm Caterpillar Identification and Lifecycle

The female lays about 1000 eggs in masses of 50 to several hundred, which are pale yellow and are laid on the plant’s leaves. The eggs are then covered with a silk-furry substance. After the eggs hatch the larvae begin feeding. Newly hatched larvae are light green with a dark head, and as the worm matures, they change color from brown to grey. Within 2-3 weeks the larvae dig into the soil to pupate. About 2 weeks later a new generation of moths emerges. The lifecycle of the fall armyworm from larvae to adult is about 10-21 days.

Fall Armyworm Crop Damage

Fall armyworms feed on the leaves, stems, and reproductive parts of over 100 species of plants causing severe damage to crops and cultivated grasses. The damages that fall armyworms cause globally are estimated to be as much as US$2 Billion per year.

Fall Armyworm Crop Management

Before using pesticides on crops ensure that it’s safe to treat food crops along with the listed pests therefore it’s important first to read and follow the manufacturer’s directions for the best results. Fall armyworms are resistant to many pesticides therefore treating these worms with the wrong pesticide will not have an effect but will kill off natural predators of the fall armyworm and will eliminate other beneficial insects including pollinators.

Best management practices are a great way to grow healthy plants for example ensure that the soil you’re using is healthy because healthy soil will encourage healthy plants that are resistant to pests attack and recovery quickly from damage.

Push-pull farming is another method that is used to control fall armyworms, this technique works by interplanting or companion planting around food crops to protect against garden pests including fall armyworms.  For example garlic, marigolds, chrysanthemums, etc.. By diversifying you introduce natural enemies which is another benefit of companion planting. The use of compost or mulching increases soil biodiversity creating a habitat for small animals that prey on the fall armyworm. An insecticide that is effective in controlling fall armyworms is neem oil.  Bacillus thuringiensis can be used as well to bring control. Pyrethroids and Spinosad are effective against fall armyworm management. The ideal time to control fall armyworm larvae with insecticides is when they are young because at this stage they’re more susceptible.

Fall Armyworm Turfgrass Damage and Management

The fall armyworms damage lawns by feeding on or chewing the grass tissues, these worms are most active on grass turf during the early morning hours, late afternoon, or early evening. Fall armyworms are more obvious during the day on tall lawn grasses that are unmowed. The larvae can be found deep in lawn turf that is mowed regularly during the warmer hours of the day. If you discover that birds and wasps have suddenly taken an interest in your lawn may be a sure sign that these worms are present and being used as a food source.

To further test your lawn for fall armyworms look for areas where wasps and birds are congregating, pour a mixture of soapy water into this area, if armyworms are present they will come to the surface. The soapy water test will also reveal if you also have sod webworms, chinch bugs, or mole crickets.

Natural predators or parasites of fall armyworms are nematodes, entomopathogenic fungi, bacteria, parasitoids, and viruses. Also, another method is Bacillus thuringiensis (Bt) or neem oil. Insecticides that are labeled to control fall armyworms will bring good results, however before using insecticides read and follow the manufacturer’s directions for the best results.

Cultural Practices

Cultural practices are a great way to encourage plants that can survive or be resistant to fall armyworms.

• Make sure that your garden is neat and clean at all times, the removal of garden debris and weeds will manage and discourage garden pests including the fall armyworm.
• Always inspect your garden regularly for garden pests, rodents, and the fall armyworm.
• Take quick action if pest activity is discovered.

Call in the Professional

Fall armyworms can be difficult to control so if you don’t have the time or if you would rather have someone else deal with this issue then call in a professional pest control or landscape company to do the job for you.

Conclusion

The control of fall armyworms is necessary and must not be overlooked because of their destructive behavior,  fall armyworms can be managed by following this guide. Join the many homeowners who are having much success by implementing these methods. You will be glad that you did, why should you settle for the fall armyworm destruction to your beautiful lawn turf or robbing you of your crops before you can reap a harvest?