Plantwatch: Pitcher plant's sweet nectar is laced with toxic nerve agent

"The pitcher plant Nepenthes khasiana oozes an enticing sweet nectar on the rim of its pitchers for visiting insects, particularly ants, to feed on to lure them into the trap. But the nectar is laced with a toxic nerve agent called isoshinanolone, which strikes at the ant's nervous system, leaving it with sluggish movements, weakened muscles, and causing it to groom itself excessively. Eventually the prey falls upside down in spasms, with the nerve agent sometimes killing it outright."

"But apart from isoshinanolone, the nectar also contains three types of sugars that can all absorb water and make the rim of the pitcher especially slippery, so the prey is more likely to slide down into the pitchers. And so the sweet, toxic nectar is both bait and trap for the many ants and other prey that end up being consumed, giving the plant much needed nourishment in the poor soil in which it grows."

Nepenthes khasiana lures insects, especially ants, with sweet nectar on the pitcher rim. The nectar contains isoshinanolone, a toxic nerve agent that disrupts ant nervous systems, causing sluggish movements, weakened muscles, excessive grooming, spasms, and sometimes death. The nectar also contains three water-absorbing sugars that make the rim especially slippery, increasing the chance that prey will slide into the pitcher. Prey fall into digestive fluids at the pitcher base and are consumed, providing essential nutrients to the plant. The combination of chemical incapacitation and mechanical slipperiness makes the nectar both bait and an effective trap in nutrient-poor soils.

Read at www.theguardian.com