• Source: Diogmites

Diogmites is a genus of mainly neotropical flies in the family Asilidae or robber flies.




Description


Medium to large-sized robber flies (17–48 mm) with mostly minute body hair, thoracal bristles are mostly confined to a row on the mesonotum and two bristles on the scutellum. The mystax is of relatively modest size and is made up of comparatively few bristles, which do not or barely overlap the beak in side view. The antennae have a relatively slender third article that forms over half of the antennal length and carries a single, minute apical hair. Face narrower than the width of one eye. Abdomen slender and sometimes slightly constricted, its posterior end reaches the wing tips or extends past these. Wings are usually clear or only slightly tinted. Body coloration often predominantly straw-yellowish to orange-reddish, in some species darker brown to black. Eye coloration of live animals often includes iridescent green.
Legs comparatively long with prominent bristles, the length of the hind legs often roughly equals the length of the entire body. Forelegs about two-thirds as long as hind legs, with a short but distinctive curved spine at the anterior edge of each tibia. The claws of the hind legs are less than twice as long as the pulvilli. As is typical for Dasypogoninae, the harder cuticle of the prosternum is separated from the neck by an area of flexible cuticle that presumably allows for greater freedom of movement of the forelegs. This feature also occurs in some members of other asilid subfamilies.
As with most asilids, known pupae of Diogmites species have prominent tooth- or hook-like anterior protrusions of the cuticle, which are technically referred to as antennal processes. In this genus there is one undivided pair of anterior antennal processes without any basal bristles, plus three posterior antennal processes




Biology


Adults of Diogmites species hunt as ambush predators, taking off from a resting position on the ground or on branches to intercept other flying insects, or to pounce on perching/crawling prey. After prey capture, these flies will feed in a characteristic posture that has earned this genus the common name of Hanging Thieves: they will hang from plant stems or leaves suspended by one or both front legs, with the other legs holding and manipulating the prey while feeding. Presumably the relatively long legs and reduced prosternum of the genus are part of adaptations to facilitate feeding during this suspended posture.
Hanging thieves should not be confused with predatory scorpionflies of the family Bittacidae which are commonly called Hangingflies and which actually capture flying prey in a suspended posture.
Many observations of the suspended feeding posture of Diogmites were caught on camera, for example Herschel Raney's webpage for Dasypogoninae includes images of D. angustipennis, D. platypterus and D. missouriensis feeding on a variety of insects. Chris Thawley has an interesting video of a feeding adult manipulating a large prey wasp while in hanging posture. Observations of the moment of prey capture are unfortunately not recorded yet in any literature or web resources. Some species can assume an unusual flight posture, with the first and last leg pairs raised high while the middle legs are extended downwards (personal observation of low-flying D. angustipennis males and females in central New Mexico). This might represent a peculiar type of hunting-related behavior more commonly referred to as orientation flights, or perhaps might serve purposes unrelated to hunting, such as a defensive posture to reduce odds of capture by dragonflies or other robberflies, or behavior intended to facilitate latching onto plant stems and leaves for landing.
Robert Lavigne's Predator-Prey Database for the family Asilidae has 443 records of observations for at least 20 species of Diogmites feeding on a wide range of prey, including other asilids as well as dragonflies. Particular species can be selective in prey choice however, for example D. crudelis was observed to feed on Diptera or Hymenoptera in 89 of 93 cases. Very little is known about larval biology, but D. misellus and D. neoternatus larvae were respectively observed and surmised to feed on scarabaeid grubs. Larvae appear to live and pupate in soil, adults emerge after the pupae break through the soil surface to expose the anterior body. Whitney Cranshaw has captured emergence of an adult D. angustipennis in a series of remarkable photographs available at Zipcodezoo. Norman Lavers' Illustrated Field Guide to The Robber Flies of Crowley's Ridge, Arkansas details egg-laying behavior of D. platypterus and includes a more detailed photo of a protruding pupal cuticle.




Taxonomy


Depending on the source, 73 to 77 species are currently recognized in Diogmites:

Diogmites aberrans (Wiedemann, 1821)
Diogmites affinis (Bellardi, 1861)
Diogmites alvesi Carrera, 1949 the author for this species is not Curran, contrary to an erratum that was copied across multiple web databases
Diogmites amethistinus Carrera, 1953
Diogmites angustipennis Loew, 1866
Diogmites atriapex Carrera, 1953 classified instead as Neodiogmites by Alvim et al (2014)
Diogmites aureolus Carrera & Papavero, 1962
Diogmites basalis (Walker, 1851)
Diogmites bellardi (Bromley, 1929)
Diogmites bicolor (Jaennicke, 1867)
Diogmites bifasciatus Carrera, 1949
Diogmites bilineatus (Loew, 1866)
Diogmites bilobatus Barnes, 2010 classified instead as Leptogaster by geller-grimm.de but not GBIF
Diogmites bimaculatus (Bromley, 1929)
Diogmites bromleyi Carrera, 1949
Diogmites brunneus (Fabricius, 1787)
Diogmites castaneus (Macquart, 1838)
Diogmites coffeatus (Wiedemann, 1819)
Diogmites coloradensis (James, 1933)
Diogmites contortus Bromley, 1936
Diogmites craveri (Bellardi, 1861)
Diogmites crudelis Bromley, 1936
Diogmites cuantlensis (Bellardi, 1861)
Diogmites discolor Loew, 1866
Diogmites dubius (Bellardi, 1861)
Diogmites duillius (Walker, 1849)
Diogmites esuriens Bromley, 1936
Diogmites fasciatus (Macquart, 1834)
Diogmites ferrugineus (Lynch & Arribálzaga, 1880)
Diogmites fragilis Bromley, 1936
Diogmites goniostigma Bellardi, 1861
Diogmites grossus (Bromley, 1936)
Diogmites herennius (Walker, 1849)
Diogmites heydenii (Jaennicke, 1867)
Diogmites imitator Carrera, 1953
Diogmites inclusus (Walker, 1851)
Diogmites intactus (Wiedemann, 1828)
Diogmites jalapensis Bellardi, 1861
Diogmites lindigii (Schiner, 1868)
Diogmites lineola (Bromley, 1934)
Diogmites litoralis (Curran, 1930)
Diogmites maculatus Curran, 1934
Diogmites memnon Osten-Sacken, 1887
Diogmites misellus Loew, 1866
Diogmites missouriensis Bromley, 1951
Diogmites neoternatus (Bromley, 1931)
Diogmites nigripennis (Macquart, 1847)
Diogmites nigripes (Bellardi, 1861)
Diogmites nigritarsis (Macquart, 1846)
Diogmites notatus Bigot, 1878 classified instead as Laphystia by geller-grimm.de but not GBIF
Diogmites obscurus Carrera, 1949
Diogmites perplexus Back, 1909
Diogmites platypterus Loew, 1866
Diogmites pritchardi Bromley, 1936
Diogmites properans Bromley, 1936
Diogmites pseudojalapensis (Bellardi, 1862)
Diogmites pulcher (Back, 1909)
Diogmites reticulatus (Fabricius, 1805)
Diogmites rubescens (Bellardi, 1861)
Diogmites rubrodorsatus (Artigas, 1966)
Diogmites rufibasis Bigot, 1878
Diogmites rufipalpis (Macquart, 1838)
Diogmites sallei (Bellardi, 1861)
Diogmites salutans Bromley, 1936
Diogmites superbus Carrera, 1953
Diogmites symmachus (Loew, 1872)
Diogmites tau Osten-Sacken, 1887
Diogmites teresita Lamas, 1972
Diogmites ternatus Loew, 1866
Diogmites texanus Bromley, 1934
Diogmites tricolor (Bellardi, 1861)
Diogmites unicolor Hull, 1958
Diogmites virescens (Bellardi, 1861)
Diogmites vulgaris Carrera, 1947
Diogmites winthemi (Wiedemann, 1821)
Diogmites wygodzinskyi Carrera, 1949




Phylogeny


Although Diogmites is usually considered a member of the subfamily Dasypogoninae, combined analysis of morphological and molecular characters places Diogmites tristis in a clade corresponding to the subfamily Stenopogoninae instead, without however providing direct support for monophyly of this subfamily.




References






External links


Wikispecies page for Diogmites
Diogmites page on bugguide.net

Kata Kunci Pencarian:

• Diogmites jalapensis
• Diogmites properans
• Diogmites pulcher
• Diogmites salutans
• Diogmites unicolor
• Diogmites reticulatus
• Diogmites pulchra
• Diogmites vulgaris
• Diogmites tricolor
• Diogmites texanus
• Diogmites
• Diogmites sallei
• Diogmites texanus
• Diogmites esuriens
• Diogmites neoternatus
• Diogmites angustipennis
• Diogmites properans
• Diogmites discolor
• Diogmites crudelis
• Diogmites platypterus