Grasshoppers inflict substantial damage across Florida vegetable crops, citrus groves, and ornamental landscapes. This challenge is primarily driven by the Eastern Lubber Grasshopper (Romalea microptera), a native species known for its size and voracious appetite. These large insects chew foliage, causing localized pest pressure. Control strategies must account for the Eastern Lubber’s long life cycle and its resistance to certain treatments as it matures.
Identifying the Pest and Its Vulnerable Stages
Effective grasshopper management hinges on accurate identification and timing, specifically targeting the most vulnerable life stage. The Eastern Lubber Grasshopper grows into adults that can reach up to three and a half inches long. The adult stage is characterized by bright warning colors, typically a mix of yellow, orange, and black, and they are difficult to eliminate with chemical treatments.
The most effective period for control is when they are still nymphs, which begin hatching in the spring, from late February through April. Newly hatched nymphs are wingless, about one centimeter long, and usually appear entirely black with a distinctive yellow or red stripe running down their back. These young grasshoppers are often found congregating in large numbers on the tips of plants immediately after emerging from the soil. Targeting these small, slow-moving clusters of nymphs offers the best chance for population reduction.
Manual and Cultural Control Methods
Non-chemical and cultural controls are effective, especially against the slow-moving Eastern Lubber nymphs. Hand-picking is the most reliable method, particularly in the spring when the black nymphs are clustered together. Collected grasshoppers should be dropped into a container of soapy water, which quickly kills them.
Garden sanitation reduces future populations by eliminating preferred egg-laying sites. Adult female lubbers lay clusters of 30 to 50 eggs beneath the soil surface in the summer. Minimizing weeds and tall grasses, which the insects favor, limits where they deposit their egg pods. Tilling the soil in late fall or early winter mechanically disrupts these egg pods, exposing them to desiccation or predators before they hatch.
Exclusion methods are practical for protecting vegetable plants from feeding damage. Placing fine-mesh row covers or screens over vulnerable crops physically blocks the grasshoppers from accessing the foliage. While natural enemies exist, such as the loggerhead shrike, relying solely on these predators is insufficient for managing severe infestations. The Eastern Lubber’s toxic secretions make it unpalatable to most other birds and small mammals.
Targeted Chemical Treatments for Severe Infestations
When manual removal and cultural practices are not enough to manage large infestations, chemical intervention must be applied specifically to target the younger nymph stage. Effective chemical classes approved for grasshoppers include products containing the active ingredients:
- Carbaryl
- Bifenthrin
- Cyhalothrin
- Permethrin
- Esfenvalerate
- Spinosad
Application must be targeted to maximize efficacy and minimize environmental impact, focusing on the nymphs directly or the vegetation they are feeding on. Broadcast spraying should be avoided in favor of spot treatments, such as spraying the edges of gardens or vegetation surrounding the area where nymphs are emerging. Biological baits containing ingredients like Nosema locustae (Nolo Bait) can also be used, as they are ingested by the feeding grasshoppers.
Adherence to product labels is required, especially regarding pre-harvest intervals for edible plants. To protect beneficial insects, like pollinators, apply treatments during cooler times of the day when they are less active. Avoiding application during periods of high heat or when rain is expected ensures the product remains effective and does not run off into the environment.