Currently viewing the category: "Bot Flies"
What's That Bug? does not endorse extermination

Subject: Larvae?
Location: Central MN
August 7, 2016 7:52 am
Hi, Bugman! What on earth is this, apparent, larvae? About an inch and a half long, VERY chubby, no ‘legs’. Looks like Jabba the Hutt! Black spotty body, found in a garage.
Signature: Confused naturalist

Rodent Bot Fly Maggot

Rodent Bot Fly Maggot

Dear Confused Naturalist,
This looks to us like the larva of a Rodent Bot Fly.  See this BugGuide image for comparison.

THANK YOU!!  Yes, I found that on your amazing website…..I refer to it often. Thank you for your quick response. I have never EVER seen this before…and I’ve been on a frenzy trying to figure it out. Now I can sleep…hehehehee! (Total bug nerd)
Kelly

What's That Bug? does not endorse extermination

Subject: Unknown bug
Location: Canada
July 15, 2016 5:15 pm
Hi there,
Wondering what this bug is… Found it in the grass. It looks sort of like a bumblebee but it only looks to have one wing on the back.
Signature: S.G

Rodent Bot Fly

Rodent Bot Fly

Dear S. G.
Many folks mistake Rodent Bot Flies for Bumble Bees.

What's That Bug? does not endorse extermination

Subject: Bug
Location: Florence, Mississippi
December 12, 2015 8:29 am
I found this bug in my house along with my dogs. I am concerned that it is some sort of parasite, but was not able to identify it yet. If you know what this is it would surely ease my mind and worrying.
Signature: In waiting Jamie Hancock

Rodent Bot Fly Pupa

Rodent Bot Fly Pupa

Dear Keith,
We believe this is a Rodent Bot Fly Pupa, an internal parasite that is usually very host specific.  Since you found it in the home, we are surmising the host may have been a mouse or rat.

Rodent Bot Fly Pupa

Rodent Bot Fly Pupa

What's That Bug? does not endorse extermination

Subject: Large fly and spider
Location: New Hampshire
November 14, 2015 7:35 pm
Howdy!
I was camping in New Hampshire in the white mountains area. These two cuties were with us. One as a dinner guest and the other after a rain storm. Please help. I’m good at identifying most bugs (I actually wanted to be an entomologist ) but I was surprised by them.
Signature: Eric Barbasso

Rodent Bot Fly

Rodent Bot Fly

Dear Eric,
Your spider is one of the Orbweavers, and your large fly is a Rodent Bot Fly in the genus
Cuterebra.  According to BugGuide:  “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.”  We believe your Bot Fly is Cuterebra fontinella fontinella, and according to Bugguide:  “White-footed mice (Peromyscus leucopus) are the main host for this subspecies.”

Mr. Marlos,
Thanks for getting back to me. That’s what I thought as far the spider was concered. But, to know we have Bot Flys here is scary.
Thank you
Eric

Hi again Eric,
Though sightings of adult Rodent Bot Flies are not that frequent, based on the number of rodents with bots, they are not rare, and they are no cause for alarm.  The bots are not especially detrimental to the rodents and the Bot Flies do not trouble humans.

What's That Bug? does not endorse extermination

Subject: bug mystery in quebec
Location: my yard, near montreal and quebec city, quebec, canada
July 19, 2015 3:45 pm
hi there bugman. found a bug, couldn’t identify it, we’re curious if you can help us. it was pooping white/transparent goop, head upside down in the grasses of my yard. location: southern quebec, canada.
Signature: s+r

Rodent Bot Fly Ovipositing

Bot Fly Ovipositing

Dear s+r,
You images are a thrilling addition to our archives.  This is a female Bot Fly in the genus
Cuterebra, and she appears to be in the process of laying eggs, the “white/transparent goop” that you observed.  Rodent Bot Flies are parasites of rabbits, mice, squirrels and other rodents.  According to BugGuide:  “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.”

Rodent Bot Fly Ovipositing

Bot Fly Ovipositing

Jeff Boetner, Bot Fly expert, provides some information.
Hi Daniel,
Nice pics. This is a relative of your mystery FL bot from a week or so ago. But this one we can ID as Cuterebra fontinella fontinella. This is a nice shot of a freshly emerged female. The fontinella bots are known for the white rumps on the last segment of the rear end. This is a huge female, they can lay over 1,000 eggs in their short lives. Most eggs are laid in mouse runways or near burrows. The fluid you saw was likely because the female just emerged from her pupae (in the soil). Bots have no mouth parts or digestive tract so no need to poop. They have to store up all their energy they need as adults, by feeding as a maggot in the mouse host, and this one did a good job of that, judging by her big body size. This one is a specialist on white-footed mice, Peromyscus leucopus. This species is our most common bot, yet not found as often as you would think. I have trapped over 200 mice per hectare*. in our plots in MA, and sometimes 80% will have 1-2 bots, so you would think there would be huge numbers out there. And yet many entomologists I have met, have never seen one in the wild. So consider yourself lucky…(or unlucky if you are a white-footed mouse).
Jeff

*a hectare is approximately 2 1/2 acres.

Thanks a lot for the quick answer, dude/dudette(s)! We weren’t expecting close to this quick of a response. I’ll be sure to bug you again for some more IDs (hohoho).
-Simon

What's That Bug? does not endorse extermination

Subject: Please indentify if able, Thank You
Location: Midwest, Minnesota. United States Of America
July 17, 2015 6:36 am
Sitting, right outside my backdoor. Enjoying a morning smoke before breakfast. This little guy, decides to walk across the tows of my shoe. Down onto a leaf in the grass. Kind of resembles a bumble bee. Only white and black. Instead of yellow, and the eyes shaped different. Which leads to my curiosity, if it may be a different species possibly.
Signature: By the person/ individual who is willing to kindly help answer my question 😉

Bot Fly

Bot Fly

Dear person/individual,
This is a Rodent Bot Fly in the genus
Cuterebra, and members of the genus are often very host specific.  Rodent Bot Flies are external parasites on mice, squirrels and rabbits.

What's That Bug? does not endorse extermination