Brachyopa (Hammerschmidtia) ferruginea (Fallen)
B. ferruginea is classified as endangered and is known only from one or two sites in Scotland (Shirt, 1987).
Brachyopa (Hammerschmidtia) ferruginea (Fallen, 1817).
Fallen, C.F. (1816-1817) Syrphici Sveciae. Pp. 1-14 [1816.06.08], 15-22 [1816.06.08], 23-30 [1817.05.10], 31-42 [1817.05.20], 43-54 [1817.05.21], 55-62. [1817.05.22] Berlingianis, Lundae [= Lund].
The closely similar species Brachyopa (Hammerschmidtia) ingrica is also recorded from European parts of Russia and may occur more widely in Europe. The arista is plumose in B. ferruginea but short haired in B. ingrica. These two species may be distinguished using the keys in Violovitsh (1986), who also figures their male terminalia (Speight 2010).
Adults visit white umbellifers, Crataegus, Ranunculus, male Salix (Speight 2010).
Flight period for European specimens is from the end of May to the end of July.
Brachyopa (Hammerschmidtia) ferruginea ranges from Fennoscandia south to northern France; Great Britain (Scotland) east through northern and central Europe (south as far as Roumania) into Siberia and on to the Pacific. In North America this species is known from Alaska to Quebec, south to Arizona and New Mexico (Speight 2010; Thompson 2010).
The adults may be found sitting on the trunks of Betula and old Populus tremula, or on logs and stumps in the vicinity of P. tremula (Speight 2010).
Preferred environment: forest, coniferous (Pinus) or deciduous (Betula, Quercus) forest with overmature
Populus tremula (Speight 2010).
Larva of B. ferruginea was described and figured by Rotheray (1991) from larvae and puparia collected from sappy material under the bark of recently fallen aspen (Populus tremula). They may be distinguished from larvae of some Brachyopa species by the key in Rotheray (1994). Krivosheina (2003) provides a key for separation of the larva of B. ferruginea from the larva of B. ingrica. Rotheray and MacGowan (2000) suggest that stands of aspen of less than 5 ha extent are unlikely to be able to maintain populations of this species, due to its requirement for a constantly renewed resource of recently-dead trees (from Speight 2010).
Third instar larva (Rotheray 1991).
Overall appearance. A dorso-ventrally flattened larva lacking blotches and coated in setae with a tapering anal segment, an elongate prp (=posterior respiratory process) and gradually elongating projections along the lateral margins.
Length. 9-12mm; width: 4-5 mm; flattened dorso-ventrally (about twice as broad as high), slightly tapering anteriorly, tapering posteriorly; mandibles and mandibular lobes internal; lateral lips with base coated in spicules and tip coated in fine setae; blotches absent on abdominal segments; abdominal segments 1-7 coated in setae up to 0-24 mm long; ventral surface coated with backwardly directed spicules, less so on the mesothorax and anal segment; anterior fold of the prothorax with a broad (>75% of space coated) spicule band reaching to sensilla 1 and comprising >5 rows; anterior spiracles present; prolegs, as weakly produced transverse ridges, present on abdominal segments 1-6 and the mesothorax with up to five short and indistinct crochets per proleg, crochets absent or reduced in number on abdominal segment 6; sensilla 1-7 on each abdominal segment on projecting basal papillae up to 0.36 mm long; integumental fold separating sensilla 1 from 2 so that sensilla I lies anterior to 2; each sensilla with up to five surrounding setae; anal segment about twice as long as sixth abdominal segment; dorsally anal segment consisting of two tapering folds, the first with two pairs of lappets and the second with a single pair; posterior respiratory process: length: 1.8 mm; width: at base 0.44 mm, at tip 0.36 ram; basal two-thirds matt with fine ridges, apical third smooth and shining; three pairs of spiracular slits.
The larva of B. ferruginea can be separated from those of Brachyopa species which it closely resembles by its coating of setae, absence of blotches and on abdominal segments 1-6 sensilla 1 is separated from sensilla 2 by an integumental fold such that sensilla 1 is anterior to sensilla 2.