A STUDY OF THE PTEROMALIDAE ( HYMENOPTERA : CHALCIDOIDEA ) FROM WESTERN AND NORTHWESTERN IRAN

Abstract Pteromalids are small parasitic koinobiont wasps that grow on immature stages of other insects. Thus, they play an important role in most ecosystems, mainly as secondary or tertiary consumers. In the conducted surveys of pteromalid fauna in western and northwestern Iran, 37 parasitoids and hyperparasitoid species from 32 genera were collected and are presented here with the host records.


INTRODUCTION
The Pteromalidae is one of the largest families of Chalcidoidea (Hymenoptera) containing over 3506 described species worldwide.The family is distributed in all biogeographical areas of the world and shows great diversity in morphology and biology.The great majority of Pteromalidae are primary or secondary parasitoids that attack a large number of insects at various stages of host development.Only a few pteromalids are phytophagous.Some of them develop in the seeds of plants, others are gall makers and still others develop as inquilines in galls caused by other insects.They play an important role in the biological control of serious insect pests in the field and many of them are employed successfully in biological control programs all over the world (Bouček and Heydon, 1997;Sureshan and Narendran, 2003;Gibson, 2009).
Pteromalidae is defined only by the absence of features defining other chalcidoid families and it may be paraphyletic in respect to a number of these; the limits and placement of this family are simply unknown.Thirty-one subfamilies are currently recognized within Pteromalidae (Noyes, 2003), although inclusion and exclusion of many subfamilies is still highly uncertain.Few comprehensive phylogenetic studies have been conducted at the subfamily or tribal level, making the coding of characters and choice of exemplars difficult in higher-level analyses (Gibson, 2003;Desjardins, 2007).

MATERIALS AND METHODS
The specimens were collected using three methods: sweeping net, Malaise trap and rearing of various hosts by the authors and other researchers.The samplings were conducted in 19 localities (Ahar, Ardabil, Aslandooz, Bijar, Bilehsavar, Divandarreh, Jolfa, Kaleybar, Khodafarin, Khoy, Maco, Mahabad, Maragheh, Oshnavieh, Ourmieh, Piranshahr, Ravansar, Sanandaj and Tabriz) related to 4 provinces including, Ardabil, East Azerbaijan, Kermanshah, Kordestan and West Azerbaijan.In order to obtain the parasitoids or hyperparasitoids, infested plant parts were placed in plastic bags under laboratory conditions (25±2ºC, 75±5 RH%, 16: 8 L: D) and adult emergence was monitored.Additionally, the immature life stages of different insects were collected from fields and forests and were kept at the abovementioned optimum conditions for the emergence of the probable parasitoids or hyperparasitoids inside.The emerging adult parasitoids were transferred into vials of 70% ethanol and were examined with a stereoscopic binocular microscope.The classification method was used according to Graham (1969), Wall (1972) and Bouček and Rasplus (1991).

RESULTS
A total of 37 pteromalid species from 32 genera were collected from west and northwestern Iran.The list of species with the host of some species is given below.

DISCUSSION
The collection of a total of 107 specimens from only some regions of west and northwestern Iran indicates the high diversity of pteromalid wasps in these parts.All the hosts of Pteromalidae listed in this paper are related to 5 orders including Coleoptera, Diptera, Hymenoptera, Lepidoptera and Hemiptera, with 12, 7, 5, 2 and 2 species as the hosts of Pteromalidae.Among the coleopteran hosts, three families, Buprestidae, Scolytidae and were the most numerous with 5, 4 and 3 species, respectively.Since almost all sampled regions of this research were forests areas, the mentioned host records are the pests of different tree species.Although diverse and interesting parasitoid species were collected, continuation of the determination of the pteromalid fauna in other parts of Iran and even in the sampled regions in this paper is strongly suggested.Several regular samplings must be conducted in different regions of Iran to determine the fauna of Iranian Pteromalidae.