» Species recurvata (Dark Green Drake)
Common Names
This is the largest species of mayfly in North America. Sometimes it appears together with the Hexagenia limbata hatch or the Ephemera guttulata hatch, but in other places it creates excellent action on its own. Where & WhenRegions: East, Midwest
Time Of Year (?): Late May to July
Preferred Waters: Both lakes and streams
Litobrancha recurvata is abundant in fewer places than other important Ephemeridae like Hexagenia limbata or Ephemera simulans, but where it does exist it has dense populations which produce good hatches.
Emergence begins in late May in Pennsylvania. Michigan and Wisconsin follow a week or so later and peak in June. The hatch may continue through July and even into August to the north. It only lasts from three to five days on a given stretch of stream.Hatching BehaviorThese flies take a long time to escape their shucks (Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.) in the surface film, and they are unusually prone to being stillborn (Stillborn: In fly fishing, a stillborn insect is one which got stuck in its nymphal or pupal shuck during emergence and floats helplessly on the surface instead of flying away. It is a specific class of cripple, although it is sometimes used interchangeably with that term.) or crippled. Emerger and cripple (Cripple: In fly fishing, a cripple is any insect which has been injured or deformed so that it cannot escape the water. This may include stillborn emergers or fully emerged adults which have been damaged, often by wind or waves, so that they can no longer fly. Trout often favor eating crippled insects.) patterns are recommended.Spinner BehaviorTime Of Day: Dusk
These mayflies return as spinners one to three days after hatching. Typically the duns from more than one day will return as spinners together, creating concentrated and exciting hatches. The females fall to the surface to lay their eggs.Nymph BiologyCurrent Speed: Slow
Substrate: Firm silt
Environmental Tolerance: Intolerant of warm water or pollution
Caucci and Nastasi in Hatches II describe their experiments rearing these nymphs. They found that the grown nymphs, like other large burrowers, are extremely hardy, but the early nymphal stages are very sensitive to pollution or warm temperatures.
They take two to three years to mature before hatching.
Recent Discussions of Litobrancha recurvata
I agree with the nymph and emergence coments aboveCaucci and Nastasi's comments and other comments above are correct. They are really hardy and impressive nymphs when they near maturity. Litobrancha nymphs prefer fine silty, mucky habitats in streams. They can be abundant in mucky side channels to the main stream. Their emergence occurs over a 5-day span, with the large majority emerging within a 3-day period. Therefore, large emergences are rarely encountered. When they do occur, they can be very impressive.
From my experience collecting and rearing these critters, they have a 2-year life cycle in PA and MD. They increase tremendously in size in their second year. Emergence occurred in late May into early June about a week before that of green drakes (Ephemera guttulata).
Reply Your Thoughts On Litobrancha recurvata:
You must
log in at the top of the page to post. If you haven't registered yet, it's this easy:
Tweet