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INSECTS AFFECTING THE POTATO. 



or more, on the under surface of the potato leaf, and 

 occasionally also upon the leaves of grass, smart- 

 weed, or other plants in the potato field. They 

 hatch about a week later into peculiar little grubs 

 (b) that feed upon the foliage a few weeks. They 



Fig. sT. Colorado Potato-beetle: a, a, eggs; 6, 6, larvae; c, pupa; d, d, bee- 

 tles : e, wing of beetle, magnified. 



then descend to the ground, where just beneath the 

 soil surface, or under rubbish above it, they change 

 to pupa? (c). About ten days later they emerge as 

 perfect beetles. There are from two to four annual 

 broods, the number varying with the latitude ; and 

 the insect hibernates in the beetle state. 



Like most other insects, the Colorado Potato-beetle 

 fluctuates greatly in numbers and destructiveness. 

 In any given locality it will be very destructive for 

 a period of years, and then there may be several 

 seasons when its injuries will hardly be noticed. 



