On The Occurrence of a Mermis Epidemic Amongst Grasshoppers

While engaged in some investigations on grasshoppers, near Dummerston Station, southern Vermont, this past summer (1917), our attention was attracted to a high mortality amongst these insects (Melanoplu8 atlanis and M. bivittatus). The two species, especially M. atlani8, are extremely bad pests in this region of the country, attacking corn, wheat, oats and clover to such an extent that during certain summers the farmers become nearly frantic. Therefore, the high mortality amongst the grasshoppers, which appeared during the latter part of August and the early part of September, was exceedingly gratifying. We soon discovered that this mortality was due to a species of’ Nematode belonging, as we supposed at the time, probably to the family Mermithidm. Subsequently (Sept. 0, 5 and Oct. 6), we sent large shipments of these worms to Dr. N. A. Cobb, of Washington, D. C., for identification. Dr. Cobb was able to give us only a provisional identification on account of the utter absence of male in all of our shipments. We made collections of parasitized. grasshoppers from a large variety of fields and as stated, sent a large number of specimens, but curiously enough no males were found. Dr. Cobb in a letter said: "Nothing I have learned would preclude your specimens from belonging to the same species as that referred to by Leidy under the name of Mermis ferruginea, which