Bee-hunting beetles are the first animals known to fake the smell of flowers

Amazing stuff!

"The life of a bee isn’t all nectar and pollen. Bees have to watch out for trickery, because some plants entice them without offering any reward. Certain orchid flowers, for example, look and smell like female bees, prompting males to pollinate them when they try to mate. “Deception is everywhere,” says May Berenbaum, an entomologist at the University of Illinois Urbana–Champaign.

A newly discovered form of deception is more convoluted yet: The larvae of blister beetles emit a mix of volatile scents that resemble a flower, attracting bees. The beetles then latch onto the bee, hitch a ride to its nest, and eat the eggs. This luring strategy, described last week in a preprint on bioRxiv, is the first known example of an animal mimicking the smell of a flower.  ..."

From the abstract:

"Animals are not known to biosynthesize floral signals to manipulate pollinators, although such mimicry could profoundly shape plant-pollinator interactions. Larvae of the poisonous European blister beetle Meloe proscarabaeus parasitize multiple solitary bee species, yet the mechanism enabling host attraction has remained unresolved.

Here we show that these larvae lure bees by emitting a bouquet of volatile compounds that closely resembles floral scent.

Chemical analyses reveal a complex blend of monoterpenoids derived from (S)-linalool, a ubiquitous floral volatile.

Behavioral assays demonstrate that these compounds function as floral cues, eliciting attraction in bees.

Transcriptomic and functional analyses identify cytochrome P450 enzymes that oxidize (S)-linalool, demonstrating that larvae biosynthesize these plant-like volatiles de novo.

Together, these findings broaden the scope of interkingdom chemical mimicry and uncover a striking form of sensory deception in which an insect chemically assumes the signal identity of a flower, revealing that animals can evolve biosynthetic pathways to exploit plant–pollinator communication."

Bee-hunting beetles are the first animals known to fake the smell of flowers | Science | AAAS

The floral illusion: A parasitic beetle mimics the scent of flowers to attract bees (open access)

Fig. 1 Lifecycle and volatile emissions of Meloe proscarabaeus triungula.