The genus Choeras Mason, 1981 (Hymenoptera: Braconidae, Microgastrinae) in northern Iran is studied taxonomically. Specimens were collected using Malaise traps during 2010 and 2011. A total of five species were identified, three being new species which are described and illustrated: Choeras formosus Abdoli & Fernandez-Triana sp. nov., C. fulviventris Fernandez-Triana & Abdoli sp. nov. and C. qazviniensis Fernandez-Triana & Talebi sp. nov. Two species (i.e., C. taftanensis and C. tiro) are new provincial records. The number of Choeras species in Iran is now raised to seven. An identification key to all West Palaearctic species of Choeras is provided.

The present study is based on the genus Cotesia Cameron,1891 collected from Khuzestan Province in the Southwestern part of Iran during 2016–2017. Nine species (+200 specimens) of the genus Cotesia were collected and identified. We recognised three new species, which we describe and illustrate here: Cotesia elongata Zargar & Gupta sp. nov., C. khuzestanesis Zargar & Gupta sp. nov. and C. zagrosensis Zargar & Gupta sp. nov. Two species are recorded for the first time from Iran: Cotesia cynthiae (Nixon, 1974) and C. glabrata (Telenga, 1955). A faunistic list with species distribution in Iran, a modified key to include the new species and brief diagnoses for the new records from Iran are provided.

The performance of two aphid parasitoids, Aphidius colemani Viereck and Aphidius matricariae (Haliday), against Aphis gossypii Glover on greenhouse c

Functional response and mutual interference are the most important behavioural characteristics that reveal different aspects of host–parasitoid interactions. In this study, functional response and mutual interference of the parasitoid wasp, Diaeretiella rapae (M’Intosh) attacking the cabbage aphid, Brevicoryne brassicae (Linnaeus) were investigated. Logistic regression was used to distinguish the shape of the functional response (type II or III). Nonlinear least-square regression was used to estimate the attack rate (a) and handling time (Th). Nicholson’s model and linear regression were used to determine per capita searching efficiency and interference coefficient, respectively. Logistic regression suggested a type II response on B. brassicae nymphs. The per capita parasitism decreased significantly from 80.80 (67.33%) to 11.85 (9.88%) as parasitoid densities increased from 1 to 8 females. Consequently, the per capita searching efficiency decreased significantly from 1.173 to 0.205 as parasitoid densities increased from 1 to 8. The rate of parasitism increased as the host density increased from 2 to 50, and subsequently the parasitoid density decreased from 8 to 1. Therefore, different host–parasitoid ratios could affect the efficacy of D. rapae.