The London area has witnessed the arrival of numerous species of Hemiptera in recent years and a number of these are members of the shieldbugs and allies, which are typically larger and more easily identifiable than many other true bugs.
Rambur's Pied Shieldbug (Tritomegas sexmaculatus)
One of these, Rambur’s Pied Shieldbug Tritomegas sexmaculatus was first recorded in Britain in 2011, when it was found at Tyland Barn near Maidstone. Further records soon followed from other parts of Kent and the first inside the LNHS recording area came from Dartford in 2012.
The last few years have seen the species spread rapidly west along the Thames corridor and colonise the wider London area, perhaps aided by the very warm summer of 2018. This range expansion seems particularly associated with river systems, with recent records from both the Lea Valley in north London and the Wandle corridor in the south.
Rambur’s Pied Shieldbug is superficially very similar in size and appearance to the closely related Pied Shieldbug T. bicolor, which is widespread across much of southern Britain. However, adults can be distinguished with reference to two key characters which are illustrated below. In addition, all records of Rambur’s Pied Shieldbug have so far been associated with Black Horehound Ballota nigra, a hostplant which is infrequently used by Pied Shieldbug in south east England.
Click here to learn more about the Pied Shieldbug from the British Bugs website
Click here to learn more about the Rambur's Pied Shieldbug from the British Bugs website
Records of Ramburs Pied Shieldbug submitted to iRecord as of December 2020
Striped Shieldbug (Graphosoma italicum)
The very distinctive red and black Striped Shieldbug Graphosoma italicum appeared at two locations in the LNHS recording area during 2020. Adults were found at Fisher’s Green in the Lea Valley and near Banstead Common, Sutton, where they were associated with Hemlock Conium maculatum and Common Hogweed Heraclium sphondylium respectively. A final instar nymph was found at the Banstead site and it seems likely that both locations support breeding populations. It’s unclear how these have become established, but a pathway of introduction in horticultural produce seems most likely.
This species is widespread in the Channel Islands and on the near continent, feeding on a variety of umbellifers, so its appearance in Britain is not unexpected.
Submit your sightings
Although records of the species discussed here are particularly welcome, please do submit all your LNHS shieldbug sightings using iRecord. Please note that records of Graphosoma italicum should be entered under the very closely related Graphosoma lineatum until the iRecord species dictionary is updated.
Click here to enter shieldbug records through the LNHS iRecord activity
Author: Tristan Bantock
Published: 30/12/20
