Rare bug spotted in St. Albert
Green tortoise beetle eats Canada thistle
Saturday, May 31, 2014 06:00 am
Local bug-lovers are in a tizzy this week after a local photographer spotted a rare thistle-eating beetle in St. Albert.
Alberta entomologists recently confirmed that a green tortoise beetle had been spotted in St. Albert. The little green bug is a rare sight in this province, with few if any locally collected examples known in museum collections.
Local photographer Al Popil says he spotted the bug on the hood of his car on May 19 while testing out a new macro lens.
“Total fluke,” he says of the discovery.
“If he wasn’t on a white car, I probably wouldn’t have seen him.”
Popil says he took the bug into his house for some photos, after which it flew off. He found the dead bug in his laundry room about a week later.
Popil says he sent his photos to Edmonton entomologist and spider expert Robin Leech for identification.
“A couple of days later, he says, ‘Oh, you’ve got something special there.’”
Leech says he and other entomologists recognized the bug as a cassida rubiginosa, or green tortoise beetle. It’s an introduced species that was brought to North America to feed on Canada thistle – a noxious weed.
“It’s neat because it has a roundish shape, and the rim is much like that of a cup or bowl,” he says.
When threatened by ants, the tortoise beetle uses its sucker-like feet to clamp down flush with a leaf so that its shell protects its limbs and head.
Leech says he was surprised to see Popil’s photo, as he had never seen a member of this beetle species in Alberta before. (They are very common in Africa.)
This beetle has shown up in Alberta before, notes entomologist John “the Nature Nut” Acorn, but is not at all common – the University of Alberta has no Alberta examples in its collection. Another one was spotted at the Devonian Botanic Garden in the week of May 19, with a third collected in a west Edmonton trap last week.
“It’s like a green ladybug.”
Leech says this sighting could mean that this beetle is moving further north into Alberta. It also might have been here for years without anyone noticing it.
Popil says he plans to donate the bug to the U of A.