62 



INJURIOUS AND USEFUL INSECTS 



"collar," and the metathorax is also much reduced. A 

 narrowed waist connects the abdomen with the thorax. 



Lay one of the wings in a watch-glass with a little alcohol, 

 and brush it with a camel-hair pencil cut short. Brush until 

 the wing is bare, and the veins appear. Examine a' few loose 

 scales with the microscope, and also study a bit of wing from 

 part of which the scales have been removed, while another part 

 is undisturbed. The scales are set in rows, and each is attached 

 by its slender tip to a hole in the wing. The pattern of the veins 

 is often employed as an aid to the classification of Lepidoptera. 



15. CABBAGE WHITE BUTTERFLIES {Pietis) 



Three species of these mischievous insects are commonly 



met with in this 

 country, their 

 caterpillars feed- 

 ing upon cabbages 

 and allied plants, 

 such as mustard 

 and turnips. They 

 are distinguished 

 as the large, the 

 small, and the 

 green-veined cab- 

 bage whites. The 

 butterfly of the 

 large species mea- 

 sures 60 mm. or 

 more across the 

 expanded wings, 

 that of the smaller 

 species is only 

 about 50 mm., 

 while the green- 

 veined butterfly is 

 about as big as 

 the second, or a 

 little smaller. The 



44. — Large cabbage white. Ihe upper , . , 



figure represents the female. markings On the 



