58 INSECTS. 



1. Their position on the leaf while feeding. 



2. Their manner of feeding. 



3. The effect of their operations on the leaf. 



4. Under what conditions one leaf is ordinarily deserted 

 for another. 



Study of a Live Specimen. Study the adult. 



Examine the head with a lens. Note the position of 

 its parts. Find eyes, ocelli, and antennae. 



Observe that the mouth parts are modified into a jointed 

 proboscis (the rostrum). Count its joints. Note its posi- 

 tion. At the base of the rostrum above is the rudimen- 

 tary labrum. Mandibles and maxillae are represented by 

 two pairs of bristles within the sheath of the rostrum. 

 The sheath itself is supposed to be the modified labium 

 consolidated with its palpi. The whole rostrum is well 

 adapted to making punctures, and to sucking up through 

 them the juices of plants. 



Observe for the thorax its shape and the relative de- 

 velopment of its segments. 



On the mesosternum at either side, near each middle 

 coxa, find a small pore (an osteole) surrounded by a small 

 granular space (the evaporating surface). From these 

 osteoles is exuded the fluid Avhich gives the squash bug its 

 peculiar odor. This odor is protective, because it makes 

 the bug a less dainty morsel of food for other animals. 



Examine the legs. For what kind of locomotion are 

 they adapted? Find coxa, trochanter, femur, tibia, and 

 tarsus. How many joints in the tarsus ? 



Examine the wings. Observe carefully the difference 

 between inner and outer halves of the fore wing, the former 

 thickened and horny, the latter membranous and traversed 

 by numerous veins. Compare fore and hind wings in 

 form, size, texture, and position. Draw the wings of one 

 side (enlarged). 



