Eggplant Pest Management
While citrus may come to mind when people think of crops in Florida, the state was ranked second nationally in annual eggplant production.
With eggplant production happening throughout Florida (southeastern Florida being the main production region), it’s important for farmers to familiarize themselves with pests that could damage their crops.
American Serpentine Leafminer
American serpentine leafminers feed on a number of crops, including eggplants, and they are present throughout the growing season. Adults (small black and yellow flies) deposit their eggs in leaf tissue. These eggs then hatch within a few days and feed inside the leaf until they mature and drop to the soil.
Although parasitic wasps can manage leafminers, these wasps can be killed by spraying non-selective insecticides (which can lead to a large outbreak of leafminers).
Aphids typically appear at the end of the season when growers aren’t actively spraying. Although aphids are minor pests, they can affect eggplant production. These insects damage a plant by injecting their sharp, hollow mouthparts into its tissue and sucking out the plant’s juices. Aphids can also spread plant viruses.
Many beneficial insects feed on aphids, including ladybugs, aphid lions and hover flies. If a sufficient number of these natural enemies are present, then they can control aphid populations before the aphids expand. One well-delivered insecticide spray can also kill all aphids on a crop until winged-aphids migrate.
Beet (and occasionally southern) armyworms are minor eggplant pests throughout the growing season—peaking in the state from June to September. Adult armyworm moths lay eggs that hatch, and the larvae collect on the underside of plants. The larvae then scrape away everything but the clear cuticle, which gives leaves a “window-pane” look. Older armyworm larvae disperse and may enter the fruit of eggplants.
These small insects attack a number of crops, including eggplant. Females lay their eggs on plant tissues, and the plant is damaged by both adult and hatched larvae feeding on the leaves, steams, flowers and fruit. (In eggplants, thrips are typically more abundant on leaves.) Fruit damage may result in economic crop loss.
Melon thrips are resistant to many insecticides. Using broad-spectrum insecticides may kill natural enemies, which could increase melon thrip populations.
Silverleaf whitefly is a significant pest of eggplants and several other crops in Florida. Although these insects are most abundant between December and May, they may be seen throughout the season. Nymphs, which are found on the underside of leaves, pierce plants with their mouthparts and suck the plants’ juices.
Field hygiene is important when managing whitefly populations. Hygiene practices include establishing a crop-free period for a minimum of two months during the summer (preferably from mid-June to mid-August) along with the use of a crop destruction technique. Growers should also remember not to apply insecticides to weeds on filed perimeters, as this could kill the whitefly’s natural enemies.
These moth larvae are serious pests in warmer climates where they feed on leaves, stems and fruit. While the initial injury (a small leaf mine) is barely noticeable, later injury (leaf folding) caused by older larvae is more apparent. Leaf folding can hinder an insecticide’s effectiveness, and other damage may then result from infections.
Growers often see pinworms when they use non-selective insecticides, which reduce the beneficial insect populations.
Adapted and excerpted from:
Mark A. Mossler and O. Norman Nesheim, “Florida Crop/Pest Management Profile: Eggplant” (CIR1264), UF/IFAS Department of Agronomy (rev. 09/2012).