Adults are found on tree trunks and foliage and are attracted to flowers, decaying fruit, excrement, sweat, and decomposing snails. Larvae are found on fresh and decaying vegetation, carrion, human corpses, and root nodules. Most larvae are either phytophagous (eating plant material) or saprophagous (eating decomposing organic matter). Some are predatory on other insects and others have been found in human lesions, while others are of minor agricultural significance.
For terms see Morphology of Diptera
Signal flies are very variable in external appearance, ranging from small (2.5 mm), slender species to large (20 mm), robust individuals, often with body colours having a distinctive metallic lustre and with face and wings usually patterned with dark spots or bands. The head is large. Frontal bristles on head are absent. Two orbital bristles are on the head. The frontal stripe is pubescent and the arista is more or less long and pubescent. The antenna1 grooves are deep and divided by a median keel. Radial vein 4+5 bears bristles. The costa is without interruptions and the anal cell is elongated, bordered on outer side by an arcuate or straight vein. The abdomen of male has five visible segments and the female has six.
Many bizarre forms of morphology and behaviour occur in this family. Heads and legs (fore legs especially) may be oddly shaped, extended in various ways or with adornments, all of which serve to supplement agonistic behaviour. Such behaviour underlies social and sexual interaction between individuals of the same species of signal flies, first researched in Australian species of the genera Euprosopia image and Pogonortalis
In males of Pogonortalis, the length and degree of development of hairs (setae) on the lower facial area, together with widening of the head, facilitates territorial dominance by head-butting and rearing-up behaviours. Head-butting is taken to the extreme in the Australasian genus Achias, in which species have the fronto-orbital plates expanded laterally to produce eyestalks.
Some species have prominent eyestalks also found in the family Diopsidae. In the Diopsidae, eyestalks develop through lateral development of the frontal plate, with the result that the antennae are situated on the stalk near the compound eye. The process of development in signal flies is different in that the fronto-orbital plates expanded laterally to produce eyestalks and consequently the antennae remain in a central position. This is an example of convergent evolution. The development of eyestalks reaches its extreme in the platystomatid species Achias rothschildi Austen, 1910 from New Guinea, pictured here in which males have an eye-span up to 55 mm.
See also 
Adults are sometimes amongst the most morphologically bizarre forms of all the Diptera.
Data related to Platystomatidae at Wikispecies
The Acalyptratae or Acalyptrata are a subsection of the Schizophora, which are a section of the order Diptera, the "true flies". In various contexts the Acalyptratae also are referred to informally as the acalyptrate muscoids, or acalyptrates, as opposed to the Calyptratae. All forms of the name refer to the lack of calypters in the members of this subsection of flies. An alternative name, Acalypterae is current, though in minority usage. It was first used by Justin Pierre Marie Macquart in 1835 for a section of his tribe Muscides; he used it to refer to all acalyptrates plus scathophagids and phorids, but excluding Conopidae.
The confusing forms of the names stem from their first usage; Acalyptratae and Acalyptrata actually are adjectival forms in New Latin. They were coined in the mid 19th century in contexts such as "Muscae Calyptratae and Acalyptratae" and "Diptera Acalyptrata", and the forms stuck.The Acalyptratae are a large assemblage, exhibiting very diverse habits, with one notable and perhaps surprising exception: no known acalyptrates are obligate blood-feeders (hematophagous), though blood feeding at various stages of the life history is common throughout other Dipteran sections.Amphicnephes
Amphicnephes is a genus of signal flies in the family Platystomatidae. There are at least three described species in Amphicnephes.Amphicnephes pullus
Amphicnephes pullus is a species of signal flies in the family Platystomatidae.Elassogaster
Elassogaster is a genus of scavenger flies (Diptera) belonging to the family Platystomatidae. They are native to warm regions of Africa, Madagascar and Australia.
They have rounded heads with red eyes, a shiny green thorax and a dark stigma on the wing tips. Adults frequent the vicinity of dung or carcasses, where they walk while constantly waving their wings. The larvae develop in dung.List of Platystomatidae genera
These 129 genera belong to the family Platystomatidae, signal flies. There are at least 1,100 described species in Platystomatidae.Ortalis (fly)
Ortalis is an historic genus of Ulidiid or picture-winged flies, first described by Fallén in 1810. It served as the type genus for the family Ulidiidae, which was called Ortalidae at the time. In 1932, it was pointed out by Adlrich that the name Ortalis was preoccupied by a genus of birds (in family Cracidae) which had been named by Merrem in 1786. The name of the fly family was therefore revised, with some authors calling it Otitidae until Ulidiidae was settled on as standard. The genus itself was found to be paraphyletic, and all of its species have been reassigned to other genera, some in the Ulidiidae, and some in other Tephritoid families. In the following list, the species are organized according to the families and genera to which they have been reassigned.Platystoma
Platystoma is a genus of flies (Diptera) belonging to the family Platystomatidae.Platystoma seminationis
Platystoma seminationis, the dancing "kiss fly", is a species of fly in the family Platystomatidae, meaning big mouths.Platystomatinae
Platystomatinae is a subfamily of flies (Diptera) in the family Platystomatidae (Signal flies).Pogonortalis doclea
Pogonortalis doclea, the boatman fly, is a species of signal flies (insects in the family Platystomatidae).Rivellia
Rivellia is a genus of signal flies (insects in the family Platystomatidae). There are at least 140 described species in Rivellia.Rivellia conjuncta
Rivellia conjuncta is a species of signal flies (insects in the family Platystomatidae).Rivellia coquilletti
Rivellia coquilletti is a species of signal flies (insects in the family Platystomatidae).Rivellia flavimana
Rivellia flavimana is a species of signal flies (insects in the family Platystomatidae).Rivellia inaequata
Rivellia inaequata is a species of signal flies (insects in the family Platystomatidae).Rivellia metallica
Rivellia metallica is a species of signal flies (insects in the family Platystomatidae).Senopterina
Senopterina is a genus of signal flies (insects in the family Platystomatidae). There are about 17 described species in Senopterina.Stalk-eyed fly
Stalk-eyed flies are insects of the fly family Diopsidae. The family is distinguished from most other flies by the possession of "eyestalks": projections from the sides of the head with the eyes at the end. Some fly species from other families such as Drosophilidae, Platystomatidae, Richardiidae, and Tephritidae have similar heads, but the unique character of the Diopsidae is that their antennae are located on the stalk, rather than in the middle of the head as in all other flies.
The stalk-eyed flies are up to a centimeter long, and they feed on both decaying plants and animals. Their unique morphology has inspired research into how the attribute may have arisen through forces of sexual selection and natural selection. Studies of the behavior of the Diopsidae have yielded important insights into the development of sexual ornamentation, the genetic factors that maintain such a morphological feature, sexual selection, and the handicap principle.Tephritoidea
The Tephritoidea are a superfamily of flies. The following families are included:
Pallopteridae — flutter flies
Piophilidae — skippers
Platystomatidae — signal flies
Tephritidae — fruit flies
Ulidiidae (Otitidae) — picture-winged fliesThe Tachiniscinae, formerly ranked as the family Tachiniscidae, are now included in the Tephritidae.
Extant Diptera families