Two late winter/early spring invertebrates

This little crab spider was lurking amongst a bunch of ripening ivy berries. When I disturbed it, the spider quickly disappeared amongst the berries. I posted this picture on Twitter a couple of weeks ago and @ivysuckle kindly identified it for me, as a running crab spider in the genus Philodromus

 There's a shield bug nymph crawling over this lunar landscape of apothecia of the lichen Xanthoria parietina. On Twitter, it was kindly identified for me by @AlanM24217579 as a second instar nymph of the forest bug aka red-legged shieldbug Pentatoma rufipes, apparently the only shieldbug species that overwinters in the nymphal stage.

Shield bug

Red-legged shieldbugs Pentatoma rufipes are very numerous hereabouts at the moment, often sunning themselves on oak leaves.

Shieldbugs generally feed on plant sap by piercing leaf veins with their pointed mouthparts, though they will also eat slow-moving animal prey like caterpillars.

This one had taken a liking to feeding on a bird dropping, which is likely to be a good source of minerals. Many insects, including butterflies, will eat animal excrement as a source of calcium that they need for egg laying.

The grey patch just above the middle leg here is the site of the stink gland, which produces a nauseating fluid that deters predators.

The Field Studies Council publishes this excellent fold-out identification chart of shieldbugs. They're an interesting group to study because a) they aren't difficult to identify b) there aren't too many species, and c) they are quite slow-moving, so they are easy to watch and photograph.

There is also an excellent web site called British Bugs devoted to all the hemipterans, including shield bugs, which can be accessed by clicking here.

Shieldbug nymph

We found this red-legged shieldbug Pentatoma rufipes nymph at Alston yesterday. It will go through further moults before it becomes a winged adult.

Here it is flipped over onto its back, when you can see the rostrum - the long, articulated mouthparts that pierce plant tissues like a hypodermic syringe.

Almost as soon as I righted it the shieldbug shuffled over to a leaf vein, pierced it with the tip of its rostrum and began feeding.

For more on shield bugs, click here

Red-legged Shieldbug

This red-legged shieldbug Pentatoma rufipes was sunning itself on a leaf in a field full of ripening wheat in Durham this morning. Wonderfully armoured insects, aren't they?