138 



CIVIC BIOLOGY 



all that it does. It sips nectar from flowers, and does much to 

 fertilize them. The female imago is distinguished by having 

 two black spots upon its fore wing while the male has only one. 

 From your specimens in the laboratory study the butterfly, 

 noting its parts. Draw from the side and from above. Make 



_^ drawings of the head from the 



side, one with the proboscis 

 curled up, and another with it 

 extended. (Place a little thin 

 sirup near the head and watch 

 the butterfly unroll its proboscis 

 and sip it.) Compare the struc- 

 ture of the body with that of 

 the pupa. Mount, according to 

 directions, the complete life his- 

 tory of the butterfly (Fig. 73). 

 Control of the pest. Artificial 

 means of control are (1) Paris 

 green, sprinkled over the leaves, 

 killing the worms but not injur- 

 ing the plant; (2) kerosene 

 emulsion as a spray ; (3) water, 

 heated to 130 F., may be used 

 without injury to the plant; 

 (4) systematic " netting " of 

 adults. The most effective meas- 

 ure, however, has been the in- 

 troduction of its natural enemy, 

 Apanteles glomeratm. 



This minute wasp-like insect deposits its eggs in the body 

 of the cabbage caterpillar where they soon hatch and feed upon 

 the tissues of the host. They grow until they are about to 

 pupate, and then eat their way out and spin their silken 

 cocoons on or near the body of their enfeebled host. The 



FIG. 74. Convenient arrangement 

 for studying larvae 



Two tumblers with card between 



