Exercise 3: Internal Anatomy of the Lubber Grasshopper, Romalea

Laboratory Specimens The eastern lubber grasshopper, Romalea guttata, is often used as the introduction to insect anatomy. Romalea is a large insect, reaching 50 to 75 mm in length, and is easily dissected. It is a good example of general, relatively unspecialized insect anatomy. Romalea is best studied using anesthetized living, or freshly sacrificed specimens. Preserved animals are much less satisfactory. Unfortunately, the life cycle is such that living adults are not usually available during the academic year when they are needed. These instructions are based on unpreserved specimens and references to color usually do not apply to preserved material. The lubber grasshoppers (Romaleidae), are mostly found in Central and South America but one species, R. guttata occurs in the eastern United States. This species ranges from Tennessee and the Carolinas south to Florida and Louisiana. Within its range its distribution is patchy but where present it may be very common in the summer. Romalea guttata is flightless and has reduced wings, so if the specimens provided have complete, functional wings, they are not the eastern lubber grasshopper. Lubbers are herbivores with chewing mouthparts. Like other orthopterans they have hemimetabolous development. Eggs diapause over winter and hatch in April into miniature glossy black grasshoppers with orange, yellow, or red markings, with a mid-dorsal stripe. Juveniles undergo a series of molts during the summer and in July undergo the final molt and become a winged adult. The adult is gray, black, and yellow, with pink on the forewings. The hind wings are hot pink with a black border but are usually hidden. Females (about 70 mm) are larger than males (about 55 mm) and, of course, have a short ovipositor which is lacking in males.