The lubber grasshopper (Romalea microptera or Romalea guttata) is a large, slow-moving insect notorious for its destructive feeding habits in the southeastern United States. These pests can grow up to three inches long, making them highly visible and capable of causing significant defoliation to vegetable gardens, citrus groves, and ornamental plants. Successfully managing this pest depends on understanding its life cycle and employing specific, targeted control methods. This article provides strategies for eliminating an infestation and preventing future occurrences.
Identifying the Pest and Optimal Timing
Correct identification is the first step toward effective control, as the lubber grasshopper undergoes a dramatic color change as it matures. Newly hatched nymphs are recognizable by their clustered behavior and their color, which is predominantly black with a distinct red, yellow, or orange stripe running down their backs. These young insects are wingless and tend to feed in large, concentrated groups on the first plants they encounter.
The adult grasshoppers are much larger and feature bright warning colors, typically a combination of yellow, orange, or tawny with black markings. They are clumsy walkers and are flightless, possessing only short wings, which makes them easier targets than flying grasshopper species. Timing is paramount for management because the nymphs are most vulnerable and easiest to control when they first hatch in early spring, generally from late March through April. Intervention at this stage is significantly more effective than attempting to manage the highly resistant adults later in the season.
Physical and Manual Removal Strategies
For small to moderate infestations, or for those who prefer non-chemical approaches, physical removal is a highly effective method, especially against clustered nymphs. Since lubbers are slow and tend to congregate, they can be easily picked off plants by hand or swept into a collection device. It is important to wear gloves during this process, as the lubber grasshopper will excrete a foul-smelling, noxious foam and a dark, staining liquid when handled.
The most practical method for disposal involves submerging the collected insects in a container filled with soapy water. A solution of about 25% liquid dish detergent mixed with 75% water will quickly drown the lubbers. For larger numbers, a shop vacuum can be used to quickly suck up groups of nymphs. Simple physical barriers, such as netting or row covers, can also be placed over highly vulnerable plants to prevent the walking nymphs from reaching the foliage.
Targeted Pesticide Application
For widespread or heavy infestations where manual removal is impractical, targeted pesticide application may be necessary, focusing strictly on the vulnerable nymph stage. Adult lubber grasshoppers are difficult to kill with chemical sprays due to their large size, tough exoskeleton, and ability to detoxify many common insecticides. Insecticide application must be a direct hit, meaning the chemical must contact the insect itself rather than relying on residue on the plant foliage.
Active ingredients that have proven effective against lubber nymphs include carbaryl, bifenthrin, cyhalothrin, permethrin, esfenvalerate, and spinosad. Carbaryl is also available in a granular bait formulation that can be applied to the ground around garden margins or high-traffic areas. This bait is effective against all stages, though it should be used cautiously and according to label instructions, especially near food crops or areas frequented by pets. Always read the product label carefully, as non-selective pesticides can pose a risk to beneficial insects.
Preventing Future Infestations
Long-term management requires disrupting the lubber grasshopper’s reproductive cycle to reduce the population in the following year. Female lubbers lay their eggs in the ground, typically in clusters of 30 to 50 eggs per pod, which overwinter in the soil before hatching in the spring. Tilling or deep cultivation of the soil in late fall or during the winter months exposes these egg pods to harsh weather and predators, which significantly reduces the number of nymphs that will emerge.
Habitat modification plays a substantial role in discouraging their presence. Lubbers prefer to lay eggs and reside in tall grass, weedy areas, and brush piles, so keeping the lawn consistently mowed and clearing away organic debris and weeds removes their preferred nesting sites. Maintaining a clean landscape and disturbing the soil where they are known to lay eggs breaks the cycle and minimizes the chance of a recurrence.