Pigeon Horntail – Tremex columba
Symphyta – Sawflies, Horntails, and Wood Wasps / Family Siricidae (Horntails)
Live adult pigeon horntail photographed at the Morton Arboretum, Lisle, Illinois, USA.
The Family Siricidae was until recently believed to be the sole living representative of the superfamily Siricoidea, a group well-represented in early Tertiary and Mesozoic times. Horntails are non-social wasps, unusual in that the larvae pupate inside dead wood, much like wood-boring beetle larvae. These larvae are often targets of wasps in the Family Ichneumonidae, which in turn drill into the wood to lay their eggs on them.
You can see one such wasp (Megarhyssa) drilling and laying eggs HERE.
The last tergite of the abdomen has a strong, projecting spike, thus giving the group its common name. The ovipositor is typically longer and also projects posteriorly, but it is not the source of the name. (Both are readily visible in the photograph below). A typical adult horntail is brown, blue or black with yellow parts in color, and may often reach up to 4 cm long. [2]
That’s how fast this gal disappeared. I have only ever seen one of these and I was not ready. I was disappointed because this thing was huge, about 40mm! Visible is the eponymous spike-like projection on the rear of the abdomen, above the ovipositor.
References
- Bugguide.net, “Pigeon Horntail”
- Wikipedia, “Horntail”
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