60 STUDIES OF ANIMAL TYPES 



have been boiled in potassium hydrate (KOH) until they 

 are soft. How many bristles are in the beak? The part 

 of the beak in which they are inclosed is supposed to be 

 the lower lip and labial palpi grown together. These form 

 a sheath to inclose the bristlelike mandibles and maxillae. 

 Note the groove on top of the lower lip in which the bristles 

 lie. 



Make a drawing of the mouth parts. 



Recall the structure of the mouth of a grasshopper and 

 the manner in which that insect obtains its food. The 

 squash bug obtains its food by inserting its beak into the 

 tissues of the leaves and sucking up the juices. What 

 can you say in regard to the adaptations of the mouth 

 parts of the grasshopper and of the squash bug to their 

 different functions? 



B. LIFE HISTORY OF THE SQUASH BUG. The adult 

 insect lives over the winter in crevices or beneath boards 

 or rubbish, and early in the spring lays the eggs in irregu- 

 lar clusters, usually on the under sides of the leaves of 

 squashes, melons, and cucumbers. The eggs are dark 

 yellow-brown, with a glossy surface, and are plainly visi- 

 ble to the unaided eye. Are the clusters of eggs equal in 

 size? How many eggs in one cluster? Are the eggs 

 ever laid singly? 



The eggs may be brought into the laboratory and placed 

 on squash plants in breeding cages. It would be more satis- 

 factory, perhaps, to take a breeding cage to the field or 

 garden and place it over a plant and watch the life history 

 of the insect there. It may lend interest to allow the pupils 

 to watch the life history of this insect in their own home 

 gardens. Note the length of time it takes the eggs to hatch. 

 Compare a young nymph with an adult, and note the differ- 



