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.
Lastchance on Feb 4, 2012February 4th, 2012, 3:48 am EST
If I'm not mistaken, the first baetis nymphs that appear in the spring in PA have a light olive abdomen and a dark olive thorax. Which species is this? They appear to be size 18s and 20s.
Bruce
PaulRoberts on Feb 4, 2012February 4th, 2012, 4:35 am EST
The first to appear in NY (I was aware of, and if I remember correctly, AND if the name hasn't changed!) was tricaudatus. It's a #16/#18 (Mustad) as a dun. If the stream gives a second brood, the later summer ones are smaller.I've found tricaudatus here in CO Front Range streams too, and believe they are our first emergers. They are also #16/#18 as a dun.
Ah! Nymphs, you say... Spring Baetid nymphs run from a light golden olive to a dark brownish olive. I assume that the lighter ones, often smaller, are lesser developed tricaudatus (they don't all mature at exactly the same time, dependent on thermal units apparently), and some are likely immatures of other species. The largest ones (#18/#20 is a good ballpark) with the nearly black wing-buds are the ones about to emerge.