Beetles caught 'mating with beer bottles'

SEX-starved jewel beetles - usually seen hanging like baubles off native Christmas trees - have been caught trying to mate with beer bottles.

Researchers believe the 20mm insects are mistaking sun-glistened bumps on the bottom of discarded bottles with the female of the species.

Jewel beetles are abundant in WA and are important for pollinating native plants - including the WA Christmas tree (Nuytsia floribunda), which is only found in the South-West.

The insects are most active during the hot summer months, after sometimes spending years living under the bark of trees.

But now the females are being left high and dry as males chase bottle over booty.