Empididae
Encyclopedia
Fly
True flies are insects of the order Diptera . They possess a pair of wings on the mesothorax and a pair of halteres, derived from the hind wings, on the metathorax...
with over 3,000 described species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
occurring worldwide, but the majority are found in the Holarctic
Holarctic
The Holarctic ecozone refers to the habitats found throughout the northern continents of the world as a whole. This region is divided into the Palearctic, consisting of Northern Africa and all of Eurasia, with the exception of Southeast Asia and the Indian subcontinent, and the Nearctic,...
. They are mainly predatory
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
flies like most of their relatives in the Empidoidea
Empidoidea
The Empidoidea are a large monophyletic superfamily of true flies, the sister taxon to the Muscomorpha . These two groups are sometimes united in the unranked taxon Eremoneura...
, and exhibit a wide range of forms but are generally small to medium sized, non-metallic and rather bristly.
Common names for members of this family are dagger flies (referring to the sharp piercing mouthparts of some species) and balloon flies. The term "dance flies" is sometimes used for this family too, but the dance flies proper, formerly included herein, are now considered a separate family Hybotidae
Hybotidae
Hybotidae, the typical dance flies are a family of true flies. They belong to the superfamily Empidoidea and were formerly included in the Empididae as a subfamily....
.
Some Empididae, such as the Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
an species Hilara maura
Hilara maura
Hilara maura is a species of dance fly, in the fly family Empididae....
, have an elaborate courtship
Mating
In biology, mating is the pairing of opposite-sex or hermaphroditic organisms for copulation. In social animals, it also includes the raising of their offspring. Copulation is the union of the sex organs of two sexually reproducing animals for insemination and subsequent internal fertilization...
ritual in which the male wraps a prey item in silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...
and presents it to the female to stimulate copulation. Empidid larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e are also largely predatory (although some are scavenger
Scavenger
Scavenging is both a carnivorous and herbivorous feeding behavior in which individual scavengers search out dead animal and dead plant biomass on which to feed. The eating of carrion from the same species is referred to as cannibalism. Scavengers play an important role in the ecosystem by...
s) and occupy a wide range of habitats, both aquatic
Aquatic animal
An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...
and terrestrial
Terrestrial animal
Terrestrial animals are animals that live predominantly or entirely on land , as compared with aquatic animals, which live predominantly or entirely in the water , or amphibians, which rely on a combination of aquatic and terrestrial habitats...
.
Evolution and systematics
Empididae are well represented in amberAmber
Amber is fossilized tree resin , which has been appreciated for its color and natural beauty since Neolithic times. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents...
deposits and the family certainly seems to have been well established by the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
period at the latest.
Two groups formerly placed here as subfamilies are now generally regarded as separate families in the Empidoidea
Empidoidea
The Empidoidea are a large monophyletic superfamily of true flies, the sister taxon to the Muscomorpha . These two groups are sometimes united in the unranked taxon Eremoneura...
: Atelestidae
Atelestidae
Atelestidae is a family of true flies in the superfamily Empidoidea. These four genera were placed in a separate family in 1983. They were formerly either in Platypezidae or considered incertae cedis. But while they are doubtless the most basal of the living Empidoidea, the monophyly of the family...
and Hybotidae
Hybotidae
Hybotidae, the typical dance flies are a family of true flies. They belong to the superfamily Empidoidea and were formerly included in the Empididae as a subfamily....
. The Brachystomatidae are also sometimes separated as a distinct family, but this seems to be in error. The Microphorinae were long placed in the Empididae as a subfamily, then briefly classified as a distinct family, and are now considered a subfamily of the long-legged flies (Dolichopodidae).
Among the subfamilies currently placed herein, not all are confirmed to be monophyletic groups. Some rearrangements, in particular regarding the delimitation of Empididae versus Dolichopodidae – which together represent the bulk and the most advanced lineages of the Empidoidea – are likely to take place in the future. The Brachystomatinae, Empidinae and Hemerodromiinae however seem to be natural groups of closest relatives in their entirety, and the Clinocerinae apparently are for the largest part.