Quick bug collecting and gear test trip
I was out in the Issaquah Alps doing some puppy training yesterday and decided to bring my bug-collecting stuff along. Mostly it was an excuse to get more practice with my new microscope and test out a new system for holding bugs I've sorted to photograph.
Previously, I've had some sensitive specimens quickly die after being sorted into their own separate containers or compartments, either because the water warms up more quickly in the compartments or the oxygen runs out. This leads to specimens that aren't in ideal shape for photos. To solve the problem, I drilled holes in an ice cube tray and gorilla glued some little squares of 250-micron Nitex mesh (drift sampling net material) to the outside. Then I stick the whole thing in a tub of aerated water with a freezer block. This allows me to separate different types of bugs into lots of compartments, while still having them aerated and cooled from a common, larger reservoir of water.
It worked great. Some typically fragile Baetids and Heptageniids stayed in good shape for a very long time, more than long enough to take photos. I didn't photograph any of the Heptageniids, though, because they were Cinygmula and Rhithrogena nymphs for which there are no species keys available.
My favorite new addition was Claassenia sabulosa, a very pretty golden stonefly nymph.
There were also a lot of Hesperoperla pacifica nymphs in the sample, but I already have good photos of those.
Female Baetis bicaudatus (BWO) Mayfly Nymph
View 12 PicturesI collected this one along with a male that was quite a bit smaller but equally ready to emerge in mid April.
I spent (Spent: The wing position of many aquatic insects when they fall on the water after mating. The wings of both sides lay flat on the water. The word may be used to describe insects with their wings in that position, as well as the position itself.) quite a while on the identifications, because they really don't look very much like the Baetis bicaudatus nymph I caught last year in Idaho. However, the presence of hind wing pads (
Wing pad: A protrusion from the thorax of an insect nymph which holds the developing wings. Black wing pads usually indicate that the nymph is nearly ready to emerge into an adult.) rules out Acentrella turbida, the lack of a fringe of long setae (Seta: Little hairs on insects.) on the tibiae (Tibia: A middle segments in the leg of an insect, located between the femur and the tarsus.) rules out Acentrella insignificans, range rules out Heterocloeon and Iswaeon, and the thumb-like projection on the labial palp (
The wing pads on this final instar Baetidae
mayfly nymph are extremely dark.
Palp: A long, thin, often segmented appendage which can protrude from certain insect mouth parts such as the maxillae. Also known as the < />palpus.) points to Baetis. Thus, Baetis bicaudatus is a fairly confident ID, and it's not too surprising that it looked different from my previous specimen because bicaudatus is thought to be a species complex with multiple types that haven't been fully sorted out yet.
The palp on the maxilla of an Ephemerella
nymph (detached and photographed under a microscope) is highlighted in red here.
The microscope pictures for this specimen aren't from the same exact nymph, but a mixture of a few others of the same kind that I didn't mind dissecting.
Most recent comments on this post (latest on top)
|Troutnut||April 16th, 2021, 7:03 pm || |
|Yeah, I've taken plenty of photographs of specimens I know I can't identify beyond genus in the past, and I'm sure I will in the future. But I'll probably be a but more selective about them, i.e. favoring distinctive-looking mature specimens, because otherwise I'll just have dozens of nondescript "Cinygmula nymph" nobody's looking at. For now, I'm trying to focus more of my effort on adding taxa I don't have well-represented yet.|
|Jason Neuswanger, Ph.D.|
Troutnut and salmonid ecologist
|Millcreek||April 16th, 2021, 11:57 am || |
|Nice photos. You should give some thought to photographing species for which keys are unavailable. Even if you can't get past genus you at least have a record and possibly can identify it if someone does come up with a key. Anyway I've really been enjoying the western species you've been photographing.|
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