[361] Volucella zonaria, Hornet Mimic Hoverfly

[361] Volucella zonaria, Hornet Mimic Hoverfly

Vollucella pellucens, Pellucid Fly

Introduction

Vollucella Zonaria, the Hornet Mimic Hoverfly, is our largest commonly occurring Hoverfly, frequently reported by the public as a Hornet. Vollucella pellucens is another large Hoverfly, sometimes called the Pellucid Hoverfly or Pellucid Fly.

Taxonomy

Kingdom – Animals

Phylum – Arthropods

Class – Insects

Order -Diptera (Flies)

Family – Syrphidae (Hoverflies)

Genus – Volucella

Scientific Names – Volucella zonaria, Volucella pellucens

Names

I can’t trace volucella. Zonaria means relating to a belt. Pellucent means transparent.

Volucella zonaria

This is the largest of the UK hoverflies. It is found in most of Europe but only spread to the UK around 1950. It is now widespread across the South of England and spreading northwards slowly.

I won’t describe it in detail as you can see it from my pictures above.

It is often seen by the public as a Hornet but, to be honest it looks nothing like a Hornet. The shape is much fatter, the colouring bears little resemblance, except for having yellow stripes, and the head and eyes are very different. Perhaps in flight it could be superficially similar. But it has probably evolved to mimic other species as a protection against being eaten, because wasps and hornets have a sting that makes them unpleasant to eat.

If you have never seen a Hornet, think of it as a slightly larger version of a [357] Wasp, which is exactly what it is.

Adult Volucella zonaria feed on nectar. They lay their eggs in the nests of wasps and hornets. Larvae live commensally in the nests, pupate over winter in the soil and emerge in spring.

Volucella pellucens

This hoverfly also seems to have evolved to look a bit like a wasp or bee, perhaps a [052] Bumblebee, but again the mimicry is only approximate. It is not really sensible to call this the pellucid fly (which it is sometimes called) because almost all flies have transparent wings.

Its lifecycle is similar to Volucella zonaria. The female is undisturbed as she enters the nest of common wasps to lay her eggs. Larvae scavenge at the bottom of the nest for food remains, dead wasp larvae and pupae and other insects. They leave the nest to pupate underground.

Other Notes

This is the last of our flies but not quite the last insect.

See also

Three other less common species of Volucella are seen in Britain.

• Volucella bombylans mimics a typical Bumblebee. (Bombylans, of course, relates to the Bumblebee.)
• Volucella inanis mimics typical Wasps. (The Latin inanis means empty, vain or worthless.)
• Volucella inflata is somewhat like Volucella pellucens with orange markings.

[258] Pholcus phalangioides, Cellar Spider

[258] Pholcus phalangiodes, Cellar Spider

Introduction

Pholcus phalangioides, the Cellar Spider, is a long-legged spider native to Asia but now commonly seen in houses in Britain. To some people it is a welcome visitor as it is good at catching and eating other spiders and arthropods.

It may also be called the Long-bodied Cellar Spider, Skull Spider, Daddy Long-legs Spider or just Daddy Long-legs.

This is a classic example of the ambiguity of common names. The name Daddy Long-legs (or Longlegs) is variously used around the World. In the UK it normally means Craneflies – see [235] Nephrotoma and [342] Tipula. In general, in can also be used for Harvestmen, Opiliones, an order of eight-legged arachnids that are not classified as Spiders, or any spider in the family Pholcidae. In biology it can refer to Stylidium divaricatum, a triggerplant found in Western Australia.

Taxonomy

Kingdom – Animals

Phylum – Arthropods

Subphylum – Chelicerata (Arachnids and Sea Spiders)

Class – Arachnida (Eight-legged – Spiders, Harvestmen and others)

Order – Araneae (Spiders)

Suborder – Opisthothelae (All spiders except one extant family)

Infraorder – Araneomorphae (Spiders excluding Tarantulas)

Family – Pholcidae

Genus – Pholcus

Scientific Name – Pholcus phalangioides

Name

Most houses today don’t have cellars but this species prefers darkly lit corners. While all the various organisms called Daddy Longlegs are not taxonomically linked, they are similar and they do have long legs!

Pholcus is Latinized from Greek pholkos, bow-legged. The species epithet comes from Phalangioidea, a superfamily of Harvestmen, named from its type genus Phalangium. The Latin phalangium, meaning a type of spider, comes from Ancient Greek phalangion, a diminutive of phalanx, a battle array.

Description

For a spider, the body of Pholcus phalangioides is not particularly large. In homes in Britain these spiders may be less obvious than [131] the Giant House Spider or the False Widow Spiders, Steatoda.

Their legs are much longer and thinner than other spiders that you may find in the UK. Typically, the body is about eight millimetres in length, with a leg span of about 50 mm.

Females are slightly larger than males. I think this next picture was a male spider tentatively approaching a female.

Their webs are small and untidy and they will often leave the web to hunt for prey, particularly other spiders.

They may live close to others of the same species, even merging their webs a little. But in times of need both males and females may resort to cannibalism.

Habitat and use

Pholcus phalangioides is native to subtropical Asia but has spread to most of the World, where it is found almost exclusively in houses – generally in quiet, darkly lit corners.

Other Notes

Here is a Cellar Spider and its prey, photographed in my home.

The unfortunate victim is a Volucella pellucens, a close relative of [361] the Hornet Mimic Hoverfly

See also

Not closely related, but sharing the name Daddy Longlegs are the Harvestmen, Opiliones.

Taxonomically they are more closely related to mites than to spiders and scorpions, but superficially they have the same appearance with eight very long, thin legs. Whereas spiders have two body segments, generally called the cephalothorax and abdomen (but more accurately the prosoma and opisthosoma,) harvestmen appear to have just one. (There are still two segments but they are joined in an oval shape with no apparent ‘waist.’)

• Leiobunum rotundum is common and widespread throughout Britain and may be found in any undergrowth or vegetation.

• Platybunus triangularis (or Paraplatybunus triangularis or Rilaena triangularis) is another common UK species found generally in forests or among ferns.

• Dicranopalpus ramosus, originally found in Morocco, spread into and across Europe from about 1950. By 2000 it has spread as far North as Scotland. It may be found in England resting on garden walls.