Ten-Lined June Beetle - Polyphylla decemlineata
The stripes along this Beetle's shell are very prominent, but not necessarily distinct as there are a few similar-looking species. It does make for a beautiful find from Canada's west coast (in Squamish). My dear friend found it sheltering inside his car. Presumably it needed a ride to Vancouver and public transit just wouldn't do. While I'm kidding here, insects do on occasion get transported to new locations via road vehicles or overseas shipping. Such activity can introduce species that are normally considered harmless within their native range into an ecosystem that isn't prepared for them! This can result in pest status, or being labelled an invasive specie should their habit become too detrimental. This specie is fortunately not an invasive one here, as it is native to western North America. It instead has status as a pest of orchards, whereby the adults feed on fruit tree leaves while the larvae feed on their roots! Naturally, this can warrant monitoring of crops to prevent extensive damage, especially for the larvae who may inadvertently destroy young trees during their time developing beneath the soil. Today's specimen has pupated and left that life behind in favor of a more herbivorous routine. Despite the weight of her armored shell, this Scarab is quite capable of strong flight.
For a North American comparison between similar Beetles, my friend described this insect's behavior (when he found it) as similar to that of May Beetles (Phyllophaga spp.), which are more common in my neck of the woods. Both genera seem to have a fondness for flying into lights at nighttime. There is somewhat of a resemblance as well, especially with the soft fluff on the Beetle's underside. The Ten-Lined June Beetle is far more glamorous, however. There's a lack of confirmation on this, but it's possible that those bold stripes gave this Beetle its other common name: the Watermelon Beetle. I'd be hard pressed to say that their feeding habits created that name since watermelons grow on vines rather than trees (the harvest would be much more precarious if that were the case). Finally, should you find a Beetle similar in appearance to this one, take note of its antennae. This individual is likely to be a female as her antennae are reduced in size, but it can still fan out (from a club shape) to better catch scents on the breeze. Male Ten-Lined June Beetles have enormous, (curved) paddle-like antennae jutting out from their heads! Genuinely, you can't miss them! Although particularly ornamental in design, they aren't useful as weapons to batter away rival insects. They elaborately fan out to catch the alluring scent of a female Beetle's pheromones, but I wonder how the male's flight stability and direction are affected by the larger antennae.
Pictures were taken on August 5, 2024 in Squamish with an iPhone 12.
