White-margined Burrowing Bug
I love getting questions about the wild side of PEI and so was thrilled to get this photo from Megan Jones. She found this clump of bright red insects in some old straw near her barn and was curious about their identification and whether they could be invasive. These are the lovely – and native – nymphs of the White-margined Burrowing Bug (Sehirus cinctus). Let’s take a look!
You could be forgiven for thinking these are Lady Beetles at first glance, given their similar red-and-black colouring. But White-margined Burrowing Bugs are unrelated to Lady Beetles and are the only members of their family (Cydnidae) found on the Island.
These insects are well-named: adults are shiny black, with a white line that circles the side of the thorax and abdomen like a pinstriped margin. Adults overwinter by burrowing into the ground or under leaf litter and emerge early in the spring to find mates. Each female lays up to 150 eggs in the soil, and – unlike many other insects – not only guards these eggs until they hatch but also tends and feeds the young nymphs for several days, until the hatchlings can feed themselves.
Over the summer, the nymphs develop through five stages (called instars), getting larger each time until they eventually transition from their wingless, red-and-black form to winged black-and-white adults, each just six millimetres (1/4 inch) long. It’s not unusual to see groups of nymphs this time of year, as they prepare for their final transition and overwintering, and you might spot groups of adults when they emerge in spring.
White-margined Burrowing Bugs are native, common, and nothing to be concerned about. They feed mostly on plants in the Mint and Nettle Families and are not pests of gardens or agricultural crops. Like many insects, they can become numerous when conditions are right, but they don’t bite or sting and so are little more than an annoyance during boom years.
If you have a question about PEI’s wild side, it’s likely others do too! So, follow me here or on Facebook and Instagram, join the conversation, and Ask a Naturalist about PEI untamed!
