382 



APPLIED BIOLOGY 



How many parts in a leg ? Are they similar ? Observe the hooks 

 and pads on the feet these are used in clinging when the animal is 

 at rest. Notice how the legs are adapted for jumping. 



Head. The head is attached to the thorax by a soft neck. 

 Examine the large eyes with a hand-lens, and with a microscope ex- 

 amine a slice from one of the eyes. Like the paired eyes of the crus- 

 taceans, those of insects are compound eyes. 

 Also, several bead-like simple eyes (ocelli) are 

 in many insects situated on the head between 

 the compound eyes (use hand-lens). Exam- 

 ine the long slender feelers (antennae) with 

 hand-lens. Examine the mouth-parts : upper 

 lip (labrum) ; lower lip (second maxillae, la- 

 bium) ; first maxillae, and jaws (mandibles) 

 between the lips ; and a tongue-like organ 

 within the mouth. 



Make enlarged drawings of a grasshopper : 

 (1) in side view with wings in closed or rest- 

 ing position, (2) of front view of head, (3) of 

 a leg, (4) of side view of abdomen. 



Examine young grasshoppers of various 

 sizes. How do they differ from the adult ? 



Observe method of locomotion, taking of 

 food, kinds of food, and breathing movements 

 of grasshoppers. When opportunity offers, 

 carefully observe them in the fields and 

 record your observations. 



Read the "Molting of the Grasshopper," 

 Chapter IX in Weed's "Life Histories of 

 American Insects." 



Grasshoppers are called locusts in the 

 old world, but rarely in America. The so- 

 called seventeen-year locusts are really 

 cicadas, belonging to an entirely separate 

 order of insects (the Hemipterans). 



324. Study of Butterfly, or Moth. (L) Examine a butterfly with 

 regard to the points of structure already seen in a grasshopper. The 

 chief differences to be observed are: (1) Form and size of wings 

 and presence of scales (use hand-lens and microscope). On some 

 butterflies and the related moths the scales are hair-like. (2) Legs 

 of butterfly are adapted for clinging, not jumping. (3) Antennae 

 are club-shaped on a butterfly, feather-like on a moth. (4) Moutb- 



FIG. 132. Arrangement 

 of the larger tubes of 

 the air-tube or tra- 

 cheal system of a 

 cockroach. ( After 

 Miall and Denny.) 



