Thursday, April 26, 2012

My first flying odonates of the year (in Louisiana)

It’s been a while since I have posted anything, but I’m on the road—currently in Louisiana, then in South Carolina next week for the Dragonfly Society of the Americas annual meeting, so I thought I’d share a few photos while traveling.

I had not yet seen any adult odonates at home in the Pacific Northwest, so my first of the year were at Avery Island, Louisiana—a salt dome protruding out of the marshlands and bayous where the world supply of Tabasco hot sauce is produced. Also located here is the Jungle Gardens, a botanical garden and bird sanctuary established by the McIlhenny family with plenty of alligator-occupied ponds and odonates. The odonate diversity was not great, but some are species that do not occur in the Northwest. Below are several species photographed at the Jungle Gardens a couple days ago.

Male Eastern Pondhawk (Erythemis simplicicollis), a very abundant species here. Very similar to our Western Pondhawk (E. collocata) which some may argue is the same species. The very pale cerci at the tip of the abdomen are characteristic of Eastern males—at least over most of its range, and is not typical of Westerns. Here's the Eastern Pondhawk range map at OdonataCentral.org.
Female Blue Dasher (Pachydiplax longipennis)—what appears to be the second most abundant species around. This should look familiar to many people in the Pacific Northwest.

Male Rambur's Forktail (Ischnura ramburii). This primarily southern species does not make it into the Pacific Northwest, but it is found as far west as southern California (also introduced on the Hawaiian Islands). Map.

Another Rambur's Forktail, but this is an immature female with an impressive clump of water mites on the side of the thorax. See that little orangish-brown spot on the wings near the thorax and right above the abdomen? That appears to be a ceratopogonid midge—another ectoparasite of adult odonates. These latch on to the wing veins and feed on the fluids within. It must be quite a ride while the odonate is flying! Ceratopogonids, at least the ones that parasitize odonates, are primarily tropical—I've never noticed one in the Pacific Northwest.
Male Fragile Forktail (Ischnura posita). These are tiny, inconspicuous little things lacking the blue spot near the tip of the abdomen which is characteristic of most Ischnura. This species is widespread in eastern North America, and is not found west of the Rocky Mountains (except in Hawaii where it is not native, of course). Map.

8 comments:

  1. Do you happen to know which ceratopogonid it is that infests zygopterans? I'm trying to hunt down more info on them and I'm having a hard time finding anything!

    ReplyDelete
    Replies
    1. Sorry, Chris, I am really clueless about these things. I haven't been able to dig up much on them either.

      Delete
  2. Swing by the Missouri Ozarks on your way back from South Carolina. We've got PLENTY of room!!!!

    ReplyDelete
    Replies
    1. I'll see if the plane has any parachutes on board as I'm flying over...

      Delete
  3. Are those mites really that color, or is that the lighting? Very differet from the black or red one's I'm used to.

    Also, I find it interesting when the Eastern Pondhawks elevate their pale cerci like flags...haven't been able to photograph it yet, but I'll be working on it when I go back to IL this Summer (I hope).

    ReplyDelete
    Replies
    1. Yes, those mites really were that color. I've seen greenish ones before, but I can't remember off the top of my head if I've seen them in the Pacific Northwest or just elsewhere.

      Delete
  4. I think it's really cool that you came to Louisiana. I live north of New Orleans and have always enjoyed watching Dragonflies. I love how you can put your hand out for them and they'll come land on you, which I just did a little while ago (a giant blue one). That sparked me to come look on the net about them and found your blog.

    I was wondering if there are any types of decor you can put in your yard to attract them, like hummingbirds? Not that there's too much of a shortage of them or anything.

    ReplyDelete
    Replies
    1. The only way to really attract odonates to your yard is to put in a pond, and you'll likely get a couple species laying eggs in it. If you do want a pond for odonates, you'll maximize it's diversity of species by not putting fish in there.

      Delete