Acanthosomatidae

Keeled Shieldbugs

HEMIPTERA > HETEROPTERA > PENTATOMORPHA > PENTATOMOIDEA > Acanthosomatidae

The Pentatomoidea superfamily groups together five families of 'shieldbug', so named due to their general shape, but also because of their large scutellum that covers much or all of their wings. In some countries, such as the USA, they're called 'stinkbugs' as many species emit a pungent fluid when threatened. Apart from being characterised by the well- developed scutellum, these species have ocelli, five-segmented antennae and two or three-segmented tarsi.

The Acanthosomatidae family is represented in Britain by five species, although only four are normally considered as the Bilberry Shieldbug hasn't been seen for many years and is almost certainly extinct. They can be distinguished from the Pentatomidae 'typical shieldbugs' by having two-segmented tarsi.

Whilst all four are regarded as being common and widespread across much of the country, the Juniper Shieldbug [Cyphostethus tristriatus] is a more localised species within areas where Juniper is growing. It used to be pretty much confined to southern woodlands, but its range is now extending due to the planting of both Juniper and Cypress in parklands and gardens. It's an attractive species that I'd obviously like to see, although that may be quite difficult based on the current NBN Atlas records as there have only been a handful of confirmed sightings from Dorset over the past few years!

Fortunately, the superficially similar green species, Hawthorn Shieldbug [Acanthosoma haemorrhoidale] and Birch Shieldbug [Elasmostethus intersinctus] are apparently a bit easier to find in my general area, although it took me a while to find the latter. The common names obviously relate to their main food plants but, even though the Hawthorn Shieldbug is indeed primarily associated with Hawthorn, it can also be seen on many other varieties of shrubs and trees; similarly with the Birch Shieldbug, which isn't confined to Birch as it can often be found on Aspen or Hazel.

The final species is the Parent Shieldbug [Elasmucha grisea], so named due to the female's habit of guarding her eggs until they hatch. This species lacks the green background colour of the others, being more of a reddish or grey/brown colour with some darker markings. It is most likely to be found on Alder or Birches.

Footnote: shieldbugs in general are a popular group of species that are usually referred to by their common names.

Updated, Feb.25 (v.3)