81 



angle. First two segments of the abdomen white, remain- 

 ing segments pale yellow. Female larger and lighter in 

 color than the male, discal and terminal dots more plainly 

 visible and hind wings lighter. 



Habitat. New York, Illinois. 



There are a male and a female of this species in the National 

 Museum, labelled " From Scirpus, D. C. Kellicot, Buffalo, 

 N. Y." It is probable that this insect is a stem borer in 

 Scirpus. 



Named in honor of Prof. S. A. Forbes, from whom it 

 was received, in recognition of his valuable contributions 

 to economic entomology. 



