Three new records of Pteromalidae (Hym., Chalcidoidea) for insects’ fauna of Iraq

Introduction

The collection and identification of the wasps of the family Petromalidae in Iraq began by Waterson (1922) with the description of the parasitoid wasp Pachyneuron crassiculme Waterston, 1922. After Waterston (1922) other researchers such as Al-Azawi (1971), Herting (1976), Abdul-Rassoul, (1990), Abdul-Rassoul et al. (1999), Al-Obaidy et al., (2019), Hassan (2021) and Bandyan et al. (2021) reported new records of pteromalid wasps from Iraq through their investigations. The names of the genera and species found by these researchers are provided in the checklist published by Rahmani et al, (2022). More recently, Alsendi et al, (2024) have described a new species of Norbanus Walker, namely Norbanus tabatabaeii Lotfalizadeh & Alsendi, 2024 and reported five genera and six species of pteromalid wasps for the first from Iraq. The aim of this study is to discover and identify new records of pteromalid wasps in Iraq.

Materials and methods

 Specimens were collected using sweep nets from the okra fields and Adjacent areas of Basrah/ Basrah province (Fig. 1), Iraq and preserved in 70% ethanol until further processing. The specimens were prepared and mounted. For card-mounting, rectangular cards were used, with water-soluble glue applied to fix the specimens onto these cards (Noyes, 1982). Specimens were documented using a 14-megapixel Touptek L3CMOS-14000KPA digital microscope camera, mounted on a Wild M5 Stereomicroscope from Wild Heerbrugg M5 stereomicroscope. Image processing and assembly were performed out using Adobe Photoshop. Identification was carried out using the taxonomic key by Ferrière (1959), Narendran & van Harten (2007) and Shojaey et al. (2021). The morphological terminology follows Gibson (1997). Voucher specimens were deposited at the Insect Collection of the Plant Protection Department of Urmia University (PPDUU) for future reference.

Results

Our sampling yielded to collection of 17 female and 7 male specimens of pteromalid wasp which falls to two genera and three species as follow. These have not been recorded from Iraq before.

Genus Pachyneuron Walker, 1833

Pachyneuron gibbiscuta Thomson, 1878 (Fig. 2)

Material examined

IRAQ - Basrah governorate, Basrah, 30°55'56.6" N, 47°14'00.6" E, 3 m a.s.l., 23.x.2024; F. Alag leg. 5♀♀

Diagnosis

Female; Body metallic (Fig. 2A); antennal scape testaceous except for apical two-thirds in inner part; pedicellus and flagellum dark brown. Antenna with funiculars subquadrate; head and vertex compared to other species in this genus less broad and gena less sharp (Fig. 2A/red arrow). Mesonotum highly elevated with black setae. Fore wing with marginal vein widened distad (red arrow), and postmarginal vein longer than marginal vein (Fig. 2B). Propodeum with complete plicae and short nucha; petiole distinct and transverse with smooth sculpture dorsally. Abdomen short and ovate (Fig. 2A).

Distribution

Austria, China, Czech Republic, former Czechoslovakia, Germany, Sweden (UCD Community, 2023), Iran (Shojaey et al., 2021), Turkey (Doğanlar, 1986).

Hosts

Pachyneuron gibbiscuta is reported as parasitoid of Myzus cerasi (Fabricius,1775) and hyperparasitoid of Aphidius Esenbeck (Braconidae), 1818 (UCD Community, 2023).

Fig. 1. Okra field and adjacent area in Basrah environs

Fig. 2. Pachyneuron gibbiscuta Thomson, 1878, female: A.  General habitus, lateral view, head and antennae (red arrow); B. fore wing 

Genus Sphegigaster Spinola, 1811

Sphegigaster cuscutae Ferrière, 1959 (Figs. 3, 4)

Sphegigaster cuscutae Ferrière, 1959: 98, ♀♂. – Germany.

Material examined

IRAQ - Basrah Province, Basrah, 30°55'56.6" N, 47°14'00.6" E, 3 m a.s.l., 23.x.2024; F. Alag leg. 5♀♀2♂♂

Diagnosis

Female; Body color dark to metallic green (Fig. 3A); antennal scape yellowish; pedicellus fulvous; flagellum bronzy to dark brown; legs yellow except for coxae which are concolorous with thorax (Figs. 3A, C). Head transverse and entirely punctate; ocelli form an obtuse triangle; antennal insertion at the middle of face; pedicellus twice as long as wide; first funicular equal to pedicellus in length and width. Mesonotum wider than long (Fig. 3D); notauli indicated only anteriorly; axillae sculpture same as mesoscutellum; propodeum entirely reticulate and without median cariana; petiole widened anteriorly and narrowed posteriorly, approximately 1.5 times longer than hind coxa. Fore wing large and hyaline; marginal vein twice as long as stigmal vein (Fig. 3B); hind wing with narrowly rounded apex. Abdomen with first segment large and triangular, subsequent segments are very short (Fig. 3D).

Male; Similar to female but smaller (Fig. 4). Antenna elongate and dark; pedicellus only slightly longer than wide; funiculars 3–4 times longer than wide and densely setose; clava as long as the preceding two funiculars combined. Pronotal denticles more pronounced and sharper than in female. Petiole longer and narrower.

Distribution

Widespread in Europe, Iran (Hasani et al., 2011), Morocco (Klein, 1995), Yemen (Narendran & van Harten, 2007).

Host

 The hosts of this species in Iraq are unknown. According to Bouček (1961) S. cuscutae is a primary parasitoid of Melanagromyza cuscutae Hering (Diptera: Agromyzidae) on Cuscuta lupuliformis Krock. (Convolvulaceae) and Spencer (1973) stated that the high rate of parasitism to be an important limiting factor for M. cuscutae as a biocontrol agent of C. lupuliformis.

Sphegigaster nigricornis (Nees, 1834) (Fig. 4, 5)

Chrysolampus nigricornis Nees, 1834:133, Lectotype ♀. – HDOU, Germany.

Material examined

 IRAQ - Basrah Province, Basrah, 30°55'56.6" N, 47°14'00.6" E, 3 m a.s.l., 23.x.2024; F. Alag leg. 7♀♀5♂♂

Fig. 3. Sphegigaster cuscutae Ferrière, 1959, Female: A.  General habitus, lateral view; B. fore wing; C. Antennae; D. Dorsal view

Diagnosis

Female; Body color dark to metallic green (Figs. 5A, C); antenna with scape and pedicellus metallic green and flagellum bronzy to dark brown (Fig. 5B); legs with coxae concolorous to thorax, femora in the first half metallic green and in the second half yellowish same as the remaining parts of legs (Fig. 5A). Antenna short with scape reaching middle of the median ocellus (Fig. 5B). Thorax very finely reticulate and somewhat shiny. Propodeum with sculpture stronger than thorax and without median carina; petiole slender and reaching far beyond the tips of the hind coxa. Wings hyaline (Figs. 5A and 6B). Abdomen smooth and shiny, ventral side swollen at the base (Fig. 5C).

Male; Similar to female but smaller and often exhibit a greener metallic body coloration (Figs. 6A, C); legs paler, fore and mid femora with dark parts testaceous (Fig. 6A). Antennal scape shorter and three quarters the length of an eye; pedicellus shorter; funiculars subequal n length; clava 3 times as long as broad (Fig. 6D). Spur of mid tibia relatively shorter. Petiole longer and slenderer than in females (Figs. 5C and 6A).

Distribution

 Widespread in Eastern and Western Palaearctic (UCD Community, 2023), Middle East /Iran (Lotfalizadeh & Gharali, 2008; Shojaey et al., 2021).

Diagnostic similarities and diffrences of S. cuscutae and S. nigricornis

Similarities

 Both species have a dark to metallic green body, large and hyaline wings, propodeum lacks median carina as a key generic feature, and in both species, males are smaller than females, coxae are concolorous with the thorax, male petiole is longer and slender than that of the female.

Fig. 4. Sphegigaster cuscutae Ferrière, 1959, Male:  General habitus, lateral view

Differences

Diagnostic differences between S. cuscutae and S. nigricornis were provided in Table 1. In addition, in S. cuscuta mesonotum wider than long, thoracic sculpture coarser, notauli only indicated anteriorly, propodeum entirely reticulates, petiole widened anteriorly and narrowed posteriorly and about 1.5×longr than hind coxa but in S. nigricornis, thorax very finely reticulate and shiny, propodeal sculpture stronger than thorax, Petiole very slender extends far beyond the tips of the hind coxa.

Hosts

Some species of Agromyzidae (Diptera), especially in the genus Melanagromyza Hendel are the primary host of S. nigricornis (UCD Community, 2023).

Discussion

In the genus Pachyneuron Walker petiole longer than broad; gasteral tergit 1 enlarged; clypeal margin slightly produced; notauli shallow; antennae inserted at center of face; funiculars wider than long; postmarginal vein obviously longer than marginal and submarginal vein (Ko et al., 2018). It is the cosmopolitan genus of ptromalid wasps which consists of 62 valid species (UCD Community, 2023). Among them, 21 species have been reported from the Middle East and 13 species from Iran (Rhamani et al., 2022). Various species of the genus Pachyneuron are mostly the hyperparasitoids of the insects from the suborder Sternorrhyncha (aphids, coccids and psyllids).

Fig. 5. Sphegigaster nigricornis (Nees, 1834), Female: A.  General habitus, lateral view; B. head and antennae, frontal view; C. thorax, petiole and abdomen, dorsal view

Fig. 6. Sphegigaster nigriornis (Nees, 1834), Male: A.  General habitus, lateral view; B. head and antennae, frontal view; C. thorax, petiole and abdomen, dorsal view

However, some species are also primary or secondary parasitoids of Diptera including Chamaemyiidae, Agromyzidae, Chloropidae, Cecidomyiidae, Coleoptera (Coccinellidae), Neuroptera (Chrysopidae) and eggs of Lepidoptera (Gibson, 2001; Dzhanokmen, 2009; Xiao et al., 2009). The hosts of this species in Iraq and Iran (Shojaey et al., 2021) as a neibouring country are unknown. To date, three species of Pachyneuron including Pachyneuron crassiculme Waterston, 1922 (Waterston, 1922), P. aphidis (Bouché, 1834) (Bandyan et al., 2021) and P. muscarum (Linnaeus, 1758) have been reported from Iraq.  With the collection and identification of P. gibbiscuta from the Basrah region, the number of known Pachyneuron species in Iraq increases to four species.

    The genus Sphegigaster is defined by the following combination of characters: head transvers, vertex broad, pronotum short and margined, anterior margin of pronotum often with five small teeth especially in males, parapsidal grooves on mesonotum short and incomplete, marginal vein narrow in fore wing, abdomen with large second and third segments. They are small dipteran parasitoids and undoubtedly have a wide distribution and abundance in nature, however, they are less well known (Ferrière, 1959). Only one species of the genus Sphegigaster namely S. orobanchiae Kurdjumov, 1912 was previously recorded from the Iraq (Mekhlif & Abdul-Rassoul, 2002). In this study, two species of genus Sphegigaster namely, S. cuscutae and S. nigricornis are recorded from Iraq for the first time. With the addition of these two species the species number of genus Sphegigaster in Iraq increases to three species. The species of the family Pteromalidae reported from Iraq are presented in Table 2.

Table 2 - List of reported Pteromalidae species in Iraq

In the neighbouring countries of Iraq, four species of of them namely Sphegigaster brevicornis (Walker, 1833), Sphegigaster pallicornis (Spinola, 1808), Sphegigaster pedunculiventris (Spinola, 1808) (Doğanlar, 1985) and     Sphegigaster orobanchiae Kurdjumov, 1912 (Çikman & Doğanlar, 2006) were reported form Türkiye and nine species of this genus including Sphegigaster cuscutae Ferrière, 1959 (Hasani et al., 2011), Sphegigaster ineus Mitroiu, 2008 (Lotfalizadeh et al., 2015; Shojaey et al., 2021), Sphegigaster mutica Thomson, 1878 (Dehdar & Madjdzadeh, 2016), Sphegigaster nigricornis (Nees, 1834) (Lotfalizadeh & Gharali, 2008; Shojaey et al., 2021),  Sphegigaster orobanchiae Kurdjumov, 1912 (OILB, 1971; Modarres Awal, 2012), Sphegigaster pedunculiventris (Spinola, 1808) (Shojaey et al., 2021), Sphegigaster persiana Mitroiu & Madjdzadeh, 2011(Mitroiu et al., 2011). Sphegigaster stepicola Bouček, 1965 (Modarres Awal., 2012), Sphegigaster truncata Thomson, 1878 (Mitroiu et al., 2011). But no species of this genus have been reported from Kuwait or Syria. Given the geographical expansion and climatic diversity of Iraq, there are certainly many more species of the genus Sphegigaster distributed in Iraq. Their discovery and identification require extensive sampling from different regions of Iraq.

Author's Contributions

Faraj Alag: Collection, Investigation, Draft preparation and Final review. Younes Karimpour: Conceptualization, Methodology, Primary Identification, Investigation, Draft preparation, Final review and edit, Visualization, Supervision and Project administration. Ali Dhareb Shaaban: Conceptualization, Methodology, Final review, Visualization, Supervision, Project administration, and Funding acquisition.

Author's Information

Funding

This research received no specific grant from any funding agencies.

Data Availability Statement

The specimens examined in this study are deposited in the second author's collection at the Department of Plant Protection, Faculty of Agriculture, Urmia University, Urmia, Iran and are available by the curator upon request.

Acknowledgments

 We would like to offer our special thanks to Dr. Hosein Lotfalizadeh Insects Taxonomy Research Department, Iranian Research Institute of Plant Protection (IRIPP), AREEO, Tehran, IRAN for identificathion of specimens.

Ethics Approval

All applicable international, national, and institutional guidelines for the care and use of animals were followed. This article does not contain any studies with human participants performed by the author.

Conflict of Interest

The authors declare that there is no conflict of interest regarding the publication of this paper.

Generative AI statement

The authors declare that no Gen AI was used in the creation of this manuscript.