Lubber grasshoppers, such as the Eastern lubber grasshopper (Romalea microptera), are large, distinctive insects commonly found in the southeastern United States. These flightless grasshoppers, which can grow up to 3.5 inches long, are known for their vibrant yellow, black, and orange coloration. Their striking appearance serves as a visual signal, hinting at their unique characteristics. Despite their size and prevalence, few animals prey on them, making them a challenging meal.
Animals That Prey on Lubber Grasshoppers
A few specialized predators have developed methods to overcome their defenses. The Loggerhead Shrike (Lanius ludovicianus) is a notable example. These “butcher birds” lack strong talons and instead impale their prey on thorns, barbed wire, or other sharp objects. For lubber grasshoppers, shrikes will decapitate them and then impale the insects, leaving them exposed to the sun for a few days to allow the toxins to degrade. Shrikes also selectively consume only the head and abdomen, discarding the toxic thorax.
Some lizards and birds also learn to avoid lubbers due to their defensive secretions. Naive vertebrates, particularly birds and small mammals, can become ill or die after consuming a lubber. Despite this, certain species may occasionally attempt to prey on them. For instance, some studies indicate that even young lubber nymphs, which produce fewer chemical defenses, are still avoided by lizards.
Other potential predators include certain parasitoids and entomopathogens, which are less affected by the lubber’s chemical defenses compared to vertebrate predators. These organisms can still impact lubber populations. However, the exact range of these natural enemies is not extensively documented.
Why Lubber Grasshoppers Are Difficult Prey
Lubber grasshoppers possess a suite of defenses that deter most potential predators. Their bright, contrasting colors serve as a clear warning signal, a phenomenon known as aposematic coloration. This visual advertisement communicates to predators that the grasshopper is unpalatable or toxic.
Beyond their warning colors, lubbers sequester toxic compounds from the plants they consume. These chemicals, while harmless to the grasshoppers themselves, are poisonous to many animals and can cause illness or death if ingested. The specific toxins can vary depending on the lubber’s diet, making it difficult for predators to adapt to a consistent chemical defense.
When threatened, lubber grasshoppers employ several behavioral defenses. They can produce a loud hissing sound by expelling air from their spiracles and secrete a foul-smelling, irritating foam from openings on their bodies. They may also regurgitate a dark brown, noxious fluid, often called “tobacco spit,” which consists of recently consumed plant material and semi-toxic compounds. Additionally, their sturdy chitinous exoskeleton and spiny legs provide a physical deterrent against attackers.