64 INSECTA 



development from egg to adult requires only about two weeks, 

 and for this reason the fly makes a good study. 



Plant-feeding caterpillars are less repulsive, and the cabbage 

 butterfly develops in a few weeks and makes an interesting 

 study; but try any and everything you find. 



1. Development. 



(1) Watch the development of the eggs or larvae in the 



breeding jar from day to day, and make note of every 

 change. 



(2) If you can get them, save a specimen in each stage 



of the development for your collection. (Place the 

 larvae in a solution of formaldehyd.) 



(3) What is the duration of each stage of development? 



What is the name of each stage? 



(4) Sketch each stage in your notebook. 



2. Activities. 



(1) Observe and describe the following activities: 



(a) Eating. 



(b) Crawling or walking. 



(c) Molting of the larvae. 



(d) The spinning of a cocoon, or the forming of a pupa- 



case. 



(2) Questions. 



(a) Is the insect herbivorous or carnivorous? 



(b) How does it obtain its food in each stage of its ex- 



istence — by biting, sucking, or lapping? 



(c) Does it avoid or choose the light? 



3. Economic Importance. 



(1) In what stage, if any, is it injurious to vegetation? 



(2) How would you get rid of it if injurious? 



(3) Does it prey upon any other insects in any stage of its 



development? Is it preyed upon by any other insect? 



4. Intelligence. 



(1) State at least three instincts v/hich you have seen dis- 



played by this insect. 



(2) Have you seen any intelligent action? If so, what? 



(3) Try an original experiment to see if you can make 



this insect choose to act in a way different from the 

 usual one. Record your results. 



