Bugs of one sort or another, Hemiptera and Heteroptera, are plentiful in woodland and shieldbugs are among the most easily seen as well as most endearing. This may be thanks to their variety of colouration and the apparently clumsy way virtually all of them fly and some of them move, especially when dropping out of sight off foliage when disturbed. Some are predators, some are not.
Generally the group is doing well, with arrivals from mainland Europe and an expansion of range by a few, including the Juniper Shieldbug (Cyphostethus tristriatus, 10mm). This species would be up the creek if it had to rely on Juniper (Juniperus communis) for food, since this is in increasingly short supply in lowland England.
But showing an adaptability matched by that of the Box Bug (see Gardens section), the Juniper Shieldbug has taken to using Lawson’s cypress which, unlike the related Leyland Cypress, produces the cones the shieldbug requires.
Stable species in numbers include the Forest Bug (Pentatoma rufipes, 14mm), found principally on Oak (Quercus sp), the Sloe Bug (Dolycoris baccarum, 11mm), which despite its name is not a specialist feeder and can be seen on many different plants, and the Dock Bug (Coreus marginatus, 13mm). The last-named, which breeds mainly on Docks and Sorrel (Rumex spp), is one of the commonest of all the group though it is not a genuine shieldbug. The robust antennae with four segments place it among the Coreidae or Squash Bug family.
Parent Bugs (Elasmucha grisea, 8mm), which use Birch or Alder trees, are some of the most intriguing of the shieldbug family. Uniquely the female sits over her eggs and first-instar nymphs, protecting them from predators and parasites. She often stays with them in the second or even third instars when they are too large to protect as they lie beneath leaves.
One Rhopaloid bug, Rhopalus parumpunctatus, is shown in the Heathland section but Rhopalus subrufus (7mm) is less particular in its requirements. Though commonest on chalk, it may be found in woodland rides and clearings or indeed anywhere with flower-rich grassy banks.
Not all shieldbugs are herbivores and Troilus luridus (10mm) resembles the Blue Shieldbug shown on the Downland invertebrates page in being a fierce predator. It is a fairly common species equally at home in broad-leaved and coniferous woodland, catching principally leaf beetles, although prey as tough as ladybirds can be taken. As the images above indicate, adults, which are seen mostly in August and September, are nothing like so colourful as the nymphs, whose brightness is perhaps the basis of the scientific name.
Common Froghoppers (Philaenus spumarius) are bugs and capable of jumping some distance. Their nymphs are seen less often than the protective frothy ‘spittle’ they reside in on plant stems. They create this by pumping it out from the rear.
The ground bug Aphanus rolandri (8mm) is a scarce, fast-running, sun-loving species active in a good year, notably 2005, from March to October.
Ant Damsel Bugs (Himacerus mirmicoides, 8mm), which get their English name from the way the larva closely resembles an ant, are predators that eat almost anything smaller than themselves. This includes aphids, which helps give these insects a good name among farmers cultivating crops.
Images © Jeremy Early. All rights reserved.