Tuesday, June 8, 2010

Fishflies: A New Find For Me!

I found these two locked together on the railing of a small bridge in the woods the other day.  I was on a walk with my husband around 9:30 or so in the morning. Realizing that my cell phone photos would not suffice, I returned to the bridge a couple of hours later with some proper camera gear.  Lucky for me, they hadn't moved a bit.  When I had initially spotted them on the bridge, I had thought it was one insect (I thought it was a dobsonfly).  It wasn't until the two separated hours later that I realized that there were two of them and that they were mating.  I had myself a good chuckle over that.  Luckily no one passed by at that moment, as they would have seen me talking to myself and laughing.  I guess that would really put the "Nut" in "Nature Nut Lady" though!!

So, I don't know much about fishflies.  They do look a lot like dobsonflies (which I have only seen in books), and are actually in the same family as them (Corydalidae).  In these photos, I believe the larger of the two is the female.  The fishfly to the right here, I believe, is the male.  Once the two completed mating, the male quickly flew off.  Typical.  I  also believe that these are dark fishflies from the Nigronia genus. 

Rear view of what I think is the female.  Perhaps an egg or egg sac?

(You can click on the pictures to get a better look!)

Head Shot of the Female

Juicy Tidbits:
  • Dark fishflies are noted for having dark wings with varying white markings on them
  • Found near streams
  • Apparently adults do not feed
  • Fishfly larvae live in moving waters, such as narrow clear streams or small rivers. They feed on small aquatic insects and help to keep black fly larvae in check. 
On my walk tonight, I noticed a couple more fishflies along the path in the woods.  They are not very strong fliers it seems.  Apparently adults are both diurnal and nocturnal.  Seen flying near streams by day, but attracted to the lights at night.


Kaufman's Field Guide to Insects of North America, page 224.
National Audoubon Society Field Guide to North American Insects & Spiders, pages 519 & 521.

Websites Used for Fishfly Facts:

http://www.bugguide.net/ , specifically,  http://bugguide.net/node/view/4156 

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