The Eastern Lubber Grasshopper: Hard to Miss, But Only an Occasional Pest
Many entomologists, and plenty of biology students who have pursued other callings, know the eastern lubber grasshopper (Romalea microptera) inside and out—literally, because there’s a good chance it was the first insect they dissected in a school lab.
Throughout the southeastern United States, it’s also a common sight in swamps, woodlands, fields, and ditches. And, for the completely uninitiated, the eastern lubber aligns closely with what might be deemed a “classic” image of a grasshopper.
Even Timothy Schowalter, Ph.D., professor of entomology at the Louisiana State University Agricultural Center, distinctly remembers catching his first R. microptera as a “young, budding entomologist” at just 10 years old, while on a family vacation.
“I collected a specimen at Bellingrath Gardens in Mobile, Alabama. I was somewhat frightened but also fascinated by its hissing, foaming, and scratching. My mother, who was very supportive of my interest in nature, accommodated me by carrying it in her hand most of the way through the gardens,” he says. “I still have that specimen.”
Today, Schowalter often gets calls at the LSU Ag Center from members of the public asking whether the eastern lubber is dangerous to humans or plants. Given its size (females can reach 3.5 inches long), its often bold coloration, and those ostentatious defensive behaviors, that concern is perhaps not surprising. But Schowalter assures callers that the eastern lubber grasshopper is harmless to humans, and in fact it’s only rarely a pest of concern to plants.
But that volume of questions is enough that Schowalter sought to assemble a profile of the eastern lubber grasshopper in the Journal of Integrated Pest Management, published earlier this month, to allay concerns and offer IPM pros a handy outline of R. microptera‘s biology and management options, if and when necessary.
In its adult stage, the eastern lubber grasshopper’s color pattern serves as a warning to predators, though the particular colors vary across its range: mostly yellowish in eastern areas but mostly black with red or yellow markings in western areas, and a blend of the two in regions between. Should a predator still get too close, the eastern lubber issues further warnings: spreading its wings, hissing by expelling air from its spiracles, secreting a foul-smelling froth, and vomiting.
“The bottom line is that this grasshopper presents a really frightening appearance, but contrary to the concern expressed by many callers, its defenses are targeted to insectivorous vertebrates, and it is harmless to humans,” Schowalter says.
Eastern lubbers are gregarious and feed on a wide range of plants. Among agricultural settings, young citrus orchards can be vulnerable to damage from the grasshoppers; elsewhere, they pose more cosmetic damage to landscape plants or gardens in residential areas near the species’ natural habitats.
Because of the eastern lubber’s size, most commonly used chemical insecticides aren’t effective, Schowalter says, and so other management methods are more useful: mowing bordering vegetation, choosing ornamental plants that lubbers tend not to feed on, and even hand-picking them from plants. In orchards near lubber habitats, insecticide baits can be effective, and an insecticide spray around the border can prevent the flightless grasshoppers from entering.
For its own defenses, the eastern lubber grasshopper sequesters and synthesizes chemicals from the plants it eats, turning them into toxic secretions that predators learn quickly to avoid. The monarch butterfly is a primary example of this capability, but Schowalter says the eastern lubber grasshopper “displays a much wider variety of chemical sequestration.”
Schowalter might not have known about chemical sequestration when he collected his first eastern lubber grasshopper at age 10, but the species continues to fascinate: “Its similarity to the black and red horse lubber, Taeniopoda eques, which occurs in Arizona and south to Central America, begs for molecular analysis,” he adds, “to see what factors have influenced the cline in coloration and if the eastern lubber and horse lubber might at one time have represented continuation of this cline westward but become isolated and distinct as a result of some barrier between eastern Texas and Arizona.”
Journal of Integrated Pest Management