PROJECTS AND QUESTIONS 231 
7. The cabbage butierfly.— With the aid of the description given 
elsewhere in this book, try to identify this butterfly. If possible find 
cabbage or cauliflower leaves that are infested with the worms. They 
will probably also have some eggs upon them. On what part of the 
leaf are the eggs? Are they single or in masses? Notice how the worms 
attack the leaf. Put into an insect cage a leaf with some of the worms 
and watch for the change into the pupa state. How does the pupa look 
and how does it behave? If it is early in the season, it will change to a 
butterfly in about ten days. If it is too late, then the change will not 
take place until spring. Find out from some good gardeners how to 
treat cabbage and cauliflower for this pest. 
8. Currant worms. — After the leaves are unfolded on the currant 
bushes, look for flies that are hovering around them. Catch a few, put ° 
them in a glass, and examine them. Are they ordinary flies or do they 
have four wings? If they have four wings, they are sawflies and are not 
related to the common flies, but to bees and wasps. Try to find some of 
their eggs on the leaves, also some tiny green worms that may have 
hatched out. Bring into the house a green twig with some of these 
larve, put the twig in a glass of water or an insect cage, and watch the 
insects eat and grow. In a cage you should be able to keep them until 
all the transformations take place and the adult flies are developed. 
In a currant patch verify by observation as far as possible the life 
history of these insects as given elsewhere in this book. Also try the 
hellebore' treatment as suggested. 
9. A fly trap. —If you are troubled with many flies, construct a 
fly trap and place it at the kitchen door or in some other location where 
they are abundant. A successful device for catching them in large 
numbers, recommended by the Minnesota Experiment Station, is shown 
in these pictures. As high as 12,000 flies a day have been caught in 
one of these traps. 
The trap is 24 inches long, 12 inches high, and 8 inches wide. Ordinary 
wire mosquito screen is used in its construction. The bait in the pan 
is bread and milk, frequently renewed; spoiling meat will attract still 
more flies. The flies may be killed by pouring hot water over them. 
The trap is made in three sections that are held together by hooks at 
each end and may be readily taken apart to empty the jail or to refill 
the bait pans. (See p. 232.) 
c, made of screen, serves as the jail. 
