The robust femur has several surfaces and ridges that have been given names for easy reference Fig. The long and slender tibia bears along its posterior edges a double row of spines and distally two pairs of articulated spurs or calcars.
The number of spines and the length of calcars vary among species. The inner medial area of the femur may have a longitudinal ridge bearing a series of stridulatory pegs.
Up and down movements of the hindlegs cause the pegs to scrape against a raised vein on each tegmen, which produces a song or signal peculiar to that species of grasshopper. The two pairs of grasshopper wings differ in shape, structure, and function Fig. The front pair, or tegmina , are leathery and narrow with the sides nearly parallel. The hind wings are membranous and fan-shaped. Compared with the tegmina, the hind pair contribute three times as much to flight lift.
Both pairs afford diagnostic characters that aid in the identification of species. The wing veins , sclerotized tubes providing strength to the wings, vary greatly in thickness. The tegmina vary from immaculate to distinctly spotted or marked. The hindwings of grasshoppers are usually hyaline. Members of one subfamily, the Oedipodinae or bandwinged grasshoppers, have wings with a dark submarginal band and have the disk colored. Segment I is firmly fused with the metathorax and contains the auditory organ with its eardrum cover, the tympanum Fig.
Each segment has a sclerotized tergum that covers not only the top but also the sides of the abdomen. A sclerotized sternum covers the bottom. Pliable membranes separate the terga from the sterna and with the intersegmental membranes allow the abdomen much flexibility, a requirement for respiratory movements, copulation, and oviposition.
The terminal segments of the abdomen are reduced and modified to bear the external reproductive organs, the genitalia, and the associated structures Fig. These structures offer the most reliable taxonomic characters for separating spurthroated grasshoppers. Structures of the male are more distinctive than those of the female. The prominent paired cerci are usually conical, but in the males of some genera, e.
Melanoplus , they have characteristic sizes and shapes. Likewise, the furcula , a pair of projections from the posterior edge of tergum X of males, differs in size and shape.
The epiproct or supraanal plate , although roughly triangular, varies sufficiently in shape and rugosity to be taxonomically useful. The variations in shape and protuberances of the subgenital plate are also useful in identification. These structures are easily seen with a pocket magnifier of 10x magnification.
A few distinctive structures, such as the lobes of the aedeagus , require the use of a stereomicroscope magnification of 50x and greater for clear identification. The valves of the ovipositor are sometimes useful in separating species Fig 1. The dorsal and ventral pair of valves have various shapes and denticulations. The middle pair of valves are small and hidden. The sclerotized integument of the abdomen varies in color, patterns, and texture among species and sometimes affords distinguishing taxonomic characters.
University Ave. Visit Campus. Download Viewbook. Give to UW. Entomology Home. Field Guide to Common Western Grasshoppers. Phone: Email: insectid uwyo. Grasshoppers of Wyoming and the West Entomology. Detailed External Anatomy Head Thorax Legs Wings Abdomen Genitalia Nymphal Characters Field Guide Contents Head The head of the grasshopper is a hard capsule that contains large muscles, which operate the chewing mouthparts, and the brain and subesophageal ganglion, which serve as the main centers of the nervous system.
Figure 2. Diagram of three forms of grasshopper antennae: filiform or threadlike, ensiform or sword-shaped, and clavate or club shaped HEAD Figure 3. Grasshopper head, front, side, and top views. Modeled after Trimerotropis pallidipennis Burmeister. List of Grasshopper Parts Field Guide Contents Thorax The thorax, locomotion center of the grass-hopper, is a stout, boxlike structure consisting of three fused segments: the prothorax , mesothorax , and metathorax.
Grasshopper pronotum, side and top views. Modeled after Trimerotropis pallidpennis Burmeister. Sternum of thorax, bottom view. They have six jointed legs, two pairs of wings and two antennae.
Their body is covered with a hard exoskeleton. Most grasshoppers are green, brown, or olive-green. The biggest Grasshoppers are about 4. Their legs are long hind legs that are used for hopping and jumping. The short front legs are used to hold prey and to walk. For a more indepth look at the anatomy of a grasshoppers body, click the image.
For an indepth look at the head of a grasshopper, click the image. Abdomen — the segmented tail area of a grasshopper, which contains the heart, reproductive organs, and most of the digestive system.
Antennae — like all insects, grasshoppers have 2 segmented antennae that sense touch and odours. Compound eye — grasshoppers have 2 faceted eyes made up of many hexagonal lenses.
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