Hex Mayflies
Hexagenia limbata
The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.
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This is the first of it's family I've seen, collected from a tiny, fishless stream in the Cascades. The three species of this genus all live in the Northwest and are predators that primarily eat stonefly nymphs Merritt R.W., Cummins, K.W., and Berg, M.B. (2019).
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Giant Water Bug Genus Belostoma (Toebiters)
Where & when
In 188 records from GBIF, adults of this genus have mostly been collected during September (15%), August (13%), July (13%), May (12%), October (12%), June (11%), and April (7%).
In 16 records from GBIF, this genus has been collected at elevations ranging from 246 to 12303 ft, with an average (median) of 883 ft.
Genus Range
Specimens of the Giant Water Bug Genus Belostoma
2 Adults
I'm glad I finally got one of these Belostoma water bugs under my good camera. I had been hoping to get one in my kick-net samples for a while with no luck, but I ended up finding this one drifting midstream just below the surface while I fished. I have frequently seen water scorpions do that, too, and I'm beginning to suspect that is a common situation travel for these large Hemiptera bugs, and perhaps the way trout are used to seeing them.
I haven't seen the imitation of these things stressed, but in August 2003 on one of my favorite rivers the largest brown trout I kept had stomachs full of these things.
Discussions of Belostoma
Anyone else find these to be important?
2 replies
Posted by Troutnut on Jul 26, 2006 in the species Belostoma flumineum
Last reply on Oct 9, 2006 by GONZO
Back when I was just starting to learn to fly fish and still kept quite a few fish, I autopsied the stomachs of a couple 17-19 inch brown trout in August and found them packed with these Belostoma flumineum bugs.
I haven't tied a reasonable imitation yet, but if those fish (from a few miles apart on the same river) were so fond of them an imitation is probably a great idea. It would be good to figure out where and when these things are important.
None of the fly fishing literatue I've seen has dealt with them at all, except for mentioning their existence in passing.
I haven't tied a reasonable imitation yet, but if those fish (from a few miles apart on the same river) were so fond of them an imitation is probably a great idea. It would be good to figure out where and when these things are important.
None of the fly fishing literatue I've seen has dealt with them at all, except for mentioning their existence in passing.
Start a Discussion of Belostoma
References
- Merritt R.W., Cummins, K.W., and Berg, M.B. 2019. An Introduction to the Aquatic Insects of North America (Fifth Edition). Kendall/Hunt Publishing Company.
Giant Water Bug Genus Belostoma (Toebiters)
Taxonomy
Species in Belostoma
Belostoma flumineumElectric Light Bugs
2
18
Species in Belostoma: Belostoma flumineum
8 species (Belostoma bakeri, Belostoma confusum, Belostoma ellipticum, Belostoma flusciventris, Belostoma lutaria, Belostoma saratogae, Belostoma subspinosa, and Belostoma testaceum) aren't included.