CHAPTER V 



THE MAY-FLIES (Order Ephemerida) and STONE- 

 FLIES (Order Plecoptera) 



AY-FLIES, lake-flies, or shad-flies, common names for 

 the insects of the order Ephemerida, are familiar to 

 people who live on the shores of lakes or large rivers, 

 but are among the unknown insects to most high-and- 

 dry dwellers. 



Travelling down the St. Lawrence River from 

 Lake Ontario to Quebec one summer, I had hosts of 

 day-long companions in little May-flies that clung to 

 my clothing or walked totteringly across my open book. The summer 

 residents of the Thousand Islands get tired of this too-constant com- 

 panionship, and look resentfully on the feeble shad-fly as an insect pest. 

 One evening in August, 1897, my attention, with that of other strollers along 

 the shore promenade at Lucerne, was called to a dense, whirling, tossing 

 haze about a large arc light suspended in front of the great Schweizerhof. 

 Scores of thousands of May-flies, just issued from the still lake, were in 

 violent circling flight about the blinding light, while other thousands were 

 steadily dropping, dying or dead, from the dancing swarm to the ground. 

 Similar sights are familiar in summer-time in this country about the lights 

 of bridges, or lake piers and shore roads. This flying dance is the most 

 conspicuous event in the life of the fully developed, winged May-fly, and 

 indeed makes up nearly all of it. With most species of May-flies the winged 

 adult lives but a few hours. In the early twilight the young May-fly floats 

 from the bottom of the lake to the surface, or crawls up on the bank, the 

 skin splits, the fly comes forth full-fledged, joins its thousands of issuing 

 companions, whirls and dances, mates, drops its masses of eggs on to the 

 the lake's surface, and soon flutters and falls after the eggs. It takes no 

 food, and dies without seeing a sunrise. Sometimes the winds carry dense 

 clouds of May-flies inland, and their bodies are scattered through the streets 

 of lakeside villages, or in the fields and woods. Sometimes the great swarms 



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