Insecta. 21 



(X) The perfect butterfly. 



3. The cabbage butterfly belongs to the family Pieridae, genus 

 Pieris, species rapae. 



There are several species of the genus Pieris, just as there may 

 be several persons in one family ; as in a directory we read : 

 " Smith, Charles," " Smith, Edmund " ; so we read : Pieris rapae, 

 Pieris protodice. 



What is the meaning of the word " rapae "? 



Occasionally a larva will fail to go through its proper changes ; 

 this is generally caused by some parasite, the most common of 

 which is an ichneumon larva. The adult of some ichneumon fly 

 lays it eggs on the body of the cabbage worm ; these eggs hatch 

 out as worms, bore into their host, and live on the juices and tissues 

 of the cabbage worm, till it dies from exhaustion (though the 

 cabbage worm often lingers, and the parasitic larvae complete their 

 transformation first), and the parasitic larvae become pupae, and 

 hatch out as perfect ichneumon flies. 



Look for holes in pupae which fail to complete their transforma- 

 tion ; often holes may be found in them where the ichneumon flies 

 have made their escape. If a pupa blacker than usual be found, put 

 it in a vial, or pill box, and catch the ichneumon flies as they emerge. 



Topics for Reports. The Clothes Moth. The Silkworm. The 

 Tent Caterpillar. The Codling Moth. Cecropia. Polyphemus. 

 Cutworms. 



THE HOUSE FLY. 

 THE PARTS OF THE BODY. 



1. The head, the foremost, or anterior, part. 



2. The thorax, or middle portion. 



3. The abdomen, the hinder, or posterior, part. 



THE HEAD. 



i. Examine the eye with a strong lens, and under a low power 

 of the microscope, to discern its parts or facets. What shape 

 have the facets? 



