Classification and host plants
Suborder: Brachiceri (Ciclorafi section)
Species: B. bicolor Fallén, 1817
It is present from Europe to Asia, including Siberia and Japan. In Italy it is reported throughout the peninsula. Although there is not much data on distribution, it is likely that it is a species widespread in all mature and humid forests of Faguse Quercus.
The species of the genus Brachyopa resemble at first sight to other Diptera, such as iMuscidi, which is why they are not easily identifiable. Once clarification of the membership of the genus, it is not easy to even determine the species, because some distinctive characteristics are microscopic, making it necessary to use a microscope with many magnifications to identify them.
The fundamental characteristics to distinguish the species are the shape of the sensory points found on the third article over the past year and the more marked featheriness of the artist. The B. bicolor is 5 to 9 mm long and has a small sensory dimple located ventrally on the third antennal segment and medium-plumed arista almost to the apex.
Left, male specimen of Brachyopa bicolor (photo by R. Varrone); right, drawings of the antennas
of some Brachyopa species
Habitat of the species
It prefers mature beech, oak, elm and chestnut forests; it is also found in urban and peri-urban areas where there are mature plants of Acer, Aesculus, Fagus and Quercus suitable for larval development. During the hottest hours of the day, adults fly along the trunks, at a ground height of 1-3 meters, to feed on the sap that flows from the wounds of the plants.
Flight period: adults are from May to July.
Male of Brachyopa bicolor (photo http://syrphidae.3644.co.uk)
Description and ecology of the larva
Of elongated sub-oval shape characterized by a well-developed anal siphon and spines on the dorsal and lateral part of the body; the posterior spines, close to the anal siphon, are larger and more branched. It lives in the humid hollows of trees, in old stumps and especially on exudates of wounded plants.
Larva of Brachyopa bicolor (photo https://www.researchgate.net)
The Sirphids (Diptera): biodiversity and conservation
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