''Callicera spinolae'', also known as the ivy hoverfly or golden hoverfly, is a species of

syrphid fly Hoverflies, also called flower flies or syrphids, make up the insect family Syrphidae. As their common name suggests, they are often seen hovering or nectaring at flowers; the adults of many species feed mainly on nectar and pollen, while the l ...

within the genus '' Callicera'' and family Syrphidae. It was first described by Italian entomologist

Camillo Rondani Camillo Rondani (21 November 1808 – 17 September 1879) was an Italian entomology, entomologist noted for his studies of Diptera. Early life, family and education Camillo Rondani was born in Parma when the city was part of the French Empi ...

in 1844. Like most species within the family Syrphidae, ''C. spinolae'' are mimics of stinging wasps and bees. This

mimicry In evolutionary biology, mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. In the simples ...

has evolved in order to fool predators as the species mimicked are associated with an unpleasant taste and nasty sting. This specific kind of mimicry is also known as

Batesian mimicry Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates, who worked on butt ...

. It has been placed onto the UK Biodiversity Action Plan list of priority species.

Description

''Callicera spinolae'' have bronze coloured bodies, with an abdomen covered in golden hairs. The golden hairs form stripes down the abdomen, which causes ''C. spinolae'' to resemble wasps and bees. They also possess compound eyes and black antennae with white tips. ''Callicera spinolae'' is known to be one of the largest hoverfly species native to the

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...

with a wing length of 10–12 mm.

Lifecycle

During the Autumn between September and October, ''Callicera spinolae'' will feed and breed. ''C. spinolae'' larvae are saproxylic and are dependent on decaying wood for their survival. Eggs are laid inside wet rot holes in trees. Once hatched the larvae feed on microscopic organisms such as bacteria. Larvae will overwinter within the tree and eventually pupate. The larvae of ''C. spinolae'' take up to two years to pupate. After pupation is complete the hoverfly is fully mature and will emerge from the safety of the tree.

Distribution

''Callicera spinolae'' is rare throughout western Europe. The species has been recorded in the following locations: Southern

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

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, Central

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Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

Tajikistan Tajikistan, officially the Republic of Tajikistan, is a landlocked country in Central Asia. Dushanbe is the capital city, capital and most populous city. Tajikistan borders Afghanistan to the Afghanistan–Tajikistan border, south, Uzbekistan to ...

Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...

and

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. It can also be found within the United Kingdom, however is confined to eastern England mainly in

East Anglia East Anglia is an area of the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire, with parts of Essex sometimes also included. The name derives from the Anglo-Saxon kingdom of the East Angles, ...

Habitat

This species can be found within mature or

ancient woodland In the United Kingdom, ancient woodland is that which has existed continuously since 1600 in England, Wales and Northern Ireland (or 1750 in Scotland). The practice of planting woodland was uncommon before those dates, so a wood present in 1600 i ...

s. Habitats require a mixture of mature, dead and dying deciduous trees in order to provide suitable rot holes for ''C. spinolae'' to lay their eggs. It will also lay its eggs in trees that have been pollarded by humans. This is because pollarded trees are more likely to contain rot holes.

Ecology

''Callicera spinolae'' can be used as a

bioindicator A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...

species, which indicates the presence of dead or dying trees within a woodland habitat. They can often be seen in close proximity to flowering English ivy (''

Hedera helix ''Hedera helix'', the common ivy, European ivy, King's Choice ivy, or just ivy, is a species of flowering plant in the family Araliaceae. It is native to most of Europe and parts of western Asia. Ivy is a clinging evergreen vine that grows on t ...

'') off which it feeds. ''H. helix'' is one of the few plant species, which flowers to provides pollen and nectar during the autumn. Rot holes used by ''C. spinolae'' are also used by other animal species, including the closely related hoverfly '' Callicera aurata.'' Birds such as Tawny owls ('' Strix aluco'') and bats, such as the Brown Long-eared Bat ('' Plecotus auritus)'', also utilise rot holes in ancient woodlands. ''Callicera spinolae'' will use rot holes from a wide variety of deciduous tree species including: Field maple (''

Acer campestre ''Acer campestre'', known as the field maple, is a flowering plant species in the family Sapindaceae. It is native plant, native to much of continental Europe, Britain, southwest Asia from Turkey to the Caucasus, and north Africa in the Atlas Mou ...

''), Beech ('' Fagus sylvatic''), Horse chestnut (''

Aesculus hippocastanum ''Aesculus hippocastanum'', the horse chestnut, is a species of flowering plant in the maple, Sapindus, soapberry and lychee family Sapindaceae. It is a large, deciduous, synoecious (hermaphroditic-flowered) tree. It is also called horse-chestnu ...

''), Ash (''

Fraxinus excelsior ''Fraxinus excelsior'', known as the ash, or European ash or common ash to distinguish it from other types of ash, is a flowering plant species in the olive family Oleaceae. It is native throughout mainland Europe east to the Caucasus and Alb ...

'') and Black Poplar (

Populus nigra ''Populus nigra'', the black poplar, is a species of Populus sect. Aigeiros, cottonwood poplar, the type species of section ''Aigeiros'' of the genus ''Populus'', native to Europe, southwest and central Asia, and northwest Africa.Flora Europaea' ...

References

{{Taxonbar, from=Q10743858 Insects described in 1844 Insects of Europe Taxa named by Camillo Rondani Callicerini