Streaked bombardier beetle

The Streaked Bombardier Beetle is one of only two species of bombardier beetle found in the UK. The other looks very similar and is called the Common Bombardier (Brachinus crepitans) – although it too is very rare.

The Streaked Bombardier has an astonishing party trick, and there’s a clue in its name. If threatened, it can take accurate aim with its flexible abdomen and let fly with a ‘bomb’ of noxious, boiling chemicals (hydroquinones and hydrogen peroxide), delivered with an audible, explosive ‘pfut’!

This works well as a deterrent to other insects, much larger predators and nosey humans alike.

The Common and Streaked Bombardier Beetles have a metallic blue-green wing case (elytra) with a narrow orange-red head and back (thorax), however the Streaked Bombardier has a distinctive red dash along its back and measures up to 7.5mm long.

Not much is known about the ecology of Streaked Bombardier Beetles, although we think that the larvae feed on Amara and Harpalus ground beetles. They favour the East Thames area because of its estuarine character and the relatively warm, dry conditions there, because in Britain the beetles are at the northern limit of their natural range.

Like so many species in the Thames area, they depend on the thin soils, rubble and bare ground found in its brownfield sites. Protecting and managing brownfield sites in the Thames area is incredibly important if we want to be sure we can keep this wonderful beetle as part of UK wildlife.

The recent history (or what we know of it) for the Streaked Bombardier makes it clear what a precarious existence it has here in the UK:

• In 2006, a colony was discovered in a brownfield site near the Thames Barrier that was waiting to be developed.
• This prompted the 2007 translocation of the colony to a specially prepared site nearby, consisting of rubble, crushed brick and concrete. 61 beetles were moved. The development has now destroyed the original site of the colony.
• In 2010, a single female was found a few miles away at Mile End Park in routine monitoring. This suggests that other populations of the Streaked Bombardier beetles may be found in the large brownfield areas found in East London.
• In 2011, a new colony was found on a single mound on a large brownfield site, which has now been developed, in Silvertown.
• In 2012, Buglife staff discovered a new population in Newham, close to London City Airport, again on a single mound due to make way for Olympics infrastructure. Buglife worked with the developers to re-design the project’s layout, which meant the beetles could stay safely where they were. This mound is now the only known intact colony of the species in the UK.

Buglife continues to monitor the status of the Streaked Bombardier research and conserve new colonies.