The Big Bug Hunt: Uncommon Insects

This summer, for the first time, thousands of us took a break from actual gardening to report our insect encounters to The Big Bug Hunt, an international citizen science project that is destined to grow into an invaluable early warning system for garden pests. Japanese beetles were the most frequently-reported pest in the US, with slugs triggering the most reports in the UK.

The thousands of garden insect sightings recorded this year provide an exciting look at which pests are causing problems, when and where, but what about the creatures gardeners encountered that were not found in the identification guides for 60 common garden insects? Many curious gardeners sent in photographs and descriptions, and I got to help figure out the identity of some of the mystery insects. Here is my report from season one.

Unusual Pests

I took the work seriously, because one of the first mug shots to arrive was a bagrada bug eating kale in Riverside, California. Also known as the Painted Bug of Africa, swarms of bagradas are becoming an increasing problem on cabbage family crops in the Southwestern US. About the size of a watermelon seed, bagrada bugs have orange markings on their backs. Sweet alyssum can be used as a trap crop, and chickens are reported to have a good appetite for them, but here we have a new pest that deserves close monitoring.

The brown marmorated stink bug was already on our watch list, but until recently it was mostly seen in the eastern mountains. Now it’s in Michigan, too, as well as some spots on the West Coast. As if it were not bad enough for these bugs to insist on coming inside houses for winter, they may be getting comfortable in gardens too. A gardener in West Virginia found brown marmorated stink bug eggs on lemon balm, which is not a good sign.

I had never heard of three-lined potato beetles until a gardener in Massachusetts said that they had eaten his tomatillos back to nubs. What weird insects! The leaf-eating larvae look like little slugs, but they cover themselves with gooey excrement to keep from being eaten by predators. They consume only nightshade (Solanaceae) family plants, and tomatillos are a favorite. Early intervention is crucial to getting good control.

Big Bugs

Large insects get noticed, no matter where they are. “It looked like a cross between a hummingbird and a bee, with a body that curves around,” wrote one gardener, describing a hummingbird moth (shown in the photo at the top of the page). The mydas fly, one of the largest of all flies, was described as “huge and black with orange marks on its sides, pretty in a scary way.” Handsome mydas flies are believed to eat smaller insects, so this was one of the happier sightings.

The strangest creature reported was eating leaves from a lime tree in Florida. Commonly called an orange dog, it camouflages as a bird dropping during its caterpillar phase, and matures into a giant swallowtail butterfly.

Some people asked about insects encountered outside the vegetable garden – an Eastern-eyed click beetle clinging to a tree trunk in the yard, an ash bark beetle that dropped down a woman’s shirt while hiking in the Ohio woods, and colourful yellow-and-black locust borers hatching out of the firewood in Tennessee. I take this as evidence that the Big Bug Hunt is having an additional benefit beyond data collection: it is making people more aware of insects in general, and that is a very good thing.