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NEW HAMPSHIRE COLLEGE 



officers of that station. The egg is shown at a ; the hxrva at 

 6; the pupa at c; and the adult at d. These figures were 

 made from the parasite as it preys upon the larva of a borer in 



R Detmers, del. 



Fig. 4. Life stages of a Pimpla Parasite. (By the courtesy of the Ohio Exper- 

 iment Station.) 



the stems of the evening primrose^ in which case the parasitic 

 grub feeds externally on its host as shown at e. The most 

 abundant species of Pimpla^''- however, as a parasite of the tent 

 caterpillar lives inside the host, which generally is not killed 

 until after it has spun its cocoon. 



In addition to the very general attack of the common tent 

 caterpillar, there have been in many parts of the state more 

 dangerous outbreaks of the Forest Tent Caterpillar.^ This 



Fig. 5. Moths of Forest 'J'ent Caterpillar : «, Male ; ^, Female. Natural size. (Original.) 



insect has been known for many years to become destructive at 

 intervals to a great variety of trees. Its outbreaks are more 

 periodic than those of the common species, and, while they 



1 Oenothera biennis. " Pimpla conQiiisitor. " Clisiosanipa disstria. 



