AQUATIC INSECTS IN THE ADIRONDACKS 



429 



Ephemera varia Eaton 



Plate 11, figures 3, 4 



1861 Ephemera decora Hageu, Synopsis Neur. N. Am. p. 38 (d e c o r a was 



Walker's name for anotber species) 

 1875 Ephemera decora Hagen, Rep't U. S. geol. sur. terr. for 1873 ; p. 578 

 1885 Ephemera varia Eaton, Linn. soc. Lond. Trans. (2) 3:69-70, pi. 63, 



fig. 12h 

 1892 Ephemera decora Banks, Am. ent. soc. Trans. 19:345 (listed) 



This dainty New England species was common about Little Clear 

 creek, associated with the preceding species, with which it agrees quite 

 closely in habits. Imagos, while not sought outside our cages, were 

 often seen sitting lightly on the bushes near the banks of the creek. The 

 nymphs were abundant in the bed of the creek till the first of August. 



Nymph. PL n, fig. i, 2 Length of body 18 mm; setae 8 mm addi- 

 tional ; abdomen 11 mm; antennae 4.5 mm. 



Color yellowish ; abdomen with a pair of submedian, longitudinal, 

 brown streaks, laid on yellow ones, which they divide. 



Antennae sparsely hairy, much surpassing tlie tips of the tarsi. Man- 

 dibular tusks, approximate, slender, bare, gently up curved and divergent 

 at the tips; femora and tibiae moderately dilated and bearing on their 

 flattened edges copious fringes of hairs. 



Gills as in Hexagenia, but slenderer, and less deeply tinged with 

 purple color. 



Order ODONATA 



Dragon Jlies 



The dragon flies are all aquatic. They frequent fresh water in all sorts 

 of situations, and are probably the most important predatory aquatic 

 insects. They are strictly carnivorous in all 

 stages. The adults feed on a great variety 

 of insects, and the larger dragon flies habitu- 

 ajly eat the smaller ones. The nymphs are 

 very voracious, and in many species can- 

 nibalistic, the larger nymphs eating the 

 smaller ones; but they eat chiefly other 

 aquatic insects, worms, crustaceans, fish fry, 

 and tadpoles. 



The nymphs may be conveniently grouped 

 according to habits as follows. 



a Burrowing nymphs, with depressed, wedgcd-shaped heads, abbreviated and 

 flattened antennae, approximated fore legs, and external burrowing hooks 

 at the ends of the fore and middle tibiae. These burrow along on the bot- 

 tom of the pond or stream, just beneath the layer of silt, with the tip of the 

 abdomen turned upward and reaching the water for respiration (Gomphinae) 



Fig. 6 Face of nymph of S y m p e t - 

 rum i 1 1 o t u m Hagen, showing the 

 enormous mask shaped labium 



