What's That Bug? does not endorse extermination

GIANT fly
Location: Dallas, TX
October 17, 2011 9:53 pm
I’ve lived in Dallas, TX for 40 years and have never seen such a thing. Found today on our hydrangea plant. It has a fat head, thorax & abdomen, is mostly black with awesome horizontal red stripes across the top of its huge eyes, has white fuzz between the thorax & abdomen, and it’s wings fold in a crossed fassion, unlike most flies. Its legs are just like a common house fly (only larger) and it rubs them together and walks/behaves like a fly. When it flies it sounds loud like a bee. It’s about an inch long!
Signature: Grasshopper

Rodent Bot Fly

Dear Grasshopper,
This amazing fly is a Rodent Bot Fly in the genus
Cuterebra, but alas, we don’t recognize the species.  It doesn’t seem to match any of the species posted to Bugguidewhich describes the life cycle as:  “Females typically deposit eggs in the burrows and ‘runs’ of rodent or rabbit hosts. A warm body passing by the eggs causes them to hatch almost instantly and the larvae glom onto the host. The larvae are subcutaneous (under the skin) parasites of the host. Their presence is easily detected as a tumor-like bulge, often in the throat or neck or flanks of the host. The larvae breathe by everting the anal spiracles out a hole (so they are oriented head-down inside the host). They feed on the flesh of the host, but only rarely does the host die as a result.”

Rabbit Bot Fly

GIANT Fly – much better picture!
Location: Dallas, TX
October 17, 2011 10:30 pm
Please refer to my previous submission today.
thanks
Signature: Grasshopper

Rabbit Bot Fly

We will add this to the posting we already created for your amazing beautiful Rodent Bot Fly which we now believe to be a Rabbit Bot Fly, Cuterebra buccata, based on photos posted to BugGuide.

Wow, that is awesome!  Will definitely comment back!  Thanks Daniel.
Greg Hotchkiss, aka Grasshopper (my best friends actually have called me that since college)


What's That Bug? does not endorse extermination
Location: Texas

11 Responses to Rabbit Bot Fly

  1. equalrights4parasites says:

    Grasshopper,
    Really nice bot photo. Your species is a rabbit bot, not a rodent bot. This is Cuterebra lepusculi (likely closely related to C. buccata, and I can see why whatsthatbug had problems with ID). The key to these two species, is having the red line in eyes (which both C. lepusculi and C buccata have, although often C. buccata has a broken line looking like two red dots). But C. lepusculi when looked down at from above has the classic white U shape outlining the body. Sometimes this line is faint-almost black, but yours is a classic thick white U. This is likely a male by the spacing between the eyes when seen from above, female eyes are farther apart.
    There are only about 14 male specimens of this fly in museums (for some reason females are more often collected in this species- at least 60 in collections around the US.). If you collected this- and still have it, I would love to talk to you about it. I am working on making a better key for bots, and also doing dna work on them for a key to immatures. I would donate it to the Smithsonian collection when I was done with it. It is not really a “rare” fly, in the sense that its range is from WA to SD south to CA over to TX, and at least one record from Mexico. It is a western version of C. buccata. It is rare in collections because adults are short lived (live maybe a week, because they can’t feed as adults), plus if you find one in a rabbit, they have to be reared in soil for almost a year. So very hard to raise adults. This species uses primarily cottontail rabbits, Sylvilagus nuttallii, as a host, but may also use the desert cottontail, S. audubonii as a host. Bots would be seen as lumps under the skin (in about 1 month from now), usually on the back or behind the front legs. Can be multiple bots per host. Not real fun for the rabbit, but not likely to harm the rabbit, mostly it is very painful.
    Please post your pics on BugGuide.net as well. We do not have pics of this species on that site and pic of the male is especially nice. Thanks for posting. I was excited to see these pics!!! Feel free to contact me with questions, and let me know if you still have it.
    Very nice find! I am sooo jealous.

    Bugs and kisses,
    Jeff Boettner
    Plant, Soil and Insect Sciences
    UMASS-Amherst
    boettner@psis.umass.edu

  2. Grasshopper says:

    Hi Jeff, wow, thank you for your wonder comment! I knew we had found something special, but had no idea just how special! God has truly designed the most amazing creatures, and I really love this one (even as unappetizing as its reproduction cycle is). And guess what, we have none other than a Cottontail nest right underneath the hydrangeas where we found this Rabbit Bot! I would love to assist you and will email the photos I took while it was alive (it died today). I just pinned it trying to preserve it, but will have to convince my 8-year-old son to let it go for a higher cause (he started a collection earlier this year with some pretty nice bugs). Will be in touch!

    Greg Hotchkiss / Grasshopper

  3. equalrights4parasites says:

    Hi Greg and son,
    So glad you collected this one. A woman and her daughter found C. mirabilis (see BugGuide for her pics), which is only the third specimen ever seen of that species-(the male has never been found yet)! Hers is a parasite of black tailed jackrabbits but all three known specimens have been found only in a small part of NM. Anyway her daughter had it as a pet and when it died she buried it in the yard with flowers. Maybe the best parasite burial ever. But I may never find that species in my lifetime. I did fly out to meet them and saw where they found it. We spent 10 days looking for it last year but to no luck.
    So at least your son didn’t bury this one…yet. Have him email me and I will try to work out a deal for the future entomologist 🙂
    Keep an eye on the cottontails. You may find a female bot hanging around as well. Males of some bots do lek behavior, ie males will defend a good site, and play king of the hill to defend it against other males, and females will mate with whichever bot is holding it when she arrives. Your hydrangea might be the lek post with the male trying to show a female where the host is? Most bots lek behaviors/mating between 9 am and noon. Females may show up even late in the day, if already mated. But you know you have bots in the area and the host. So you might find more? No leks have been described for this species yet. Often leks are on hilltops or some prominent feature. But in your case they could be mating at the rabbit den? Hard to know. Worth keeping your eyes on it.
    Often bots emerge in good numbers after a rain event. I know it hasn’t rained much in TX all year. So especially watch after the next big rain or if you had a rain in the past week.
    Bots might show up on rabbits as large lumps under the skin in about a month from now. Takes a while for the mating to be over, the eggs to hatch, and for larva to get big enough to notice under the skin. Let me know if you see infested rabbits. I might want to try to come down. Also keep your eyes on roadkill rabbits. I have pulled bots out of roadkill and reared them, although the bot has to be nearly done (ie large) in order for this to work. But for my work, even immatures would work for dna.
    Do email me (with your son) and will see if I can win him over 😉 I will make it well worth his time.
    Great find. Keep on hunting.
    Thanks for the fun post. Nice to see this one.
    Jeff

    boettner@psis.umass.edu

  4. Could these large lumps on a black tailed jackrabbit be from the bot fly mentioned above?
    http://www.pbase.com/arlon/image/163924106

  5. Varietypak says:

    Curious about the size of the bumps you mention the bots show up on rabbits as “large” lumps – is that the size of a pea?
    When my puppy first came to me , he had a lump on his side – noticed it was getting bigger and when it was about the size of a pea, I took him to the vet. The vet was very excited with the “find” of a fly larva – probably a bot?
    Thank you!

    • Jeff Boettner says:

      Hi Varietypak,

      They can range from the size of a pea when starting out, to almost 2 inches for the rabbit bots. Not common in dogs and cats but if they eat a mouse with a bot the bot may try and use the new host. Or if they lick a plant with an egg on it. But most bots are very host specific.

  6. Varietypak says:

    Thank you for the information, Jeff Boettner!

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