For males, the latter ¾ of the abdomen is usually an orange to yellow. Common hosts include various pine and Douglas-fir. Sirex longicauda. Sirex longicauda also resembles the European wood wasp in general body shape and color. A key difference is that Sirex longicauda has a very long ovipositor in contrast to the European woodwasp’s relatively short ovipositor.
If any Sirex species is detected it should be immediately forwarded to Colorado State University extension, through a local office. Determination will be made there whether it is a native Sirex species or Sirex noctilio, the European woodwasp.