RE: monarch butterflies

There are milkweeds native to Africa planted at UC Botanical Garden, in
Berkeley, California, and migrating monarchs laid eggs on them one or two
years. The eggs hatched, the caterpillars chewed and went on to pupate,
but the Stellar and Scrub jays had a field day eating, picking them off
where they were attached to buildings. It seems that some milkweeds do
not have toxicity to protect the butterflies. I later learned that African
butterflies don't have mimic spieces as the monarchs of the western
hemisphere do.
Elly Bade

On Mon, 24 Jan 2000, Loren Russell wrote:

> 
> 
> On Tue, 25 Jan 2000, Randall, Rod wrote:
> 
> > Certainly a worthy cause but please be 
> > aware that a few species of Asclepias
> > (or  Gomphocarpus) are quite nasty 
> > environmental weeds that also impact
> > on pastures.  The plants are quite toxic 
> > and the latex sap can blind if it gets in your eyes.
> > The seed are produced inside rather 
> > attractive swan shaped pods, 
> > hence another common name, swan plant, 
> > and when mature sally forth on silken threads
> > all very pretty but highly invasive.
> > 
> > Caution is advised when considering planting 
> > these shrubs as over 20 species are listed
> > as toxic in the USA (by the FDA and University 
> > of Idaho) and several are listed as weeds.
> > They contain cardenolide type cardiac glycosides and
> > galitoxin that can poison cattle that inadvertently eat the seedlings 
> > amongst mouthfuls of grass.  
> > They are also common causes of child poisonings due to the sap
> > when children play with the flowers and pods
> > (Sally Wilson, (1997) Some Plants are Poisonous.  Reed Books)
> > 
> > We have a lot  school teachers ringing us up wanting to grow
> > swan plant to provide food for monarch butterflies, 
> > they know the plant is a weed but seem
> > to think it will be all right for thier purposes, 
> > and they still want to know where to get the plants from.  
> > Really frustrating for us to deal with these enquiries.
> > 
> 
> I believe Rod is writing from the experience of weed science in western
> Australia, and he may have non-indigenous Asclepias in mind...
> 
> It should go without saying that the responsible thing is to 1) plant
> local natives [on the Pacific slope of the US, this is usually Asclepias
> speciosa], or well-behaved garden plants like A.tuberosa.
> 
> A. speciosa is a native species here [Willamette Valley, western Oregon],
> and highly persecuted by agriculture, by road maintenance, and shopping
> malls. The few plants that survive to
> mature size are usually located by monarchs, and they have several other
> quite interesting insect customers -- all jewelled since the mikweed's
> toxicity is conferred on their consumers..
> 
> Last year, I participated with a number of native plant enthusiasts in
> salvaging some of  a large population of A.speciosa from commercial
> development, and in distributing seed to land-owners who wanted to
> re-establish the Willamette Valley as a viable area for migrating
> monarchs.  I don't anticipate a weed problem to develop, but in fact 99
> percent of the plant life the milkweeds will displace is non-indigenous,
> and plenty of it COULD hurt someone if they tried hard enough [see the
> Norse fable of the mistletoe arrow].
> 
> A number of native plants are listed as noxious weeds in the western US
> without much regard  to the actual problems caused -- which are often
> either non-existent or the direct result of overgrazing [cows, horses, and
> even sheep are not such fools as to consume alkaloid-bearing plants if
> there's anything else left toeat].
> 
> Although the monarch migration west of the Sierra/Cascade axis is not as
> spectacular as the eastern flyway, this ancient pattern deserves to be
> preserved, and it IS very threatened by suburban and agricultural
> development.
> 
> As to concerns with toxicity and corrosive sap, I should point out that
> milkweeds never seemed to be a problem with rural youth in the
> pre-litigation era in the US:  see Aldo Leopold for the value of
> growing up understanding that everything isn't set there for humans
> convienience..
> 
> 
> I respect Rod's insistence on caution in trafficking in non-indigenous
> plants, but I don't think he's in a position to judge the American monarch
> plant projects.
> 
> loren russell, corvallis, oregon
> 
>
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index