ORCHARD LIFE. 



185 



3. When the larvae are full grown, determine 

 where the pupa state is passed, and make a drawing 

 of the puparium. The pupa state of most flies, in- 

 cluding the pomace-flies, is passed within the dried 

 skin of the larva. This dried skin, which serves the 

 purposes of a cocoon, is termed a puparium {^pu-pa'- 

 ri-um). 



4. Put some puparia in a vial in order to deter- 

 mine the duration of the pupa state. 



5. When the adult flies emerge in your breeding 

 cage, save some specimens for your collection, and 

 put some living ones in a cage with decaying fruit 

 which is not infested. If you have more than one 

 species of pomace-flies, put the different species in 

 different cages. Try to discover the eggs when they 

 are laid, and to determine the duration of each stage 

 of the insect. 



6. Write an account of the pomace-flies that you 

 have studied. 



7. Prepare a set of specimens for your collection. 

 The pomace-flies belong to the order Diptera, the 

 family MusciD.E (Mus'ci-dse), and to the genus Dro- 

 sophila {Dro-soph' i-ld). 



