Referred to as Tomato Fruitworm when found on tomato.
Color quite variable; may be green, brown, or pink. Light and dark stripes along sides and back. Up to 1 and 3/4 inches long. When insect occurs on tomatoes, it is called the tomato fruitworm.
Sweet corn, okra, beans, broccoli and tomato.
Attacks beans in the fall, eats holes in pods. Damage is worst in warm, coastal areas. Early in the season feeds on central shoot of sweet corn; later burrows through silk and feeds on kernels near tip of ear.
Throughout United States.
Overwintering occurs in the pupal stage in soil. Moths emerge in late spring and deposit eggs singly on corn seedlings; later generations lay eggs in the developing corn silk. Each female can lay up to 3000 eggs, which hatch in two to ten days. When larvae emerge after two to five days, they feed on whorls and developing grains. Corn earworm larvae are cannibals and will eat one another, until often, only one larva remains per ear. After feeding for two to four weeks and developing through five or six instars, mature larvae enter the soil to pupate. During summer months pupation occurs in 10-25 days. Multiple generations occur annually in Virginia.
The following thresholds are for sweetcorn. Blacklight or pheromone traps are used for monitoring populations of corn earworm in the field. Traps should be in field before first tassles develop. Monitor traps on a daily basis and keep annual records.
|
# of corn earworm moths caught per night in blacklight traps |
# of corn earworm moths caught per night in pheromone traps |
|
|
less than 5 |
less than 10 |
treatment not warranted |
|
greater than 5 |
greater than 10 |
treatment warranted; if silks present apply insecticide & treat every 3-5 days until silks brown |
|
greater than 25 |
greater than 100 |
treat if silks present; re-treat every 3-4 days while catches are high until silks brown |
|
greater than 100 |
greater than 500 |
treat every 2-3 days with most effective insecticide at the highest labelled rate while catches are high until silks brown |
For small gardens, hand-pick and destroy wormy fruit and damaged pods. In corn, break off and discard worm infested tips of ears. Disk or rototill plants and culls immediately after harvest.
Bacillus thuringiensis (Bt) should provide enough control for garden vegetables such as tomatoes, beans, and lettuce. For earworm control on sweet corn, apply 20 drops of mineral oil with a medicine dropper to silks inside tip of ear after silks have wilted (3 to 7 days after silks first appear). Tiny parasitic Trichogramma and Hyposter wasps are important natural enemies.
Treat with a registered insecticide.
For sweet corn: Apply at 2-3 day intervals when silking. Caution: Honeybees are necessary for good fruit set; insecticides are toxic to bees. Apply in evening when fewer bees are working.
For beans: Treat when pods are 1 inch long and weekly thereafter.
For tomato: Treat every 5-7 days when fruit begins to set. Continue as long as fruit is present if needed.
Because pesticide labels can change rapidly, you should read the label directions carefully before buying and using any pesticides. Regardless of the information provided here, you should always follow the latest product label when using any pesticide. If you have any doubt, please contact your local Extension agent or pesticide dealer for the latest information on pesticide label changes.
Disclaimer: Commercial products named on this site are for informational purposes only. Virginia Cooperative Extension does not endorse these products and does not intend discrimination against other products which also may be suitable.
Foster, Rick and Brian Flood. 1995. Vegetable Insect Management, Meister Publishing Company, Willoughby, Ohio. p. 35.
Prepared by Alexandra Spring and Eric Day (Modified from a publication by the USDA)