REPORT OP THE STATE ENTOMOLOGIST 1903 97 



BENEFICIAL INSECTS 



SYNOPSIS OF CERTAIN GENERA OF THE OPHIONINI 



The following account of species belonging to various genera 

 of this group is the result of a study, extending over some years, 

 originally begun at Cornell University under the auspices of 

 Prof. J. H. Coinst'ock, to whom the writer is under deep obliga- 

 tions for assistance. The original assignment covered the species 

 placed in this genus by Cresson, and owing to many other matters 

 demanding attention, we have reluctantly decided to publish our 

 results without attempting to extend our studies so as to include 

 all the members of this group, particularly because of lack of 

 time, and specially since a number of genera are represented 

 only by foreign species. We also take this opportunity to express 

 our obligations to Dr W. H. Ashmead, curator of the Hymenop- 

 tera, United States National Museum, who in recent years has 

 kindly loaned us specimens and afforded material aid in our sys- 

 tematic study. 



This group includes some of our larger and more common para- 

 sites, and to the species comprising it much credit is due for ma- 

 terial aid in controlling a number of our insect r>ests. For ex- 

 ample the long-tailed Ophion, E r e m o t y 1 u s m a c r u r u s 

 Linn, is a common parasite of large cecropia larvae and allied 

 species. These large caterpillars are rarely abundant enough to 

 attract attention by their ravages, and one reason for this is un- 

 doubtedly the activity of their parasites, foremost of which stands 

 the long-tailed Ophion. 



Value as parasites 



The other species of this group have been reared from a large 

 number of hosts, and there is no reason for regarding several of 

 them as of less value than Eremotylus m a c r u r u s Linn. 

 The following statistics will give some idea of their abundance 

 and, as the life of the host with its attendant possibilities is de- 

 stroyed as each develops, they also give some idea of the economic 

 value of the species. Six trap lanterns were in operation during 

 the entire season of 1889 at Cornell University for the purpose of 

 ascertaining the value of lights for destroying insects, and nearly 



