Bees can fail to recognise toxins in some flowers when foraging for nectar and pollen, a study has claimed.
Pollinators can unwittingly weaken or kill their broods by gathering low levels of toxins from pollen in plants such as lupins, according to research at the University of Greenwich.
Professor Phil Stevenson said: “Many plants produce a wide range of toxins which we know deter or are poisonous to herbivores.
“What has not been examined in depth before is how these toxins may effect the plants’ major pollinators.”
Prof Stevenson, who is also professor of plant chemistry at Kew, said many toxins are present at low levels and do not kill bees outright.
He added: “They can have sub-lethal effects that affect the whole colony if bees collect nectar or pollen from toxin-containing flowers and bring it back to feed the brood.
“Sub-lethal doses of toxins weaken individuals and broods, making them more susceptible to other stresses such as pesticides, parasites and viruses.”