Sabre Wasp - Rhyssa persuasoria

Sometimes called the Giant Ichneumon, this is the largest ichneumon in Britain and one of the largest in Europe (10–40 mm). An easy species to identify due to the striking pattern of small white spots along the entire length of the thin, black body (not just the abdomen), red legs, long ovipositor and large size . If you look closely you should also see it has transverse ridges on the top of the thorax, at the front, which it uses to brace itself as it emerges from the wooden burrow it has pupated. Large females are the largest ichneumonids in Britain, though some can be considerably smaller. The ovipositor is longer than the length of the body.

It is normally found in coniferous or mixed woodland

Peaking in July and August

It searches for the larvae of Horntails or Longhorn Beetles which have buried in fallen timber. The female then uses her ovipositor to drill down to the larvae and then lay an egg which hatches and parasitise the host.

Local but fairly frequent and widespread in Britain

Uncommon in Leicestershire and Rutland.