Subject: Re: Boric acid and ants
From: wtmorgan@pilot.msu.edu (Bill Morgan)
Organization: Michigan State University
Date: Sun, 14 Sep 1997 13:44:56 -0400
Message-ID: <MOD$970914.25154@rec.gardens.ecosystems>
References: <MOD$970912.21692@rec.gardens.ecosystems> <MOD$970913.1711@rec.gardens.ecosystems> <MOD$970913.8415@rec.gardens.ecosystems> <MOD$970913.15268@rec.gardens.ecosystems>


In article <MOD$970913.15268@rec.gardens.ecosystems>, Jim and Sheila Reed
wrote:

> Carol Moholt wrote:
> >
> > In response to my question about a boric acid/sugar/water recipe for ant
> > control, Bill Morgan wrote:
> >
> > > First of all, you want to make sure you are poisoning only those which are
> > > actually pestiferous, and not those which are harmless or beneficial.
> >
> For Bill Morgan--
> 1. I'd think any ant that invades the house is a pest--here in S.
> Florida the biggest problems are fire ants, plus ghost ants, pharaoh
> ants, black pavement ants and carpenter ants.

Carol indicated ants in both house and garden. Her original post did not
indicate whether or not these were the same kinds of ants, nor did it
indicate what problems,if any, were caused by the ants outdoors. Also,
there are undoubtedly other species of ants around, and it is always good
pest-control practice to limit the killing to the narrowest possible
spectrum.

As to whether or not ants In a house are pestiferous, I consider that to be
a product of their numbers and activities. An occasional straggler running
around is not really enough (IMO) to warrant any action. If there are six
lane highways of pharaoh ants through the house, you would be foolish not
to take action. If there are a few carpenter ants cruising through the
house, they may or may not represent a problem warranting control. If they
are nesting in the wood of the house,they are symptomatic of structural
damage that needs to be attended to.

> We still spray inside to keep ants from being a problem, but do not
> spray our lawn or gardens. Can you define which ants you think are
> harmless or beneficial? Do you have a reference or source to cite?
Ants engage in many types of activities, some beneficial, some harmful. It
isn't the case that one species is always pestiferous and another always
beneficial. Many times, it depends on the situation as the same species may
have a mix of behaviors, some beneficial and some pestiferous.

Perhaps the main beneficial impact of ants is that many species work and
aerate the soil. On a world scale, they are about as important as
earthworms in this regard. In the tropics, they are somewhat more
important, in temperate regions somewhat less so (though still quite
valuable even in the temperate zone). Many of these are ants you seldom or
never see: tiny ants which live most of their lives underground, or which
are so small you'd never notice them aboveground. You'd be surprised at the
numbers and diversity of ants present in a cubic yard of good soil. There's
a small, yellow species that I only encounter once a year, when I
double-dig the garden. Most people probably have never seen these: that
does not mean that they are not around, or that they are rare, just that
their habits are unobtrusive. (I'm assuming that they occur more widely
than in my little garden plot...)

Another beneficial activity of ants is predation. Not all ants are
predators, but many are. (They are essentially wingless, social
ground-dwelling wasps, after all.) Among the predators, some are
generalists, feeding on a great variety of prey (African driver ants), some
are specialists, feeding on only a single family or order of prey.

There are some large mounds of a species of Formica in my lawn which I
leave untouched simply because I know they act as generalist predators in
the garden (and because I'm not that picky about the lawn). These same ants
also tend treehoppers on the sunflowers (much as many ants tend aphids),
but that never seems to harm the crop significantly, and having the
predators around is a great benefit. (BTW, they are also scavengers, so
they pretty much do it all...)

In natural ecosystems (and in semi-natural landscaping), ants also play a
role in planting the seeds of some plants. Many of the woodland wildflowers
(e.g., Trilliums) are planted primarily in this manner. Some plants are
more highly dependant upon this than others, but it is quite common. Many
ants also visit flowers for nectar, and are pollinators. In most cases they
are minor pollinators, but for some plants, certain ants are the exclusive
pollinators.

[snip Carol's lines]

> For Carol --
>
> My experience is that the aphids come first, and the ants come to
> collect the honeydew (which is also responsible for the sooty mold).
Realizing of course, that not all ants tend aphids; a distinction which
seems to escape some of the people over on the main garden group.

> Perhaps your ant problem on some ornamentals might lessen if there were
> other beneficial insects in place to clear out the aphids, or you took
> some other steps to get rid of the aphids. I think if you can remove
> the aphids and the honeydew they leave behind there'll be nothing there
> to attract these sugar-eating ants.
>
Ants are extremely diverse and abundant. E.O. Wilson is perhaps the
"two-legged ants'" greatest authority on the six-legged ants. Although not
all his books are intended for the general audience (and are therefore
expensive: that's the way the publishing industry works), if you are
interested in the topic, you might be able to find some of them in the
library. His "The Insect Societies" (1971 Bellknap Press of Harvard
University Press; ISBN 0-674-45495-2) isn't too terribly technical and is a
good intro not just to ants, but bees, wasps, termites and a bunch of "also
rans" that aren't quite social.

He has a more recent volume entitled simply "The Ants", but unfortunately,
I do not have a full reference to that. Perhaps someone else out there can
help me out on that....

Naturally, the problem species get more press: it is easier to find
literature on say, fire ants than on the little yellow guys (ok, gals) from
my garden. Problems get noticed and attract research in a way that
non-problems do not. That's just the way things work.

Regards,
Bill

--
Bill Morgan
wtmorgan@pilot.msu.edu
Center for Room Temperature Confusion