Dear Robert,

One of the first questions is whether you are 100% sure that you are dealing
with Euglandina rosea in that Central American country? Numerous species of
Euglandina are living in Central America.

Rumina is not a native snail in Israel, but is known from at least two
archaeological sites in Israel: Caesarea and Apollonia (Tel Arsuf). At both
localities it is now extinct, but thousands are still laying around. At both
sites it was introduced at a very early stage of civilization. However, to
interprete its occurrence at Caesarea and Apollonia as early trials of
biological control of other snails? I do not think so. Do not forget that if
Rumina (whether decollata, saharica or paivae) does not find a partner in
order to mate then self fertilization takes places i.e. a single snail
inadvertently transported from one place to an other can start in principle
a new population.

The use of Rumina in the biological control of pest snails like Cornu
aspersus (formerly Helix aspersus) in California is a relatively new method
(see the numerous papers by T.W. Fisher and R.E. Orth), but in my opinion
full of dangers. Rumina prefers to prey on worms and snails but if none are
available it feeds on plants and their fruits as well. With other words it
can turn also into a pest snail.

There is an additional danger: if Rumina spreads into a natural habitat it
will not leave the endemics unharmed! Similar events we have seen already
with the introduction of other snail eating predators on numerous Pacific
islands: the endemic species were predated upon and Achatina multiplied
almost unharmed.

Biological control is an excellent method but with pest specific predators
and parasites. If the predator has killed  the target pest species it will
starve soon afterwards by malnutrition.

Best regards,

Henk K. Mienis
Curator of the National Mollusc Collections at the Hebrew University of
Jerusalem and the Tel Aviv University, Israel
and Insect and Plant Pest Consultant in Field Crops, Netzer Sereni, Israel

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----- Original Message -----
From: Robert J Lichtenstein <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, February 21, 2002 10:15 PM
Subject: Rosy Wolf Snail Question


> Hello All,
>
> A number of you were very helpfull some months ago with my querries in to
Pomacea f.. Here's hopeing someone out there can offer up some ideas on
something a little different.
>
> I have a question on the use ofthe predatory molusk  Euglandina rosea (F
Erussac1821) as an agent of biological pest control in ancient Mesoamerica.
I know that E. rosea has been used for this purpose in modern times (often
with unfortunate side effects).
>
> 1. I have encountered the shell of E. roseus in archaeological contexts in
northwestern Belize Central America. As live specimines are often found in
the surrounding modern vegitation, I have always assumed that the shells I
was finding were intrusive in nature.
>
> 2. Recently I read an article by Pinto-Guillaume in the January volume of
hte Americam Journal of Archaeology, where it is proposed that the Romans of
the first century B.C. to first century A.D. may have used Rumina decolata
(Linne 1758) as a form of biological past controll in villa gardens.
>
> 3. My question becomes could the ancient Maya of Central America have used
the rosy wolf snail (E. rosea) as a biological control in their kitchen
gardens? In other words maybe some my pesky "intrusive" terrestrial snail
shells are not intrusive after all.
>
> Any comments, notions or ideas would be greatly appreciated.
>
> Thanks to all,
>
> Bob,
>
> Robert J. Lichtenstein R.P.A.
> [log in to unmask]
>