Pitcher plant in France eats bee-killing Asian hornets

10 August 2015 

Bee-killing Asian hornets spreading across Europe now face a natural enemy that lures them to destruction - a carnivorous North American plant, French experts say.

The head of a botanical garden in Nantes, western France, says the pitcher plant Sarracenia devours Asian hornets - but not European hornets. Nor does it eat bees or wasps.

Romaric Perrocheau recently found a Sarracenia stem full of dead hornets.

Asian hornets are a menace to beehives.

Mr Perrocheau, quoted by AFP news agency, said Sarracenia had "invented a very selective trap" for the aggressive Asian hornets.

The hornets are apparently attracted by Sarracenia's nectar and pheromones on the plant's tubular leaves. Once the hornet crawls inside the rim at the top it easily slips and plunges into the pitcher, to be digested by the plant's juices.

The trap appears to be a European adaptation, as Asian hornets do not exist in Sarracenia's native Massachusetts, in the eastern US. The plant can be grown easily in Europe and is not considered a threat to native flora.

Mr Perrocheau and an entomologist aim to study the contents of 200 pitchers, hoping to identify the chemical secret of their attraction for Asian hornets.

Continued ...

Ants and Carnivorous Plants Conspire for Mutualistic Feeding

May 22, 2013 — An insect-eating pitcher plant teams up with ants to prevent mosquito larvae from stealing its nutrients, according to research published May 22 in the open access journal PLOS ONE by Mathias Scharmann and colleagues from the University of Cambridge and the University Brunei Darussalam.

The unusual relationship between insect-eating pitcher plants and ants that live exclusively on them has long puzzled scientists. The Camponotus schmitzi ants live only on one species of Bornean pitcher plants (Nepenthes bicalcarata), where they walk across slippery pitcher traps, swim and dive in the plant's digestive fluids and consume nectar and prey that fall into the trap. Though the benefits to the ants are obvious, it has been harder to tell what exactly the plants gain. However, plants that harbor the insects grow larger than those that do not, suggesting a mutualistic relationship exists between the two.

In this new study, researchers demonstrated a flow of nutrients from ants to their plant hosts, and found that plants colonized by insects received more nitrogen than those that did not host ants. Ants appeared to increase the pitchers' capture efficiency by keeping traps clean, and also protected the plants by actively hunting mosquito larvae that otherwise bred in pitcher fluids and sucked up plant nutrients.

Read on

Killer plant 'eats' great tit at Somerset nursery

A plant has killed and "eaten" a great tit at a garden nursery in Somerset.
Nurseryman Nigel Hewitt-Cooper, from West Pennard, was inspecting his tropical garden when he discovered one of his pitcher plants had trapped the bird.

He said he was "absolutely staggered" to find it had caught the creature.

It is believed to be only the second time such a carnivorous plant has been documented eating a bird anywhere in the world.

"I've got a friend who's studied these particular plants extensively in the wild and he's never found evidence of any of them having caught birds," said Mr Hewitt-Cooper.

"The other documented time was in Germany a few years ago and that was in cultivation, not in the wild.

'Become wedged'
"The larger ones frequently take frogs, lizards and mice, and the biggest ones have been found with rats in them, but to find a bird in one is pretty unusual."

The pitcher plant is a genus of Nepenthes from South East Asia which attracts and traps insects in a pool of liquid which it then digests.

Mr Hewitt-Cooper said he thought the great tit had been attracted to the plant on Saturday by the insects and landed on its leaf.

"I think it must have leant in to pluck out an insect that was floating on the fluid inside, tipped in too far and become wedged and unable to get out."

Mr Hewitt-Cooper has been growing carnivorous plants such as pitcher plants, Venus fly traps and sundews for 30 years, and has won several gold medals at the Chelsea Flower Show.
http://www.bbc.co.uk/news/uk-england-somerset-14416809