# Pigeon tremex (Tremex columba) > A large wood-boring horntail whose larvae develop in dead or dying hardwood; adults are non‑stinging and short‑lived. Source: https://insectscanner.com/species/pigeon-tremex/ (updated 2026-10-10) ## Is it dangerous? **Non-toxic.** Adults do not have a venomous sting. Females have a long ovipositor used to lay eggs in wood; it is not a sting but can look alarming. They do not bite or inject venom. If handled roughly a female could cause a minor puncture wound with the ovipositor; treat as a small puncture wound and clean with soap and water. **Pets:** Not toxic to pets. Larvae inside wood are not accessible to pets; adults are unlikely to harm or significantly interest dogs or cats. ## Quick facts - Scientific name: Tremex columba - Also called: Pigeon horntail - Order: Hymenoptera (Wasps, bees and ants) - Family: Siricidae (Horntails or wood wasps) - Size: 20-50 mm body length (not counting ovipositor; females larger) - Colours: Black, Dark brown, Reddish orange - Habitat: Forests, woodland edges, parks and any site with dead or dying hardwood (logs, stumps, branches). - Range: Native to North America: widespread across the eastern United States and southern Canada, with scattered records farther west. - Active: Adults active in warm months (local summer); most activity during daylight. - Lifespan: Adults live only a few days to a couple of weeks; larvae spend months to several years feeding inside wood. - Effect on plants: Wood decomposer - Pest: no ## Overview Tremex columba is a species of horntail (family Siricidae). Adults are wasplike but lack a sting; females have a long ovipositor used to lay eggs into dead or stressed hardwood. Larvae are wood-borers that feed for months or years in the sapwood of weakened, dying or recently cut hardwoods. Adults emerge in the warmer months and are often seen flying around host trees or resting on trunks and logs. ## How to identify it Adults are robust, elongate wasplike insects typically 20-50 mm long (body only; females larger), with a cylindrical abdomen. The body is reddish-brown to black, and the abdomen usually has yellow bands; legs are often yellowish. Antennae are filiform; wings are clear to slightly smoky. Females carry a visible slender ovipositor at the rear (used for egg-laying), which can be mistaken for a sting but is not used for defense. - Large, stout wasplike insect 20-50 mm long with a cylindrical body and clear or smoky wings. - Reddish-brown to black body, usually with yellow bands on the abdomen. - Females have a long, slender ovipositor projecting from the tip of the abdomen (not a sting). - Exit holes in wood are round and about 6-10 mm across; frass may be seen as powdery wood debris. ## Lookalikes - **Giant ichneumon wasp** (Megarhyssa macrurus): Slender with an extremely long, thread-like ovipositor (often longer than the body) and a thin, waisted abdomen; it is a parasitoid often seen on the same trees, laying eggs onto pigeon tremex larvae inside the wood. - **White-horned horntail** (Urocerus albicornis): A conifer-boring horntail that is mostly black with white bands on the antennae and white leg markings; pigeon tremex has yellow bands on the abdomen and uses hardwoods. ## Life cycle - **Egg:** Eggs are laid by the female into cracks or holes in the bark or directly into sapwood using the ovipositor. - **Larva (wood-borer):** Larvae are cream-coloured grubs with tiny legs and a hard spine at the tail end that tunnel through sapwood feeding on the wood and fungal-decayed material; this stage can last many months or years. - **Pupa:** Pupation occurs within the wood in a cell; metamorphosis from grub to adult takes place inside. - **Adult (horntail):** Adults emerge through round exit holes in the wood, mate, and females seek suitable wood to lay eggs; adults live only a short time. ## Diet and predators - Young eat: Larvae feed on the wood and decayed wood material of dead or dying hardwood trees (sapwood), often in association with wood-decay fungi. - Adults eat: Adults feed little; they may visit flowers for nectar or feed on tree sap and do not feed on wood. - Predators of the young: Larvae are preyed on by woodpeckers and parasitized by specialist parasitoid wasps, notably giant ichneumon wasps (Megarhyssa) that drill through wood to reach them. - Predators of adults: Birds, predatory insects and spiders may capture adults; they are also parasitized or preyed upon by parasitoid wasps. ## Effect on plants and gardens Larvae develop in dead, dying or stressed hardwoods and contribute to wood decay. They are not primary killers of healthy trees but can use recently weakened or cut hardwood. ## Where and when to find it Look on standing dead or dying hardwood trees, cut logs, stumps and firewood. Adults may be seen resting on bark or flying near host wood. - Best time: Warm months (local summer); daytime is best for observing adults. Larvae are inside wood year-round. - Tips: Check for round emergence holes and fine wood dust on or under logs. Photograph adults from the side to show body shape and the female's ovipositor for identification. ## Fun facts - Horntails like Tremex columba are not true stinging wasps: the female's ovipositor is a specialized egg-laying organ, not a defensive stinger. - Larvae often develop in wood that has been preconditioned by wood-decay fungi; the insect-fungus association helps larvae digest wood. - Exit holes made when adults emerge are often the most noticeable sign of past infestation in dead or cut timber. ## Frequently asked questions ### Are pigeon tremex dangerous to people? No. They are not venomous and do not sting in the way social wasps do. The female's ovipositor is for laying eggs and not used for injecting venom. ### Do pigeon tremex bite or sting? They do not sting. They are not known to bite people; a female's ovipositor could cause a minor puncture if handled roughly, but this is rare. ### Why is one in my house? Adults are often accidentally attracted to lights or may fly into buildings while searching for mates or suitable wood. If you see one indoors it likely flew in and will not establish there unless there is infested wood inside. ### Will they ruin my furniture or wooden house? They prefer dead, dying or recently cut hardwood. Intact, sound structural timber and finished furniture are generally not attacked. They are more associated with logs, stumps and weakened trees. ### How do I get rid of them? Remove and dispose of infested or recently cut hardwood (burn, chip or bury according to local rules). Store firewood off the ground and dry; replace or treat severely infested timber. For commercial forestry or severe infestations consult a local arborist or pest control professional for targeted treatments. --- More about this species: [iNaturalist](https://www.inaturalist.org/taxa/63275), [Wikipedia](https://en.wikipedia.org/wiki/Tremex_columba). Identify insects and spiders from a photo with the Insect Scanner iPhone app: https://apps.apple.com/app/id1543946563?pt=126685406&ct=web-markdown&mt=8 Identification from photos is never certain: don't handle insects you can't identify, and get medical advice for bites, stings or allergic reactions.