A LARGE GRASSHOPPER 7 



Class: Tracheata. Division: Insecta. Order: Orthoptera 

 A LARGE GRASSHOPPER 



Observe the shape, color, and external anatomy of the animaL 

 Note the long, vermiform body and the large head. The body, as 

 in all insects, is made up of a number of serially arranged seg- 

 ments, called somites, or metameres, which fall into two divi- 

 sions, the thorax and the abdomen. The head is unsegmented, 

 being composed of a number of completely fused somites, and 

 bears upon its dorsal and anterior surface a pair of long, jointed 

 feelers, or antennae, which are important sense organs, a pair of 

 large compound eyes, and three small, dotlike eyes, called ocelli, 

 which it may be necessary to look for with a hand lens ; on its 

 ventral side are the mouth parts, the organs with which it tastes, 

 grasps, and masticates its food. Examine these mouth parts with 

 a hand lens. Observe the long, broad upper lip and pass a needle 

 under its ventral edge. Back of the upper lip will be seen the 

 strong mandibles, and by pressing these to the right and left the 

 two remaining pairs of mouth parts, the maxillae and the under 

 lip, will be seen. Note the two pairs of jointed palps belonging to 

 them, which are probably organs of taste. These parts will all be 

 studied later in detail. 



The thorax is made up of three somites, which are called the 

 prothorax, the mesothorax, and the metathorax. Notice that the 

 thorax is not separated from the abdomen by a constriction, as 

 it is in the wasp, but that it may be easily distinguished from the 

 abdomen by its greater diameter. The prothorax is movable, as in 

 the beetle, and its dorsal and lateral surfaces are covered by a 

 large shield. On the ventral side of the prothorax, between the 

 prothoracic legs, is, in many grasshoppers, a short projection. 

 The mesothorax and metathorax are united immovably with the 

 abdomen and are covered by the two pairs of wings. The anterior, 

 or mesothoracic, wings are parchment-like and are not functional 

 in flying, but, like the wing-covers of beetles, are held out at right 

 angles to the body during flight. The metathoracic wings are 

 membranous and when at rest are folded longitudinally like a fan 



