May, 1915.] Hemiptera-Heteroptera of Ohio. 503 



Family Gerrid^. 



Gerris canaliculatus Say, 



One macropterous specimen, taken by the junior writer, 

 October 15, 1913, on the Olentangy River (Ohio State University 

 Farm.) 



Gerris conformis Uhler. 



One specimen, taken at Ironton, Lawrence Co., by Mr. R. 

 C. Osbuni; numerous specimens, collected by the junior writer 

 at Berea, Olmsted Falls, and Columbus. This is a lacustrine as 

 well as a fluviatile species. In the localities cited, several nymphs 

 and adults were taken at various times during the past summer 

 on ponds, small lakes, and streams. During the winter, they 

 hibernate as adults and begin to copulate in early spring. The 

 ova are deposited on material just beneath the surface of the water. 

 In an aquarium, they were laid on floating cork just beneath the 

 surface film and fastened with a viscous substance which is water- 

 proof. These eggs began hatching in eleven days and the first 

 adults appeared thirty-four days later, several requiring a few 

 days longer to complete their metamorphosis. There are proba- 

 bly several generations during the summer, as nymphs and adults 

 were taken on these same bodies of water during the latter part 

 of the season. All specimens reared and collected were macrop- 

 terous. 



Limnogonus hesione Kirkaldy. 



This tropical species is a noteworthy addition to our fauna. 

 It has been recorded from Florida and Darien, Panama by Kirk- 

 aldy (Entomologist, 1902, p. 137). 



One macropterous cT , taken during the past summer at Gallon, 

 Crawford Co., by Mr. G. K. Rule; immense numbers of apterous 

 cf and 9 , collected by the junior writer at Buckeye Lake, and at 

 Minerva Park north of Columbus during September and October 

 1913, also at the latter locality and at the Ohio State Fair Ground 

 in Columbus during September and October 1914. At these various 

 times, numerous specimens were found copulating. Last October, 

 several cf and 9 were placed in an aquarium; in a few days eggs 

 were deposited on floating cork just beneath the surface of the 

 water. The males died a few days after coition, and the females 

 a few days after the ova were deposited. Many of the individuals 

 remained almost constantly in coitu for several days. As the 

 ova and no adults could be found in early spring, the winter is 

 probably spent entirely in the egg stage, while, later on and during 

 the latter part of the summer, immense numbers were found on 

 these same bodies of water. The eggs are slightly enlarged at one 

 end and about three times as long as wide. They vary in length 

 from one to one and one-third of a millimeter, and are of a dirty 

 greenish-yellow color which becomes somewhat darker with age. 



