The Eastern Lubber Grasshopper, Romalea microptera, is a striking insect known for its large size (up to 3.5 inches long) and bold coloration, commonly encountered in the southeastern United States. This species moves slowly across the landscape, earning the name “lubber.” The question of whether to eliminate this pest arises from its voracious appetite and the significant damage it can inflict on cultivated plants. This article explores the biology of the lubber grasshopper and details effective strategies for managing its population.
Identification and Assessing the Threat
The adult lubber grasshopper is easily recognized by its size and vivid warning colors, which often appear as a mix of yellow, black, and red markings. They are clumsy insects, moving mostly by walking or crawling, as their short forewings and rose-colored hind wings are incapable of sustained flight. This slow movement contrasts sharply with their destructive potential when they appear in high numbers.
The life cycle begins with nymphs hatching in early spring, often appearing in large, clustered groups. These juveniles are shiny black with a distinctive yellow or red stripe running down their back, a coloration that also serves as a warning. They are generalist feeders with a host range of over 100 plant species, and their high population density makes them a serious threat to gardens and agriculture. They can rapidly defoliate ornamental plants, vegetable crops, and citrus orchards, causing significant economic damage.
Toxicity and Natural Defenses
The lubber grasshopper’s flamboyant colors are a classic example of aposematism, a warning signal advertising its unpalatability to potential predators. The insect is chemically defended due to its diet, actively sequestering toxic compounds, specifically cardiac glycosides, from the plants they consume and storing them in their tissues. Ingesting a lubber grasshopper can be toxic or fatal to small mammals, birds, and pets that are not adapted to processing these toxins.
When threatened, the lubber employs several defenses beyond its warning colors, including hissing and spreading its wings to reveal a shocking red. It can also excrete a foul-smelling, foamy fluid from its spiracles, which contains repellent chemicals, further deterring an attack.
Effective Control Strategies
The most effective approach to control is targeting the insect during its most vulnerable stage: the nymph. Control measures taken in early spring, when the small, black nymphs first emerge and are still clustered together, yield the best results. Physical removal is highly effective for home gardeners, involving hand-picking the slow-moving nymphs and dropping them into a container of soapy water to drown them.
For larger infestations, targeted chemical control can be considered. Baits containing active ingredients like carbaryl are effective against lubbers of all stages, especially when applied along garden margins. Certain insecticides, including those with spinosad, bifenthrin, or cyhalothrin, can also be applied directly to the nymphs, which are more susceptible to chemicals than the adults.
Once lubbers reach the large adult stage, they are significantly harder to control due to their size, mobility, and chemical defenses, making many general pesticides ineffective. At this stage, physical removal, often requiring gloves, remains the most reliable method for localized problems. Preventative measures, such as mowing surrounding weedy vegetation and scouting for egg masses in the soil during the summer, can help reduce the population for the following year.