Study of three genera of the Orthocentrus genus-group (Hymenoptera: Ichneumonidae, Orthocentrinae) in northern Iran

The subfamily Orthocentrinae comprises a diverse group of ichneumonid parasitoid wasps. The species of three genera of the Orthocentrus genus-group (Hymenoptera: Ichneumonidae, Orthocentrinae) was studied in northern Iran: Batakomacrus Kolarov, Plectiscus Gravenhorst and Stenomacrus Förster. A total of 847 specimens of these genera were collected from Alborz, Tehran, Qazvin, Gilan and Mazandaran provinces using Malaise traps during 2010-2011. Nine species including Batakomacrus caudatus (Holmgren, 1858), Plectiscus agilis (Holmgren, 1858), P. minutus (Holmgren, 1858), Stenomacrus carbonariae Roman, 1939, S. curvicaudatus (Brischke, 1871), S. deletus (Thomson, 1897), S. exserens (Thomson, 1898), S. merula (Gravenhorst, 1829) and S. minutissimus (Zetterstedt, 1838) are recorded for the first time from Iran. Their phenology, seasonal abundance, adult emergence period, distribution and altitudinal changes on two northern and southern slopes of the Alborz Mountains of Iran are provided. Our data showed that the Caspian Hyrcanian forests at the northern slope of the Alborz Mountains inhabit a more diverse and higher abundant community of Orthocentrus genus-group than the southern one.