Siricidae of Belgium and the Netherlands

The horntails (Hymenoptera – Symphyta - Siricidae) of Belgium and the Netherlands

Fig. 1: Urocerus augur © Rene de croon

Horntails are a rather small family of large, impressive sawflies. They deposit their eggs in trees and are of concern as potential alien invasive species. Eleven species of horntails have been recorded until now. However, some other species can be found due to the importation of wood.

The giant woodwasp Urocerus gigas is the best known species for most people because of its size and distinctive black and yellow coloration.  Nevertheless, there are two similar species whose distribution in Belgium and the Netherlands is not yet fully understood. Urocerus augur (see fig. 1) and its ‘sibling’ Urocerus sah are frequently misidentified as U. gigas. Although they are rare species, they seem to be expanding their range. U. augur is already known for decades, but U. sah is only recently observed in Belgium. It originates from North Africa and Asia, but observations from Canada and France are also reported. We would like to have molecular evidence for the species. These horntails can be expected nearby conifers like spruce and pine.  

Call for collaboration

For this goal we would like to ask all fellow entomologists to send us their Belgian or Dutch records of Siricidae or contact us for identifications if needed. We hope we can rely on your cooperation. Also observations with photos can be entered into the or platform where they will be validated. Collected specimens (dry or stored in alcohol) will be of high value for this research and can be sent  to one of the authors.


Jorgen Ravoet, Vogelzang 53, 1982 Weerde, Belgium, email:

Fons Verheyde, Aartshertoginnestraat 58/01, 8400 Oostende, email:

Ad Mol, Marie Koenenstraat 12, 5242 EA Rosmalen, Netherlands, email: