Look Sharp For Granulate Cutworms
October 24, 2013 
Pest Specs
Granulate cutworm, Feltia subterranea Fabricius, commonly damage vegetable seedlings by cutting off them off at the soil surface. They also can damage older plants by feeding on foliage, and often injure tomato, watermelon, and eggplant by feeding on or burrowing into the fruit.
Identification
Due to its surface-feeding behavior, granulate cutworms are sometimes a major component of the “rindworm” complex affecting cucurbit fruit especially when fruit are in contact with soil. Granulate cutworm feeds on a wide range of vegetables and agronomic crops as well a number of weedy species. This cutworm is grayish to reddish-brown in color with each abdominal segment bearing dull yellowish oblique markings. A weak gray line occurs laterally below the spiracles, accompanied by spots of white or yellow. The head is yellowish to brownish in color.
The moth is medium in size. The color of the forewing varies considerably in its shades of brown and gray and bears distinct bean-shaped and round spots centrally, which are linked by a small but sharply defined black bar. The hind wings are white, but dusky marginally and along the veins.
Survival And Spread
The granulate cutworm is the most commonly occurring cutworm in Florida. It is nocturnal and often is overlooked so its activities and damage may not be fully appreciated. This species is native to the western hemisphere and is tropical in distribution. In the U.S., it occurs most frequently in the southernmost states, but ranges further north. The granulate cutworm is the most important cutworm pest of vegetables in the Gulf Coast region and also is important in California. Granulate cutworms can be found throughout the year in the south. Adults, eggs, and larvae have been collected during all months in Louisiana and Florida. In Florida, adults are most abundant from April to June but breed almost continuously. The complete life cycle normally requires 50 to 70 days depending on weather.
Females produce 800 to 1,600 eggs, which are deposited singly or in small clusters on the upper surface of foliage. The eggs are rounded and bear distinctive ridges.
Young larvae initially remain on the foliage during both day and night. But after a few days, they begin to hide beneath plant debris or soil during the day, feeding only at night. The number of instars varies from five to seven, but six instars is most common.
Pupae are dark brown or mahogany in color and pupation occurs in the soil.
Management Methods
Moth populations can be monitored with black light traps. Larvae can be controlled by application of insecticides delivered as liquid, granule, or bait formulations. Baits, particularly bran-based baits, seem most effective.
Considering the importance of this cutworm in southern states, little is known about natural enemies. Several wasps and fly parasitoids are known to parasitize granulate cutworm. A granulosis virus also is known, but the importance of natural enemies is uncertain.
Consult UF/IFAS recommendations for currently labeled insecticides for cutworm control in Florida vegetables.
Subscribe Today For
