REPLY: Moles and other Geophyte predators
Fri, 30 Dec 2005 09:47:33 PST
In a message dated 12/30/2005 12:12:56 AM Pacific Standard Time, writes:
We had a serious mole problem in our nursery beds which we have almost solved 
with an innovation that was not mentioned in any of the correspondence.  We 
came across two varieties of battery powered commercial mole deterrents which 
work by making sporadic sound impulses which moles find intolerable.  The 
impulses are nearly inaudible to humans, but have kept the moles out of our beds 
for this entire season.  They have an effective range of about 4 meters around 
the instrument.  The instruments are inserted into the ground to a depth of 
about 20 cm.  The cost of batteries was a factor that we overcame by using 
rechargeable batteries.  I believe these deterrents also come in versions that use a 
small solar panel, which would be ideal but these are not available in South 
Africa at present

We have found that Eucomis, Scillas and Ornithogalums are immune to mole 
predation, and to virtually all other insect and fungal pests, but they do not 
keep moles from eating adjacent palatable species -- the most susceptible of 
which are some of the amaryllids and Irids - especially Amaryllis belladonna and 
Cybistetes longifolia and Watsonias of which we have lost many to moles.

I wonder if we're talking about the same thing?  Here in the USA, moles 
(Talpidae sp.) are carnivores and consume only insect larvae/adults, annelids and 
similar.  They don't eat plant material.  Pocket gophers (Geomyidae sp.), on 
the other hand, are notoriously gluttonous diners at the geophyte smorgasbord 
and can readily decimate most geophytes, especially those with 
cormous/tuberous/rhizomatous storage organs.  Moles don't eat geophytes but their tunneling 
provides easy access to the larder for those animals that do, in particular, mice.

I think it is fairly widely accepted that gophers (may sample but) don't 
consume daffodils (an amaryllid) but they will certainly move the bulbs about (or 
destroy them) with their tunneling.  This may be due to the raphide-shaped 
crystals of oxalic acid in the tissue that cause mucous membranes to swell when 
ingested.  On the other hand, for some reason, they can and will readily 
consume hyacinth (the H. orientalis hybrids) bulbs.  They may also consume other 
tunicate bulbs, e.g., A. belladonna; I have no experience with these.  Bill Welch 
may have some firsthand experience with these bulbs and gophers, though.

I have used these vibrating devices in the past, but no longer do for the 
simple reason that they don't work!  They are marginally effective when the soil 
is undisturbed and solid, i.e., in plantings that have been down for at least 
a year.  They are totally ineffective in disturbed soil, i.e., soil worked up 
and planted -- the very place where I need something to keep the moles and 
their tunneling at bay!  They will happily tunnel right next to the device in 
disturbed soil.  For this tool to be at all effective, the soil has to be solid 
and wet and the device firmly lodged in the soil to permit the vibrations to 
travel through this medium.  The manufacturer's claim that one device will 
effectively "patrol" half an acre is ludicrous!!

I have been woefully ineffective at trapping these burrowing pests and have 
resorted to a Warfarin-containing gel that is supposed to taste like 
earthworms/grubs to control moles.  It does require care and skill in placement, 
however, to be consistently effective.  And I've been successful with carbon monoxide 
to control gophers.  Again, one has to be certain that one is treating an 
active run for it to be effective.  

Dave Karnstedt
Cascade Daffodils
Silverton, Oregon  97381
Cool, wet Winters and hot, dry Summers

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