Sunday, 31 May 2015

A Bug's Life ...

Another world ...



True bugs, collectively known as Hemiptera, are one of the major orders of insects found in the UK, currently comprising nearly 2000 species. The Hemiptera is split into a number of suborders.

The Heteroptera includes what most people know as the characteristic bugs, including shieldbugs, squashbugs, ground bugs, stilt bugs, assassin bugs, damsel bugs, lacebugs, plant bugs and all water bugs. The Auchenorrhyncha contain the leafhoppers, planthoppers, froghoppers, treehoppers and cicadas. We then have the Sternorrhyncha, which includes insects commonly referred to as psyllids (all of which are in the superfamily Psylloidea) together with aphids, phylloxerans, scale insects and whiteflies. A fourth suborder, the Coleorrhyncha, contains the moss bugs or beetle bugs, though these are not represented in the UK.

All have piercing mouthparts with which they can suck the juices from plants or animals - usually plants. Their mouthparts are contained in a beak, known as a rostrum, which is usually held underneath the body when not in use.

The above images depict an adult Dock Bug (Coreus marginatus) and a mating pair of Hairy Shieldbugs (Dolycoris baccarum). Both species are common and widespread in southern Britain.

Thursday, 28 May 2015

Botanical entomology ...

Greater Butterfly Orchid (Platanthera chlorantha)


P. chlorantha is a distinctive orchid of hay meadows, open scrub, grassland and ancient woodlands, especially along rides and in clearings and along woodland edges. It tends to prefer calcium rich soils such as those found on chalk grassland.

P. chlorantha should not to be confused with the Lesser Butterfly Orchid (P. bifolia), which is about the same size and of similar appearance. The safest way of telling the two species apart is by close examination and comparison of the pollinia - the mass of pollen grains in the plant. The pollen sacs of P. chlorantha are 3-4 mm long and converge above while being widely spaced at the base in an inverted ‘V’ shape. Those of P. bifolia are a couple of millimeters long, vertical, parallel and close together, forming a ‘II’ shape. The flowers of P. chlorantha have an attractive vanilla scent, which gets stronger at night to attract moths, their main pollinators.

Monday, 25 May 2015

Mimicry ...

Fly orchid (Ophrys insectifera)



A number of orchid species use mimicry to attract their pollinators. Insect mimics have evolved to give themselves an advantage, as they don't have to compete to be pollinated like generalists but rather only need to attract a particular insect. O. insectifera is one such species, even impersonating the antennae and sheen on the folded wings of its pollinator. Flowering in May to June, it can be found in a number of calcareous grassland environments in the South Downs National Park.

Sunday, 24 May 2015

Elateridae ...

Athous haemorrhoidalis (Fabricius, 1801)


The Elateridae, or Click Beetles as they are commonly known, are a family of beetles currently comprising 73 species in the British Isles. They are identifiable by their elongated appearance with heads somewhat sunken into the thorax, sharp posterior angles on the pronotum and often toothed or pectinate antennae (the segments are longer on one side giving a comb like appearance). They are named for their ability to flip into the air in order to right themselves when upside down - it is this mechanism that produces the familiar ‘click’. Most species are somewhat uniformly brown or black in appearance, some with a metallic sheen and often a fine covering of silver-grey hairs, though some species are more brightly coloured. Sizes range from 3-4mm up to around 20mm.

Occurring in a wide range of habitats, A. haemorrhoidalis is one of the most frequent spring Elaterids in Britain.

Two's company ...

Dingy Skipper (Erynnis tages)



High in the South Downs National Park a pair of Dingy Skippers' mate ...

Despite its unfortunate name, a freshly-emerged Dingy Skipper reveals a subtle pattern of browns and greys that is quite beautiful. This is our most widely-distributed skipper, despite its decline due to changes in farming practice. Colonies can still be found throughout the British Isles, including northern Scotland and Ireland where, although scarce, is found on outcrops of limestone. Its strongholds are in central and southern England where it lives in discrete colonies with little interchange between them.

Like all skippers, E. tages has an extremely fast flight that can be difficult to follow as it flits along, close to the ground. It is a warmth-loving species, and spends long periods basking on bare earth or a stone that has been baked by the sun. In the late afternoon, the butterflies gather to roost on dead flowers or grass heads, where they take on a moth-like pose, with wings wrapped around the flower head.

Thursday, 14 May 2015

In decline ...

Lapwing (Vanellus vanellus)


The spectacular tumbling display of the male bird, along with its elegant crest and characteristic ee-wit call, make the Lapwing one of our most conspicuous waders. Historically their eggs were collected for food, but the problems they face today are much more complex and these familiar plovers are now on the list of our most threatened birds - with changes in farming practices being the main cause of this decline. Targeted conservation work on individual farms in Sussex and elsewhere have brought impressive increases in breeding pairs, but there are not enough of these intensive schemes to make a difference on a landscape and population scale. Success on nature reserves is at best patchy and any recovery of the Lapwing, if it ever happens, looks likely to be slow.

A beautiful bird which provides fond childhood memories ...

References:

Barfield, C., 2014. Lapwing. The Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on behalf of the Sussex Ornithological Society, pp. 243-245.
Pepper, R.T., 1996. Lapwing. Birds of Sussex. Sussex Ornithological Society, pp. 244-246.

Friday, 8 May 2015

Fritillaries for the Future

A conservation project has been launched to stop the severe decline in numbers of two of the rarest woodland butterflies in Sussex - the Pearl-bordered and Small Pearl-bordered Fritillary.


Butterfly Conservation has set up the three-year project Fritillaries for the Future with funding from the Heritage Lottery Fund, after experts recorded a continual drop in the number of sightings coming in across the county. Both species were once common and widespread in Sussex, but last year no Small Pearl-bordered Fritillaries were seen at the only remaining site in the county, raising fears it may have been lost from the southeast entirely. New data from the UK Butterfly Monitoring Scheme (UKBMS) has also confirmed that the Pearl-bordered Fritillary has undergone a 72% decline in numbers across the whole country since 1976.

Sunday, 3 May 2015

Shades of purple ...

Purple Sandpiper (Calidris maritima)


Few waders are as closely restricted to a particular habitat as C. maritima, which is fundamentally a bird of the very edge of the surf, where it searches through wave-washed, seaweed-covered rocks for invertebrates.

It breeds on the Arctic islands of Canada, Greenland, Iceland, Svalbard, northwest Scandinavia and Russia. In Europe, the British Isles are on the extreme southwestern edge of its range, with up to four pairs breeding in Scotland since the late 1970s. It winters regularly at a small number of sites in Sussex, where it is a scarce winter visitor and passage migrant, with only Newhaven Harbour consistently holding a wintering flock during the last 50 years, where they are found on the harbour arms.

References:

Paul, N. (2014). Purple Sandpiper. The Birds of Sussex. Thetford: British Trust for Ornithology (BTO) Books on behalf of the Sussex Ornithological Society, pp. 258-259.
Curson, J. (1996). Purple Sandpiper. Birds of Sussex. Sussex Ornithological Society, pp. 256-258.