Looking for spring

Starting about the last week of March, and going until mid-November, I could have a blog that was completely dedicated to invertebrate life. There are so many different insects, arthropods, and other invertebrates, of all different shapes and sizes, that I could post a different one each day and still have lots left over for next year, and the year after, and the year after that. The diversity is astounding. It makes you wonder why there aren’t more entomologists out there.

However, come December, it all dries up. Insects being cold-blooded creatures, that require warm ambient temperatures to function, they all but disappear once the cold and snow arrive. Many survive as eggs or pupae. Some will overwinter as adults, though, finding a protected nook where they aren’t exposed to the harsh winter environment. Before humans, this may have been trees or logs, under rocks or in the crannies in cliffs. After humans, at least a few of these bugs choose to spend the winter in our homes. Usually they just shack up in the walls. But sometimes a warm spell outside, or a leaky draft from inside, can warm them up enough that they come stumbling out, groggy, thinking it’s spring.

I was visited by just such a bug yesterday. I found him on a windowpane as Dan and I were discussing a noticeable draft we could feel coming in from the bottom of that window (the top seemed fine, however). Heaven only knows what prompted him to awaken and make his way inside – it was a bone-chilling (for southern Ontario) minus 30 Celsius (-22 F) overnight last night, and the day before wasn’t much better. But here he was, nonetheless. The first insect I have seen since well before Christmas.

He is a Western Conifer Seed Bug, Leptoglossus occidentalis, a member of the leaf-footed bug family Coreidae, so named for the wide flanges on their rear legs. The other name for the family is squash bugs, as many of them target gourds such as squash and pumpkins. In North America there’s some 80 species, most of which are southern in range. As the common name implies, this species is a native of western North America, and has only been this side of the continent for the last couple of decades, recorded in southern Ontario for the first time around 1985, and New York state in 1990. It’s even become established in France. There are a couple other species from the genus Leptoglossus that have been recorded here in Ontario, but the Western Conifer Seed Bug is the most frequently encountered. The species can be told from the others by the white zig-zag across the back. This individual was actually from my parents’ house last winter, but shows the white zig very well.

Like most insects, this guy can fly, but one doesn’t tend to see them flying very often. They prefer to amble from one place to the next. I got him to open his wings by flicking him from a sheet of paper onto the table, and then tried to be quick with my camera. They have these bright orange and black bars across their abdomen, which may be a mechanism used to startle potential predators (by flicking open his wings he exposes these bright colours), or may be tied to aposematic colouration (bright colours that warn predators of distastefulness or toxicity).

The other thing this photo shows is the two-parted wing that creates the distinctive pattern on the back of true bugs. The wings are called hemelytra – elytra being the name of the hard wing covers that most beetles sport, and hemelytra being half that. The upper part of the bug’s wing is hard and protective, while the lower part is membranous and so useful in flight. This characteristic is also what gives the true bugs the order’s name, Hemiptera (Hemi = half, ptera = wing).

Here’s a close-up of the “leaf” on the bug’s leg. I’m not sure what the purpose of the flattened tibia is. Camouflage, breaking up the outline to look more leaf-like? Is it used in mating, fighting with others, perhaps to produce sound? I didn’t see anything about it on any of the websites I checked out. Maybe it doesn’t have a purpose. But then why would it have evolved?

Another thing that characterizes the true bugs is that their mouthparts have become fused into a long tube that they use for sucking. In this photo the bug is on his side trying to flip back over, but it does expose his belly and that long feeding tube. If you look closely you can see it running along his underside from his head all the way down to the second abdominal segment, where it ends in a dark tip. In the case of this species, the long tube is used to pierce into conifer seeds, primarily pine but also spruce and fir. The bug feeds on the seeds as they’re developing, while their insides is still soft and pulpy. It can sometimes be a pest where conifers are commercially cultivated for their seeds (for instance, for growing plant-a-tree seedlings), but don’t affect mature trees even in outbreak numbers and so aren’t a direct problem for the forestry industry. They don’t bite or sting, or eat things in the house, so aren’t really a problem to homeowners, although occasionally they’ll release a pungent odour if disturbed (much like ladybugs will).

I wasn’t sure what to do with the bug once I finished taking photos. I couldn’t put him outside, obviously. I didn’t know where he came from to be able to put him back there, either. So eventually I decided to put him up on the blinds, and let him fend for himself against the three insect-eating critters in the house. Raven will eat bugs on the spot. This has gotten her into trouble already once when she tried to eat a wasp and it stung her, resulting in her face swelling up so much that she looked like she was a bulldog cross. We only discovered that she had found a wasp when I looked down to see her itching at her swollen face. We tried to find wasps before she did, after that. The cats, on the other hand, like to play with the insects but rarely eat them. Oliver was quick to find the leaf-footed bug and was fascinated by it yesterday, but I noticed today it was crawling across my desk, so obviously the bug either got away unharmed, or the cats lost interest.