Tuesday, September 25, 2012

EPT Species List for Central Virginia: Photos of Small Minnow Mayflies


With cloudy weather ahead, and not much water in a lot of our streams, my regular outings might be interrupted this week.  So I thought I might begin work on a project that may be of interest to some of our readers.  I'll post photos of the insects noted in the species list posted on September the 8th.  I'll work through the "orders" in order -- Mayflies (Ephemeroptera), Stoneflies (Plecoptera), and Caddisflies (Trichoptera) and focus on the families one at a time -- where the family contains a fair number of species -- and group the families together when the species noted are few.

For each species, I'll add the approximate size as that is given in Steven Beaty's "The Ephemeroptera (or Plecoptera or Trichoptera) of North Carolina."  I'll also note the time of year when I typically see nymphs of that species (though there are always exceptions).

Keep in mind that colors/hues of individual nymphs may vary by stream -- patterns do not.  Patterns are normally species specific, but in some species, male and female patterns can vary (they're "sexually dimorphic").

I. Ephemeroptera

 Baetidae (Small minnow mayflies)

1. Acentrella nadineae.  Size: 5-5.8mm; Season: Summer -- Early Fall.

a. male

b. female


2. Acentrella turbida.  Size: 4-6mm; Season: Spring, Summer, and Fall

a. male

b. female


3. Baetis flavistriga.  Size: 4-6mm; Season: Summer.

a. male

b. female


4. Baetis intercalaris.  Size: 5-6 mm: Season: Summer and Fall.

a. male

b. female


5. Baetis pluto.  Size: 4-6 mm; Season: Spring -- Fall.

a. male
b. female


6. Baetis tricaudatus.  Size: 5-8 mm; Season: Winter -- Spring.

a. male
b. female



7. Heterocloeon amplum.  Size: 7-9 mm; Season: Winter.

a. male



b. female

8. Heterocloeon curiosum.  Size: 6-7 mm (females larger than males); Season: summer.

a. male

b. female

9. Heterocloeon petersi.  Size: 7-8 mm; Season: Summer.

a. male



10. Iswaeon anoka.  Size: ~ 4 mm; Season: Summer.

b. female


11. Labiobaetis propinquus.  Size 4-6mm; Season: Spring through Fall.



12. Plauditus dubius.  Size: 3.0-3.5 mm; Season: Spring.

a. male
b. female
_______________

Entries to follow on Spiny Crawlers (Ephemerellidae) and Flatheaded Mayflies (Heptageniidae).  Photos for the families Ameletidae, Isonychiidae, Leptohyphidae, Caenidae,
Baetiscidae, Leptophlebiidae, and Ephemeridae will be combined in one entry.

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