The burnished bronze bug

This is not the common name of this large shield bug, Pentatoma rufipes, which actually goes by Forest or Red-legged Shieldbug, but it should be. I found the individual above todaty on a pavement today and had a plastic pot at hand to bring it home and give it the white bowl treatment to bring out its colours. This shiny, metallic beauty becomes an adult at the end of June or July, as the photo below of a teneral adult, just moulted out of its also shiny last instar nymph skin shows. Even when the full colours are not evident, the prominent 'shoulders' are characteristic.

Teneral Forest Bug

Large shieldbugs are relatively easy to identify, even at their nymphal stages. The British Bugs site is always good starting point.

A close look at an Alder spittlebug

This cold Alder Spittlebug, Aphrophora alni, sat on a rose leaf, cold and reluctant to fly, so I decided to give it a session on the white bowl, and it graciously obliged. The Alder Spittlebug is one of the largest British froghoppers (9-10 mm), so called for their - alleged - resemblance to a frog and their ability to jump. Unlike the Common Froghopper, which is smaller and on close inspection covered on fine hairs, the Alder Spittlebug has fine dark punctures and is less variable in colour. They also have a distinctive keel in the middle of the thorax, visible in the photo below. They are sap feeding insects, both nymphs and adults, and they feed on a range of plants. Adults are usually found in trees, but they descend to lower vegetation to lay eggs. 
 Froghoppers are the fastest jumping insects, outperforming fleas: they can jump up to 70 cm in the air, with an acceleration equivalent to 550 times gravity. Their hind legs - tucked underneath their wings in the photos - are powered by huge muscles in the thorax and the catapult-like jump is effected by elastic energy stored in a membrane. Another fascinating aspect of their behaviour is sound communication. Froghoppers and other small homoptera have a repertoire of vibrational drumming sounds - inaudible for us - which transmit through the substrate where they sit and that individuals use in communication. Songs can be territorial, regulating the distance between feeding individuals, or involved in attracting a mate, emitted by males and to which females respond, and they also sing as a form of fighting when two males are close together or when in distress.

More information
Burrows M (2009). Jumping performance of planthoppers (Hemiptera, Issidae). The Journal of experimental biology, 212 (17), 2844-55 PMID: 19684220 Tishechkin (2003). 

Tishechkin, D.Y. (2003). Vibrational communication in Cercopoidea and Fulgoroidea (Homoptera: Cicadina) with notes on classification of higher taxa Russian Entomology, 12, 129-181

Chameleon bug

I took this portrait of a Green Shieldbug during a light shower today. There are three Green Shieldbugs feeding on the spurge, one of them, is the brightest green:

Compare with one I found at the end of March:

A brown, pinkish-purple individual. It is hard to believe they are the same species, but this colour change, which can happens in a few days, is typical of Green Shieldbugs. There is a single generation per year, with green adults emerging at the end of the summer. In November, the Green Shieldbug turns a dark bronze brown, which merges it better with its surroundings during overwintering. Come spring, adults emerge from their overwintering sites and climb over trees and bushes to feed, mate and lay eggs, and they go back to green again. A true chameleon bug!

Pond Skater

One of my earliest bug memories is watching pond skaters moving effortlessly and magically over the water. Pond Skaters, Gerris sp., also known as Water Striders, are true bugs: they piercing mouthparts are used to suck the juices of the insects they predate. Their legs are clothed with water-repellent hairs and they propel themselves with their middle legs in a flicking glide. Their front legs are small and kept tucked ahead of them, sensing the vibrations in the water from other ponds skaters or potential prey that have fallen in the water, and also grasping and holding their prey. They are seven similar species of Pond Skaters in the U.K., and they are sometimes found in the same pond. Pond skaters are active in these mild days of autumn and will overwinter as adults, moving away from the water with the first frosts. Many pond skaters species are polymorphic and have long-winged and short-winged morphs. In species with two generations per year, the long-winged form tends to be the overwintering generation - which is also the dispersive one - while the summer generation tends to be short winged. When the winter comes, short-winged individuals, unable to fly, will crawl out of the water and hide in the bank, while long-winged ones can fly away from water, to sites that are free from risks of flooding or freezing. In the spring, emerging pond skaters will fly back to ponds and lakes, using the reflections of the water - or other shiny surfaces - as guide.
Pond skaters, as other true bugs, go through five instars before becoming adults. The individual of the top photo is a nymph (24 Jun 2011), the one at the bottom, an adult (2 Jul 2011). Although the photos are from earlier in the year, smaller nymphs were still in a local pond last monday.

On the Western Conifer Seed Bug and Christmas trees

This large, striking bug entered the house at night through an opened window. It is the alien species Leptoglossus occidentalis, the Western Conifer Seed Bug, a native from western North America, where is a minor pest of conifers. This species has long antennae and large rear legs, a pale zig-zag mark on the wings, and distinctly flattened and enlarged tibia, which gives the name to its group, the leaf-footed bugs. During last century, this species spread across North America and during the last decade has also been introduced in Europe, where it has quickly spread from the initial introduction point in Italy. It was accidentally transported in timber, and its spread could also possibly been aided by Christmas tree shipments. Nymphs and adults feed on the sap of cone seeds and buds, and therefore the damage is restricted to seed production. In continental Europe, where there are established populations, it does not appear to cause much damage. Every now and then, there are migratory influxes to the U.K. from the continent, as occurred in 2008. The bug often falls in moth traps, and is a good flyer. It is most obvious in the autumn, when it moves about looking for suitable hibernation sites, often entering buildings and sometimes forming large aggregations, attracted by pheromones produced by males. Nymphs have been found in a few sites in the U.K., so it appears to be establishing.
 If you have seen this bug, you can report it here.

References
Lis, Jerzy A., Barbara Lis & Jerzy Gubernator (2008). Will the invasive western conifer seed bug Leptoglossus occidentalis Heidemann (Hemiptera: Heteroptera: Coreidae) seize all of Europe? Zootaxa, 1740, 68-68
Taylor, S.J., G. Tescari & M. Villa (2001). A nearctic pest of Pinaceae accidentally introduced into Europe: Leptoglossus occidentalis (Heteroptera: Coreidae) in Northern Italy. Entomological News, 112, 101-103.
Blatt, S. & Borden, J. (1996). Evidence for a male-produced aggregation pheromone in the Western Conifer Seed Bug, Leptoglossus occidentalis Heidemann (Hemiptera: Coreidae) The Canadian Entomologist, 128 (4), 777-778 DOI: 10.4039/Ent128777-4

A Hawthorn Shieldbug

We came across a couple of Hawthorn Shieldbugs, Acanthosoma haemorrhoidale, on a large hawthorn hedge at the edge of our local park yesterday. This is a strong contender for the most beautiful British shieldbug, large and shiny, with bright green and red markings, finely punctured and with broad, pointy "shoulders". They are found in a range of trees and shrubs, but their favourite food is haws, the berry produced by the Hawthorn, although they also feed on leaves or other fruit such as apples, piercing them with their rostrum, their sucking, needle-like mouthpart. As other shieldbugs, they overwinter as adults, often darkening their colours at the end of autumn, and emerge in the spring to feed and mate. Eggs are laid around May and the nymphs develop during the summer into increasingly larger stages quite different in colour to the adults. The new adult generation would emerge in August.
 Until recently, the Hawhorn shieldbug was common only in southern england, but his distribution has expanded north recently and now can be found in Scotland too.

A Hawthorn Shieldbug on Hawthorn

Final stage Nymph (2nd August 2008)

A forest bug

I realised a few days ago that I have not posted much about bugs (Hemiptera) in BugBlog. To start making amends, here comes a short one on a common bug these days, the forest bug Pentatoma rufipes, a quite large, showy shield bug easily to recognise for its spiky lateral thorax projections and orange legs. There are quite a few bug species about, many still nymphs, but an adult forest bug landed on my shoulder yesterday. Forest bugs lay their eggs on bark of oaks and other trees around this time of year and the nymphs hibernate on the trees. The adults are partly predatory. For lots of information and beautiful photos of British bugs here.

Cuckoo spit and froghoppers

The lavender bushes are still far from bloom, but they are covered on the decorative white froth blobs produced by the common froghopper or meadow spittlebug, Philaenus spumarius. The spittle-like foam (widely known as cuckoo spit in the UK) hides green nymphs which suck on the plant sap safe from predators and dessication.
 I uncovered the soft-bodied, green nymphs this morning by gently spraying the spit with water. Three were hiding in a quite large spit, head down, nestled in the joint between leafs and stalks, so that they resemble plant buds. In the afternoon they were covered again in the spit. To make the spit they mix air with their watery deyections and a surfactant secreted by abdominal glands using their legs, and they rest head-down, the spit rapidly covers them.

The adult - said to rememble a frog - is found from June all through the summer and until the first frosts.  It has powerful rear legs and is able to jump long distances - hence the 'froghopper' name and it is is found in the same places as the larva. The following photos, from July 2007 illustrate the large colour variation of the adults, with have similar feeding habits as their sessile nymphs, but with a very different, much more active lifestyle.

A review of Philaenus spumarius life history indicated that there is no less than 16 colour forms, and a lot of research has been devoted to the genetic basis of this colour polymorphism.

More information:
Yurtsever, Selcuk (2000). On the Polymorphic Meadow Spittlebug, Philaenus spumarius (L.) (Homoptera: Cercopidae). Turkish Journal of Zoology, 24 (24), 447-459. here.