From: ketchum@cs.montana.edu (Steve White)
Newsgroups: rec.hunting
Subject: Re: Southeastern Ohio Squirrel Hunting
Summary: rodent bot flies
Date: 9 Oct 92 14:05:48 GMT
Organization: Dept. of Computer Science, MSU, Bozeman Mt 59717
Originator: hunting@osnome.che.wisc.edu

In article <1992Oct8.110340.9394@doug.cae.wisc.edu> gmk@falstaff.MAE.CWRU.EDU (Geoff Kotzar) writes:
>In article <1992Oct1.084910.27831@doug.cae.wisc.edu> smash@oucsace.cs.ohiou.edu (Scott Mash) writes:
>>.........  So far I have got 17 and only 3 have
>>had wurbles (sp?) and one of those 3 had 6 (yes 6) wurbles, he looked
>>like a rodent tumor!
>>
>
>What are "wurbles"? I have never heard of them before. What do they look
>like and what do they mean relative to eating the critters? Is this the
>same malady that rabbits get?
>
>geoff kotzar
>

I started out on this long spill on what I remember from H.S. ag. on 
bot fly larvae. Then I decided to read my vet manual "The Merck Vet. Manual"
5th edition. Then I changed my long spill making it longer. Then when I 
was done I found out that the cattle bot is not the same one that
infects rodents. So read about the cattle bot and then the rodent bots or
hit "n" now.
_____________________________________________________________________________

It's warbles; like cattle commonly get. Also called cattle grubs, Ox warbles, 
and bots. The adult fly is called the heel fly, gadfly or bomb fly.

The adult fly lays several eggs on hair on lower portions of the animal.
When the egg hatches (in 2 to 6 days) the little critter climbs up the hair 
and to the skin and bores a hole in which it climbs in. The larvae have 
been found in about all parts of cattle so no one (except God) is quite 
sure where they go. They secrete a proteolytic enzyme that breaks down 
tissue forming food for them and they move ahead into the void. They 
generally end up in the back of the animal. By now they are about 
15mm x 2mm. Here they secrete more slime, that bores a small hole in the hide,
that allows them to breath, and stay for 40-60 days while molting twice.
By then they have grown to the be about the size of the distal section of 
your finger ( or 25mm x 8mm ). Then the larvae falls out on the ground. 
Then it bores into the soil where it stays for 1 to 3 months. It then emerges
as an adult fly and starts the hole process all over again. The adult doesn't
eat and lives for maybe a week. If it's lucky it breeds, lays eggs and dies.
(What a terrible life. Kind of like most aquatic insects found in trout waters.)

My vet manual says that only bovines (cattle and bison) are commonly affected
with the Hypoderma lineatum and H. bovis larvae. Although recently more cases
have been showing up in horses. Humans have also been known to get them.

We used to remove the bot larva from a bovine by finding the larvae and then
putting the mouth of a Coke bottle over the hole. Then you would strike the
end of the bottle with the palm of your hand and the bot would sometimes pop
up into the bottle. Or you could squeeze them out like a large (sic) pimple.
Be careful to keep your face off to the side!

Okay now we're all grossed out. I think that the worst problem with the 
bots and cattle is that they put holes in the hide, thereby reducing the
value of the hide for leather. If you look carefully at hole cowhides some-
times you can see these holes in the area of the back (especially if the 
hide is from down south where I think that the problem is worse.) After,
consulting Merck I need to add that a carcass that has bots is generally
penalized in value. A single animal may have 1 to 300 larvae.

There is an insecticide that one pours on the backs of the infected animals
soon after the heal fly season is over.

Rodent Bot Flies (Cuterebra ap.)

The life cycle doesn't differ much from the cattle bot fly, but here goes..
Females usually deposit eggs in the burrows of wild mammals during the summer
months. Timy larvae (1mm length) hatch and wait for contact with an animal
in the burrow. Larvae penetrate the skin of the nose and mouth and make their
way to various subcut. locations in different hosts. The route of migration
is variable. The maggot may reach 25mm in length and 10 mm in dia. Larval 
development takes approximately 1 month, after which the maggot exits from
its subcut. location to pupate in the soil. They mature in about 300 days. 
Adult flies live about 2 wks and are said to lay up to 2,000 eggs/female.

The usual hosts are burrow-dwelling mammalis such as mice, chipmunkcs, 
rabbits and squirrels. Dogs and cats sometimes become infested, presumably
>from investigation of such burrows. Lesions are found most often under the 
skin of the neck and chest during late summer and early fall. Constant 
licking of the chest area is frequently the most obvious clinical sign
in cats.

I have trapped white-footed (common field mice) in S.TX that have had a few 
of these bots in them. They are quite noticeable. The mice always seemed to
be in fine shape and not bothered other than looking funny.

Now you know all that you ever wanted to know about heel flies...
							   _________________
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  Steve White								     |
  INTERNET : ketchum@cs.montana.edu					/___/   

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