Firebug - Pyrrhocoris apterus
Valentine's Day may have been last week, but there's still one more mating pair of insects that I'd like to highlight while romance is still fresh in our minds. Their red color would have certainly been a good fit for the aforementioned holiday, but then it would be too easy. In any case, I've typically found this common specie of Red Bug in one of two scenarios: either as an individual insect running across the wilderness, like some of the images shown here; or as a member of an aggregation featuring dozens or hundreds of crimson-colored Bugs. For the latter, all nymph stages of this insect's life cycle can be observed alongside the adult forms as they aggregate along a tree, plant or secure man-made structure. While a part of an aggregation, these insects share a living area and food source and will stay close together to maintain warmth and protection from insectivorous threats (i.e. too many insects to track one or one insect may be eaten over another). However, while looking closer at several prior recorded and photographed Bug hordes, I noticed that there were no mating pairs of these Bugs to be found. Thusly, we come to the pair found among grass and wood chips. It seems that rather than mate as a part of the aggregation, the adult Bugs will strike out on their own to find mates, but is that the whole story?
Naturally, there might be a few individuals within such an aggregation who would form mating pairs as the purpose of these pheromone-signaled aggregations is to bring Bugs together for mutual benefit. Among these large insect groups, bringing them together can be a simple and effective way to find a mate if they are willing to wait for a few molts. Many individuals within Firebug aggregations (particularly the ones that I've seen) are nymphs, and thusly lack the appendages needed to mate. Moreover, while there are many insects and pheromones within an aggregation, perhaps there are too many? One of the crucial parts of an insect's life is to pass on its genes, but with so many males and females to choose from, who's to say that the efforts of one male won't be supplanted by another? As such, it may be in the best interest of the male Firebug's genes to bring a female away from the aggregation. Thusly the male Firebug practices mate guarding and remains attached to the female for hours to days of mating!
However, Common Firebug females are usually only receptive after feeding (eggs and mothers need nutrients) and they actually benefit from having multiple partners so that many of their eggs become fertilized. So perhaps a female Firebug benefits more from the aggregation? It sounds like it, but consider one particular long term decision: there is competition for nearby nesting sites, and amassing all the Firebug eggs in on area can prove disastrous should they be destroyed. Moving away from the aggregation may be beneficial in terms of dispersal and discovery of better sites. This is particularly crucial since this insect typically has reduced wings (but sometimes doesn't), and relies on running and scent detection to find new areas for food and egg placement. Although different in their approaches and needs, male and female Firebug adults at least want the same thing at the end of the day, and their cooperation together ensures a successful batch of new Firebugs will emerge after overwintering. Finally, even if laid far apart, it's never a lonely life as a hatched Firebug nymph; soon the pheromones are detected and the aggregations of these deep-red insect starts again!
The solo Firebug pictures were taken on March 22 and May 6, 2021 and the mating pair pictures were taken on May 13, 2021; both with a Google Pixel 4.
