Re: About those Piranha Bugs - and more vileness

----- Original Message -----
From: Brian Bilderback <bbilderback@hotmail.com>
To: <gzg-l@csua.berkeley.edu>
Sent: Saturday, January 12, 2002 12:48 AM
Subject: RE: About those Piranha Bugs - LOOOOONG

Beth.Fulton Wrote:

SNIP
There'd still be a top end to the mass of bugs sustainable in a given
area,
wouldn't there be?

>Alternatively the mounds may only be temporarily inhabited, the Piranha
>Bugs
>may stay permanently on the move like Army Ants which do number in the
>millions and can strip a horse. So the Piranha Bugs may move from mound
>complex to mound complex as they strip whatever is in their path.

True enough, and very likely.  But it still suggests that there aren't
going
to be multiple mounds each with it's own high population of bugs within
one
area.  That's the impression I got from the first description, and the
one
with which I took most issue.

>Yet another alternative is that the Piranha Bugs are actually just one
>stage
>in the life cycle (so sort of the same argument as above, but a life
stage
>not a caste), and once they've "eaten their full" so to speak they
>reproduce
>and die. Thus relieving pressure on the local surrounds until that life
>stage is reached again.

True, but this still would support the concept of a highly territorial
bug,
since they're STILL not going to want other colonies around during the
development of the next stage of bugs....

>Yet another alternative is that the ants take the opportunity of the
food
>presenting itself to do a raid and save them the effort of going to get
it
>-
>much the same way as Army ants will forgoe their dawn raid if a large
food
>source presents itself at the door of their bivouac.

I like this.  Like you, I see them more as flying army ants than as
beeish
animals.  But I still think there's got to be a limit to the number of
them
that any given area can sustain....

>
>OK better stop now before I go through too many alternatives and make
you
>want to release said bugs on me ;)

Don't stop now, the more you suggest, the more cool ideas I get for
future
use. :-)

Brian

[Rob says]
The limit to the number of Piranha Bugs could be very high if e.g. they
relied on migrating herd animals as a food source- think of those
African
rivers with large populations of LARGE Nile crocodiles, supported by
annual
herbivore migrations attacked at a choke point. A relatively small mass
of
insects makes a big, big swarm- a nitwit of my acquaintance, an
entomologist
yet, thought that the 2 litres [2 litres !!] of blowfly maggots he'd
obtained to feed to mantis nymphs had all died, so he just left them in
the
incubator room.  When I went to investigate, I opened the door and saw a
2
metre high vortex of howling blowflies swirling right in front of me, as
the
damn things had just emerged from their pupae. I can see them now.

Earthly arthropods can have resting stages which can last _years_, so
the
Piranha Bugs could perhaps be similar.	Another lab in the place I used
to
work studied tick-borne diseases
[favourite quote from Greek visiting student: "Our strain of Crimean
Congo
Haemorrhagic Fever doesn't infect humans" "Oh, how do you know?"  "We
work
with it on the bench and noone's gone down yet..."]
and bred some huge and truly ghastly ticks that could do 10 years
between
meals.

A possibility is that the mounds are mud structures in which the PBs
rest-
only a migrating herd of Buffaloids can break the mounds, and that
triggers
the feeding behaviour of the PBs. The PBs therefore needn't be
territorial,
in the sense of defending a territory- the victims have just acted like
food
at feeding time.

Rob Paul