First record of Dasysyrphus tricinctus (Fallén, 1817) (Diptera: Syrphidae) from Iran

: The genus Dasysyrphus Enderlein, 1938 (Diptera: Syrphidae) was studied in Northern Iran. Two species, D. albostriatus (Fallen, 1817) and D. tricinctus (Fallen, 1817) were identified. D. tricinctus is a new record for the fauna of Iran. Diagnostic characters and geographical distribution of D. tricinctus are briefly discussed. Supplementary photographs of the species are provided.

The family Syrphidae (Diptera: Cyclorrhapha), commonly called hover flies or flower flies, comprise about 6000 described species worldwide (Thompson and Rotheray 1998). Up to date, about 40 species of the genus Dasysyrphus Enderlein, 1938 have been described (Huo et al. 2005). In the Palaearctic region, 19 species are listed by Peck (1988), but the taxonomy of several taxa are not well elucidated (Reemer 2002). Three species of this genus, D. albostriatus (Fallén, 1817), D. pinastri (Meigen 1822) and D. tricinctus (Fallén 1817), have been recorded for the Turkish fauna (Saribiyik and Hasbenli 1997) and 12 species have been reported from China (Huo et al. 2005). Thus far, two species of the genus Dasysyrphus have been reported from Iran: D. albostriatus (Fallen 1817) and D. eggeri (Schiner 1862) (Gharali and Gilasian 2002;Dusti 2006). Larvae of Dasysyrphus species feed on aphids (Rotheray 1993). The objective of this study was to determine the occurrence of Dasysyrphus species in the Northern region of Iran.
Material for this study was collected from different habitats of Northern Iran ( Figure 1) using malaise traps with 75% ethanol as the killing and preserving agent. Samples were collected from March to November 2010 and 2011. The specimens were extracted from the malaise traps and sorted weekly. Individuals were then treated with 100% ethanol for 5 minutes followed by hexamethyldisilazane (HMDS) for 30 min and finally placed on a glass plate for drying. The dried specimens were then labeled. Morphological terminology follows Van Veen (2004) and Stubbs and Falk (1983). Vouchers are deposited at the insect collection of the Department of Entomology, Tarbiat Modares University, Tehran. Two species of the genus Dasysyrphus were collected and identified from the study area, including one previously reported species D. albostriatus (Fallén, 1817) (Dousti and Hayat 2006), and one newly recorded species D. tricinctus (Fallén, 1817).

Dasysyrphus albostriatus (Fallén, 1817)
Synonyms: Dasysyrphus confusus (Egger, 1860), Scaeva  General distribution: Ireland eastwards through central and southern Europe (Italy, the former Yugoslavia) to Crete (Speight 2006), Turkey (Sarıbıyık 1997); north Africa (Speight 2006 Figure 2E). Thorax: Scutum shiny black, scutellum yellow with long yellow hairs ( Figure 2D); wing with dark stigma ( Figure  2B); legs mostly yellow, the basal half of femora black. Abdomen: Tergite II with two yellow small spots, tergite III black with two yellow wide bands, tergite IV black with two yellow bands narrower than those of third tergite, tergite V black ( Figure 2D); sternits black, 1 st sternit with two yellow spots, sternite II two yellow bars and a yellow band, sternite III with two yellow small spots and with a yellow band narrower than those of 2 nd sternite, sternits IV +V black ( Figure 2C).
On the basis of characteristics of the male genitalia, Vockeroth (1969) distinguished four species groups in the genus Dasysyrphus: albostriatus species group, the pinastri species group, the tricinctus species group and the venustus species group. Two groups have representatives in Iran. Dasysyrphus albostriatus and D. eggeri (Schiner 1862) belong to albostriatus species group and D. tricinctus belong to tricinctus species group.
Dasysyrphus tricinctus is reported from the entire Balkan Peninsula and occurs mainly in forests. It has only been collected at higher elevations in Macedonia (Krpac et al. 2009). Rotheray (1994) reports that larvae are frequent predators of aphids on Acer pseudoplatanus. Adults are usually found in or near woodlands, along edges and tracksides, where they visit a wide range of flowers (Ball and Morris 2000).