Louisiana Fall & Winter Vegetable Garden Insects

Tomatoes are one fall vegetable that is grown in Louisiana.

Louisiana's climate, which consists of USDA plant hardiness zones 8 and 9, allows gardeners to grow some vegetables year-round. The mild fall and winter weather is ideal for crops like broccoli, cabbage, spinach, Brussels sprouts and lettuce. However, the temperate climate also allows some common vegetable garden pests to continue to thrive in the fall and winter.

Worms

The horn worm can damage tomato crops.

Worms like fruit worms, horn worms and pin worms damage vegetable crops by eating away at foliage and boring into vegetables. In Louisiana fall gardens, horn worms mainly affect the tomato crops. Horn worms are the larvae of the hummingbird moth (also known as hawk or sphinx moth). The horn worm can be controlled by hand picking the worm from the plant and destroying it, turning the earth between crops and by the parasitic wasp, a beneficial parasite that lays eggs on the back of the horn worm. For larger crops, the Integrated Pest Management Center recommends weekly spraying of a pesticide such as permethrin.

Aphids

There are many varieties and colors of aphids.

Aphids feed on the foliage and stems of vegetables. There are many colors and varieties of aphids, from green, red, brown and yellow to winged, wingless, woolly and waxy. When they appear in vegetable gardens in large numbers, they can yellow and distort leaves, stunt growth and cause a sooty mold fungus to appear on foliage. Aphids can be controlled by natural predators like earwigs and Asian lady beetles. Daily application of insecticidal soap or neem oil can also kill aphids. Insecticides can be used, but it is important to note they may also eliminate beneficial insects as well.

Earwigs

Earwigs can be beneficial in a fall and winter garden.

Earwigs are small insects that can measure between 10 to 26 mm in length. A nocturnal insect, earwigs can be both beneficial and detrimental to fall and winter gardens. Earwigs eat aphids, one of the most common and destructive garden pests. Earwigs may cause light damage to foliage in vegetable gardens if there are not enough aphids to satisfy their diet.

Sweet Potato Weevil

Sweet potato crops can be virtually destroyed by the sweet potato weevil.

The sweet potato weevil has been a garden pest in Louisiana since 1875. A colorful black, blue and red insect with antennae, the sweet potato weevil can live more than 200 days. As larvae, these weevils feed on the tubers and vines of the sweet potato plant and can destroy as much as 97 percent of a sweet potato crop.

Asian Lady Beetle

Asian lady beetles are beneficial in the Louisiana vegetable garden.

Louisiana was the first state in the United States to begin using the multicolored Asian lady beetle as a beneficial insect in 1988. Like earwigs, these insects come with both positive and negative aspects. Asian lady beetles provide a natural way to rein in populations of pests like aphids and scale. However, while they are beneficial in the garden, they often also invade homes and other buildings during the winter. Since they emit a staining, malodorous fluid when threatened or damaged, they are unpleasant in the home.

References

• USDA Hardiness Zone Map: Louisiana Area
• Southern States: Planting Fall and Winter Vegetables
• Integrated Pest Management Center: Crop Profile
• Colorado State Extension: Tomato/Tobacco Hornworms
• University of California at Davis: Aphids Management Guidelines