Wild Things

The weird and wonderful in the natural world

Sarah Zielinski

Wild Things

Wild Things

Pretty flower uses dead arthropods to lure protectors

honeybee stuck in a sticky columbine

A honeybee is stuck to the flower of a Van Houtte’s columbine. New research shows that the sticky plant lures arthropods to it as bait for bigger protectors.

Sponsor Message

Look in moist forests along the coast of California and you might find Aquilegia eximia, or Van Houtte’s columbine, a pretty, reddish-orange flower. “The columbine is a big beautiful plant that grows in nice little streams; there are always hummingbirds buzzing around and lots of greenery in these little seeps during the dry, golden California summer,” says Eric LoPresti, whostudies the interactions between plants and insects at the University of California, Davis.

LoPresti is interested in A. eximia not because of its beauty, but because of a not-so-beautiful aspect to the plant: It’s covered in carrion. The plant is a “sticky columbine,” and it traps hundreds of tiny arthropods on its stem, leaves, flower and other parts. The plants are also host to a variety of omnivores, scavengers and predators — bugs and other insects that eat the dead arthropods trapped on the plant’s sticky surface.

LoPresti and his colleagues suspected that there was more to the relationship, and that the plants might be getting a big benefit from covering themselves with dead arthropods. The columbines, they hypothesized, might be luring the tiny arthropods to their death — like sirens in classical mythology — to attract bigger critters that keep away or eat the plant’s main herbivorous predator, the Heliothis phloxiphaga caterpillar.

wasp stuck on columbine stemThe researchers began by testing whether the plant could actually lure arthropods to it. They took pieces of the A. eximia, a bit of stem and a leaf, and placed them in a Petri dish covered in a plastic mesh and a sticky substance. Similar dishes were set up with no bits of plant but the same covering as a control. The researchers left the dishes in a meadow near where the columbine grows. Dishes with plant bits trapped about 21 percent more arthropods than the empty ones. The plants do appear to be luring in the arthropods, possibly with a scent or other volatile chemical, LoPresti says.

The team then removed carrion from some columbines and in the weeks afterward, compared them with plants that hadn’t had any arthropods removed. Plants that still had dead arthropods had about 74 percent more predatory insects, and they were much less likely to be damaged by the caterpillars. When there was no carrion, plants were 121 percent more likely to have damaged reproductive structures. The siren song has definite benefits for the plant, the researchers conclude in the November Ecology.

Insect entrapment is a common feature in the plant world. A few species are carnivorous and eat what they kill, but most are not. LoPresti and his colleagues suspect that many of those may be like A. eximia, using their sticky nature as a defense. “I'm not sure whether other plants rely on it as much as [the] columbine,” LoPresti says, “but I suspect many derive some benefit from scavenging predators.”


For a python, every meal is like Thanksgiving

By Sarah Zielinski 9:14am, November 25, 2015
Burmese pythons rarely eat, but when they do, they gorge. Unlike humans, pythons have adaptations that allow them to survive on huge meals.

Five species that show why ‘bird brain’ is a stupid phrase

By Sarah Zielinski 2:00pm, November 23, 2015
Birds can use tools, make art and understand human language. Why do we assume they are stupid?

Vampire bats share blood to make friends

By Sarah Zielinski 8:17am, November 19, 2015
Vampire bats that share blood with nonrelatives have a wider social network to rely on when they’re in need, a new study finds.

Hungry elephants turn trunks into leaf blowers

By Sarah Zielinski 4:30pm, November 16, 2015
Darwin once observed an elephant using its trunk to blow an object closer. Japanese zoo elephants use the behavior to obtain food, a new study reports.
Animals,, Conservation

Tortoises provide a window into the illegal wildlife trade

By Sarah Zielinski 7:00am, November 12, 2015
Tens of thousands of Indian star tortoises are poached every year, a new study finds.

Windy days mean smaller meals for little penguin chicks

By Sarah Zielinski 8:40am, November 9, 2015
Wind speed appears to affect how much food little penguins can bring home for their chicks.
Animals,, Conservation

Big cats hunt livestock when wild prey is scarce

By Sarah Zielinski 12:39pm, November 5, 2015
Lions, tigers and other big cats tend to hunt livestock only after their wild prey has dropped in availability, a new study shows.
Plants,, Ecology

Marsh grass masquerades as a native species

By Sarah Zielinski 9:13am, November 2, 2015
The abundant cordgrass found in South American marshes may actually have invaded the region more than two centuries ago, a new study concludes.

Wildfires are an unexpected threat to California condors

By Sarah Zielinski 6:30am, October 29, 2015
Lead poisoning remains a threat to California condors, but a new review finds that wildfires may also be a danger to the big birds.

As panda baby grows, mom’s milk changes

By Sarah Zielinski 7:00am, October 23, 2015
In the first month after a mama panda gives birth, her milk changes in composition, a new study finds.
Subscribe to RSS - Wild Things