Hemlock question

[Rambling Rob]

Hello,

After watching insects such as this hoverfly feeding on Hemlock I wonder if insects are resistant to chemicals in Hemlock which are poisonous to humans or if perhaps Hemlock nectar and pollen do not contain the poisons?



Would bees which forage on hemlock (if any do, that is - I didn't see any) - produce toxic honey?

Any ideas? Thanks, Rob

[leifus]

maybe the chemicals are just in the stems of the plant?

[Johnny81]

I read it is in the stem, young shoots and seeds of the plant. I doubt the pollen or nectar would be toxic, if so I think it may have a harder time to reproduce and disperse (unsure if hemlock can reproduce asexually). I can't find that many facts on this. I am sure someone else will enlighten us

[King Edward]

As far as I know, Hemlock only reproduces by seed. I can't think of any reason for the pollen/nectar to be poisonous. A very large number of plants with insect-pollinated flowers are poisonous to some extent but I don't know of any instances where this extends to the pollen/nectar.

[Cotham Marble]

Originally Posted by Rambling Rob

Hello,

After watching insects such as this hoverfly feeding on Hemlock I wonder if insects are resistant to chemicals in Hemlock which are poisonous to humans or if perhaps Hemlock nectar and pollen do not contain the poisons?

Would bees which forage on hemlock (if any do, that is - I didn't see any) - produce toxic honey?

Any ideas? Thanks, Rob

Toxicity is function of biochemistry, thus different species have differring vulnerabilities and this exists to a greater extent across phyla, for example molluscs and arthropods having often very different vulnerabilities to mammals and birds. Plants have developed toxins for a range of purposes and not all animals are the target of any one toxin see: http://pub.jki.bund.de/index.php/JKA...download/85/74

There are examples, though the specifics escape me, of some invertebrate species absorbing plant toxins as a defensive measure. Reports of toxicity transferred from pollen and nectar to honey does seem to have some scientific validity Mad Honey Sex The Poison Review although large quantities may need to be ingested for it to be an issue. For basic commentary on hemlock toxicity: Medscape: Medscape Access

CM

[Rambling Rob]

Thanks all for your thoughts on this subject. There's loads of Hemlock and Hemlock Water Droplet about here at the moment - and I have certainly seen bees foraging on the HWD.

Those are interesting links CM.

All the best, Rob