10/15/2026
As the weather cools and summer’s greenery gives way to the reds, yellows, and browns of autumn, the season for insects is coming to a close. However, until we have our first freeze, there will still be some spectacular specimens to see if you keep your eyes out! Last week, one of the Farmscape Ecology Program’s entomologists was lucky enough to spot this Pigeon Horntail (Tremex columba) laying its eggs deep in the wood of a dead tree. Although this insect resembles a wasp (and, indeed, is a distant wasp relative), it is harmless: its bright “warning” colors are an example of Batesian mimicry, intended to fool predators into mistaking it for a stinging wasp, and the needle-like structure near the end of its abdomen is not a sting but is rather an egg-laying organ that, as shown here, the female horntail uses to drill into dead wood. The larvae of the Pigeon Horntail are specialist feeders on a wood-decomposing fungus called the Mossy Maze Polypore (Cerrena unicolor), and in order to ensure a food source for her offspring, the female horntail carries the fungus around (using special glands in her body) and inoculates it into the wood at the same time as she lays her eggs.
