Large robust Bombus-like species, mostly black except for red abdominal apex and sometimes yellow scutellum.
The two species of Eriozona are alone among the Syrphini inresembling closely in appearance certain species of Bombus, e.g. B. lapidarius (Linnaeus). However, in almost all characters except colour pattern the species of Eriozona are very similar to those of Megasyrphus; if colour is disregarded, only the bent vein R4+5 and the more densely pilose metasternum of the latter would serve to separate easily the two genera. The resemblance between the male genitalia of the two genera is remarkable; surstylus, surstylar apodeme, sternite 9, superior lobe, aedeagal base, distal portion of the aedeagus (especially in Megasyrphus and in E. analis) and even the aedeagal apodeme are extremely similar in form in the two genera. If the species of Eriozona had a Syrphus-type colour pattern as do those of Megasyrphus one would almost certainly consider them all congeneric. The conclusion is inescapable that the have been derived, probably rather rapidly, from a form very similar to Megasyrphus, probably in response to selective forces conferring an advantage upon specimens with a resemblance to certain species of Bombus (from Vockeroth 1969).
New description:
MALE.
Head: Face with facial tubercle ventrally, yellow, black lateroventrally, yellow pilose; gena black, black pilose; lunule brown laterally, yellow medially; frontal triangle dark yellow, black posteriorly, black pilose; holoptic, eye densely pilose; vertical triangle black, black pilose; antenna and arista black, basoflagellomere slightly elongate, as long as scape and pedicel together; occiput black, silver pollinose, yellow pilose.
Thorax: Scutum black, dark pollinose, yellow and black pilose; postpronotum bare; scutellum yellowish-bronze, black and yellow pilose, subscutellar fringe complete with black pile. Pleuron black, black pilose; metasternum pilose; calypter brown; plumula brown; halter dark brown; spiracular fringes brown. Wing: Wing membrane and veins yellow, with two dark maculae: one basally, on vein h, the second one on crossveins, from stigma to bm-cu; entirely microtrichose. Alula broad, microtrichose. Legs: Entirely yellow except coxae, trochanter and basal half of femora dark brown. Metacoxa with long black pile anteromedially.
Abdomen: oval, terga 3-5 margined. Terga 1-3 black, with long black pile, except tergum 2 with two patches of white pile lateromedially. Terga 4 and 5 orange-yellow, orange-yellow pilose; sometimes tergum 4 black on anterior margin. Sterna 1-4 black, the rest yellow; sterna 1-2 white pilose, the rest black pilose; male genitalia small.
Synonym:
Eriozona ruficauda Brunetti, 1907: 379.
Eriozona analis Kertesz, 1901.
Kertesz, K. (1901) Neue und bekannte Dipteren in der Sammlung des Ungarischen National-Museums. Természetrajzi Füzetek kiadja a Magyar nemzeti Muzeum 24, 403-432, 1 pl. [1901.10.20]
While it is apparent that Didea, Eriozona and Megasyrphus are closely related there is less agreement on whether the species consigned to these genera should all be grouped under Didea or segregated under the three existing genera (see, for example, Vockeroth and Thompson, 1987; Rotheray and Gilbert, 1989; Vockeroth, 1992). However, recognition of Eriozona as a separate genus carries with it the implication that Megasyrphus should also be regarded as a separate genus, and vice versa, to judge from the information now available (Speight 2010).
Rotheray and Gilbert (1989) recovered Eriozona as sister group of Eupeodes and Scaeva, while Didea and Megasyrphus were resolved together in the same polytomy. A similar placement resulted from the study by Rotheray and Gilbert (1999), when Didea and Megasyrphus were resolved together, and Eriozona as sister group of Dasysyrphus, Paragus, Eupeodes, Scaeva and Ischiodon.
Mengual et al. (2008) recovered Eriozona syrphoides as sister group of Dideoides coquilletti, being Dideopsis aegrota the sister group of both. As a sister group of this clade their results paced Megasyrphus and Didea.
There is no prey record for E. analis, but Eriozona syrphoides was reported feeding on Cinara piceae (Aphididae).
Oriental species known from India, Sikkim, Nepal, Tibet and China.
Larva of Eriozona from Rotheray and Gilbert (1989).
Diagnosis. Up to 15 mm long; rectangular in cross-section; truncate posteriorly; black; vestiture of shiny, black angular papillae; sensilla 1-6 on projections; sensilla 3 on projection larger than those supporting sensilla 2 and 4; body outline serrate; transverse folds deep in resting larva, so that projections supporting sensilla 1 borne on a dorsal ridge; prp (posterior respiratory process) black, broader than long, lightly wrinkled basally, tip with recticulate pattern of carinae; spiracular plates more or less level; dorsal spurs weakly indicated; spiracular slits mounted on orange carinae with more than 0.5 of their length over the sides of the prp; interspiracular ornamentation apparently lacking setae. Recognition features: The large size, serrate outline, black angular papillae and lack of inwardly sloping spiracular plates characterize this genus.
unless otherwise stated