Fly Fishing for Trout Home
User Password
or register.
Scientific name search:

> > I.D. ing bugs

FISHN50 has attached these 7 pictures to aid in identification. The message is below.
View Full SizeView Full Size (4.9X larger)
View Full SizeView Full Size (4.9X larger)
View Full SizeView Full Size (4.9X larger)
View Full SizeView Full Size (4.9X larger)
View Full SizeView Full Size (4.9X larger)
View Full SizeView Full Size (4.9X larger)
View Full SizeView Full Size (4.9X larger)
FISHN50August 25th, 2011, 11:50 pm
Metuchen NJ

Posts: 5
I want to thank all of you for I.D. ing the last 2 bugs. Like I said in the post I'm doing my first invertebrate study of a stream here in NJ that recently had a lot of stream work done on it. I want to get a count & an idea of it.s health & plan on continuing to do the sampling in different sections of the river in the next few yrs.
I can tell a mayfly from a caddis or stonefly but run into problems going any further on the I.D. I picked up a camera & it takes some pretty good macro photos so I intend on photoing most of the collected bugs. I also got a cheap digital microscope on E-Bay & will be using that as I get going.
This site is amazing & I want to thank you Jason for all the work you put into it. I look at it as a valuable resource & with your help & the rest of you fine fellow's help I'll be able to get most of the bugs I.D.
I have some more photos to post & would appreciate your further help.
If this is too much to ask just ignore my posts & I'll get the message

TaxonAugust 26th, 2011, 2:00 am
Site Editor
Royse City, TX

Posts: 1350

Ignore you? Never!

1) Waterpenny beetle larva
2) Isonychia mayfly nymph
3) Isonychia mayfly nymph
4) Acroneuria stonefly nymph
5) Acroneuria stonefly nymph
6) Unknown caddisfly pupae
Best regards,
Roger Rohrbeck
EntomanAugust 26th, 2011, 4:02 am
Northern CA & ID

Posts: 2604
Hi Neil -

The mayfly nymph photos are most likely Isonychia bicolor (Leadwing Coachman). Though there are other species, they are less common. They are all excellent swimmers.

The stoneflies belong to the Perlidae family and are probably Acroneuria abnormis (Common Brown Stonefly). The top one has molted recently, which explains the lighter color.

Any determination of the caddis pupa in the next photo would be pure speculation on my part (though I have my suspicions). Closeups of the frontal view head, dorsal abdominal, and anal processes would assist in determining the family, but to get to the genus level you will probably need to put the specimens in a covered container after shooting them to see if they will finish the emergence process. Then you can photo them as adults.

The last photo looks to be Maccaffertium mediopunctatum mediopunctatum, one of several Summer Cream Cahills (see edit). It was formerly classified as Stenonema nepotellum. By either name it is still one of the clinger nymphs of the family Heptageniidae.



BTW - That's a scud you have up in the corner of the caddis picture.

Edit: To correct the record, a recent conversation with someone I consider expert on photo identifying eastern mayfly hatches pointed out that the shape and number of posteriolateral projections (spines along the sides of the abdomen) precludes my suggestion and that this specimen is probably either M. modestum or M. ithaca. Between the two it's most likely the latter. Both are also Summer Cahills and pale as duns, so that part of the entry remains valid.
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman
FISHN50August 26th, 2011, 3:49 pm
Metuchen NJ

Posts: 5
Thanks guys

CrenoAugust 26th, 2011, 9:07 pm
Grants Pass, OR

Posts: 305
There are two caddis pupae in fig 6. The large one looks like a hydropsychid and the wing pads are black enough that is likely you can determine the species with a little work. You will need to carefully clear the abdomen (I use the KOH method) and then compare the private parts to figures in the literature.

The small one looks like a philopotamid. You should be able to determine genus just comparing it to the literature but maybe not species.

If ya want help just let me know.


Quick Reply

You have to be logged in to post on the forum. It's this easy:
Username:          Email:

Password:    Confirm Password:

I am at least 13 years old and agree to the rules.

Related Discussions

TitleRepliesLast Reply
Re: Probably Acroneuria lycorias
In Acroneuria abnormis Stonefly Nymph by GONZO
1Oct 28, 2008
Re: Better image
In the Identify This! Board by Btbo32
3Nov 20, 2017
by Wbranch
Re: 10 best Trout flies
In General Discussion by Bluefin
8Feb 25, 2009
by Hackleton
Re: Neoephemera
In the Identify This! Board by CalebBoyle
2Mar 15, 2008
by Troutnut
In General Discussion by Wbranch
Re: Driving Home from Ithaca
In Fishing Reports by Willy
2Jun 19, 2007
by Martinlf
Several new specimens
In General Discussion by Troutnut
Re: Help with Mayfly identification
In the Identify This! Board by MItroutbum
5Jun 14, 2008
by Wiflyfisher
Re: Mature nymphs?
In General Discussion by Emerger
8Nov 16, 2007
by Taxon
Re: Emerging Isonychia nymph
In General Discussion by Troutnut
2Oct 7, 2006
by Troutnut