ANTS, BEES, AND WASPS 151 



infested by a tiny parasite that develops in them. An ex- 

 ceedingly minute fly deposits its eggs within the eggs of 

 the Currant Worm — one in each. The former hatch into 

 tiny footless larvae that develop at the expense of the 

 material of the Currant Worm egg. Finally these larvae 

 pupate arid later change to tiny adult flies. 



This Currant Worm was originally a native of Europe, 

 having been introduced into America many years ago. Its 

 injuries may be prevented by spraying or dusting the 

 bushes with hellebore when the larvae are young. It should 

 not be applied when the fruit is ripening. 



In addition to the Currant Worm, there are a number 

 of other insects belonging to this group. A very similar 

 species feeds upon the foliage of raspberries and is called 

 the Raspberry Sawfly. Another feeds upon strawberry 

 leaves and is called the Strawberry Sawfly. Still an- 

 other, which is an unusually large species, feeds upon 

 willow and is called the Willow Sawfly. Avery character- 

 istic form often injures grape leaves and is sometimes 

 called the Grape Slug. 



Two similar and characteristic sawfly larvae are found 

 upon pears, plums, and cherries, and upon roses. These 

 have in their younger stages curious slimy skins and eat 

 only the surface of the leaves, causing a characteristic and 

 easily recognized injury. The presence of this slimy coat- 

 ing enables one to kill them readily by applying almost any 

 fine powder, such as road dust or air-slaked lime to the af- 

 fected foliage. The particles will adhere to the larvae and 

 eventually cause their death. 



Most of these false caterpillars are marked in colors of 

 striking contrast which indicate that they have some method 

 of defense from birds. They are thus examples of what 

 the naturalists call warning coloration, and they seem to 



