Fall Armyworm (Spodoptera frugiperda) has been seen in our local area! Typically this pest is of concern mainly for turf but can also impact other crops and ornamental plants. Fall armyworm can damage landscapes seemingly overnight typically due to large numbers associated with infestations. Adults in the form of moths can ride the tropical storm currents from southern parts of the U.S, and hatched larva typically impacting our area late summer into early fall. Fall armyworm larva can be identified by the two distinctive dark stripes on either side of the larvae, as well as four black dots on the dorsal (back) side of each segment of the abdomen and a light-colored, upside-down “Y” marking on the head.

Female moths can lay eggs on different kinds of vegetation, street signs, buildings, etc. with one female moth able to lay as many as 1,000 eggs which hatch within 2-10 days. Once hatched, they drop down to turf and can rapidly feed on all foliar tissue available in massive numbers or “armies”. Multiple generations can occur within the summer timeframe. Damage to turf is distinctive with areas of defoliation and browning distinctly marked in waves and patches.

• Monitoring: By knowing what the egg masses look like, and by paying attention to new monitoring maps to track the patterns of emergence in our area, you can start mechanical means of control (scraping them off in soapy water, etc.) if you spot these eggs before they hatch. Typically we see egg masses laid in July and August in NC. 

• Pest Control: chemical control usually doesn’t work as well as other caterpillar pests (true armyworms, black cutworms, etc.) due to the fact that they are in such large numbers that it is impossible to treat all of them as well as larger larvae typically doesn’t respond as well to chemical treatment. Often times residentially, natural predators and parasitic organisms keep populations in check. For commercial sites where thresholds of damage might warrant chemical treatment, please see the listed chemicals for fall armyworm below. Note that many of the chemicals below can be toxic to beneficial insects and should be used in accordance to the label, and only if the situation warrants treatment. Reach out to your local extension office for specific information and recommendations as it pertains to your situation.

*see NC Ag Chemical Manual for more details about chemical options.

To learn more about fall armyworm, check out these resources below:

TurfFiles: Fall Armyworm in Turf Factsheet

TurfFiles: Interactive Fall Armyworm Map

Fall Armyworm in Ornamentals

UF | IFAS: Fall Armyworm Factsheet