Ephedrus hyadaphidis Kocic & Tomanovic

Kocic, Korana, Petrovic, Andjeljko, Ckrkic, Jelisaveta, Mitrovic, Milana & Zeljko Tomanovic,, 2019, Phylogenetic relationships and subgeneric classification of European Ephedrus species (Hymenoptera, Braconidae, Aphidiinae), ZooKeys 878, pp. 1-22 : 1

Ephedrus hyadaphidis Kocic & Tomanovic sp. nov. Fig. 3

Material.

Holotype ♀ from Montenegro: Durmitor-Sušica, 27.07.2012, reared from Hyadaphis foeniculi on Sanicula europaea . Paratypes: 2♂ (slide mounted) from Montenegro: Durmitor-Sušica, 27.07.2012, reared from Hyadaphis foeniculi on Sanicula europaea . 3♀6♂ from Montenegro: Crno jezero, 20.06.2004, from Hyadaphis foeniculi on Lonicera xylosteum . 5♂ from Montenegro: Durmitor-Sušica, 22.07.2004, reared from Hyadaphis foeniculi on Sanicula europaea . 5♀9♂ (2♀ mounted) from Croatia: Plitvička jezera-Milanovac, 20.06.2015, from Hyadaphis foeniculi on Anthriscus sylvestris .

Diagnosis.

The new species belongs to E. plagiator species group, due to fore wing venation. It is differentiated from other Ephedrus species by possessing considerably short first flagellar segment; F1 is 2.40-2.65 as long as wide (the closest ratio is in E. nacheri , 3.05-3.7). The new species is most closely related to E. plagiator. Beside the shorter F1, it can be distinguished from E. plagiator by a smaller number of longitudinal placodes on F2 (2-3 compared to 4-6) and wider pterostigma (4.15-4.35 compared to 4.4-4.75 in E. plagiator ). The new species is a specialised parasitoid of Hyadaphis foeniculi , occurring in the Balkan Peninsula.

Description.

Female. Head ( Fig. 3A ). Eyes medium sized, oval, prominent and sparsely haired. Clypeus somewhat convex, bearing eight long setae. Frons with medium number of setae. Tentorial index 0.6-0.7. Tentorial pits deep. Malar space to longitudinal eye diameter ratio 0.4. Maxillary palps with four palpomeres, labial with two, all of them densely setose. Antennae 11-segmented, filiform, with semi-erect setae that are subequal to 2/3 of the flagellar segment diameter ( Fig. 3B ). First flagellar segment (F1) 2.41-2.67 times as long as wide, bearing 2-3 longitudinal placodes ( Fig. 3C ). F2 2.31-2.65 times as long as wide, with 2-3 longitudinal placodes. Number of longitudinal placodes on the remaining seven flagellar segments remains low (F3 2-4, F4 2-4, F5 3-5, F6 3-6, F7 4-6, F8 4-6, F9 4-6). F8 and F9 separated, but due to dense hairs may not seem that visible. Mesosoma. Mesoscutum with slightly crenulated notaulices distinct only in anterior part ( Fig. 3D ). Along mesoscutum two rows of sparse setae present. Propodeum areolated with regular carinae and pentagonal central areola ( Fig. 3E ). Upper and lower areolae with 2-4 setae. Forewing ( Fig. 3H ). Forewing length 1.6 mm, width 0.6 mm. Pterostigma 4.15-4.35 as long as wide. Pterostigma width to r vein ratio (ptw/r) 1.62-1.87. 3Rsa/r-m and 3Rsb/3Rsa vein ratios 1.62-1.70 and 1.97-2.14, respectively. Vein 2Rsa not visible in first third, therefore may appear shorter than it is. 3Rsa and 2Rsa vein ratio 1.1-1.2. Metasoma. Petiole slender, 2.05-2.15 as long as wide at spiracle level ( Fig. 3F ). Central carina is prominent, while dorso-lateral carinae are slightly distinct. Posterior lateral excavations visible. Ovipositor sheaths elongated, 3.3 times as long as wide, bearing sparse setae along the surface ( Fig. 3G ). Colour. Head and mesoscutum brown, the rest of the mesosoma and petiole yellowish brown. Mouthparts brown. Scape and pedicel brown, F1 with yellow ring at the base, remaining flagellar segments brown. Metasoma and ovipositor sheets brown. Legs yellowish. Body length 1.8 mm. Male. Eyes slightly more convex than in female. Head with sparse hairs. Tentorial index 0.45. Malar space to longitudinal eye diameter ratio 0.3. Antennae 11-segmented, with long setae along the surface, almost equal to flagellum diameter. F1 and F2 2.45 times as long as wide, both with 2-3 longitudinal placodes. F2 subequal to F1. Maxillary palps with four palpomeres, labial with two. Mesoscutum like in female. Propodeum with pentagonal central areola and regular carinae. Pterostigma slightly wider than in female, with the length to width ratio 3.8-3.9. Vein ratios Ptw/r, 3Rsa/r-m and 3Rsb/3Rsa are 1.8-1.9, 1.85-1.90 and 1.8-1.95, respectively. 3Rsa to 2Rsa vein ratio is 1.3-1.4. Petiole 2 times as long as wide at spiracle level. Petiole with visible central and lateral carinae. Colour. Same as in female.

Etymology.

Name of the species is derived from its aphid host, Hyadaphis foeniculi .

Distribution.

The current species distribution is Balkan Peninsula.

Depositories.

Holotype is slide mounted and deposited in the collection of the Institute of Zoology, Faculty of Biology, University of Belgrade. Paratypes collected in National Park Plitvice, Croatia are deposited in the Croatian Natural History Museum, Zagreb, Croatia. The remaining paratypes are deposited at the Institute of Zoology, Faculty of Biology, University of Belgrade.

Synonymies.

The molecular phylogenetic analysis clustered E. dysaphidis together with E. cerasicola , with the genetic distance ranging from 0.0% to 1.6%. We performed a detailed morphological examination of all available material of both species in order to test the obtained molecular results. Ephedrus dysaphidis is a species from plagiator species group, described in the study by Tomić et al. (2005). Authors differentiated it from other species in this group by number of longitudinal placodes on F1 (1-2, rarely 3) and F2 (2-3, rarely 4) and shorter petiole (1.94-2.20 times as long as wide). The colour of scapus, pedicel and the ring at the base of F1 is stated as brownish to yellow. It is a parasitoid of aphids from genus Dysaphis Börneron on Malus domestica Borkh. While studying morphology of many additional populations of E. dysaphidis and E. cerasicola , we found numerous overlapping characters. In the description of E. cerasicola , Starý (1962) states that F1 is more than three times as long as wide, while in the paper of Tomić et al. (2005) the length/width ratio of E. dysaphidis is 3.8-4.6. Furthermore, F1/F2 length ratio is also overlapping in both species (in E. cerasicola F1 is longer by 1/3 than F2 and in E. dysaphidis that ratio is 1.28). Propodeum in both species is with a pentagonal areola, having the same number of setae on upper and lower areolae. Additionally, pterostigma in E. cerasicola is more than four times as long as wide; in E. dysaphidis this ratio varies between 4.1-4.7. Finally, petiole in E. cerasicola is less than twice as long as wide, while in E. dysaphidis , according to the authors, this ratio is 1.94-2.20. However, our studied material of both species showed that the length to width ratio at the spiracle level of E. cerasicola and E. dysaphidis is 1.97-2.1 and 1.90-2.18, respectively, thus also overlapping. The only character that differs in two descriptions of species is the number of longitudinal placodes on F1 and F2 flagellar segments, which is 0 and 2 in E. cerasicola and, as mentioned above, 1-2(3) and 2-3(4) in E. dysaphidis , respectively. However, we found specimens from the same sample (that were first identified as E. dysaphidis based on the aphid host Dysaphis plantaginea Passerini, 1860 on Malus domestica ) having a different number of longitudinal placodes that varied from F1:0, F2:1 to F1:1, F2:3. Moreover, in the revision of the genus Ephedrus Gärdenfors (1986) states that the number of longitudinal placodes in F1 and F2 for E. cerasicola is 1 and 2-3, respectively. One more distinction between the species was the colour of scape, pedicel and F1 and F2. In E. cerasicola scape, pedicel, F1 and part of F2 are yellow brownish ( Starý 1962) or can be with scape yellowish to brown, pedicel and at least base or the entire F1 yellow, while F2 is yellowish at base ( Gärdenfors 1986). While examining the material of both species we found various gradations of scape, pedicel, F1 and F2 colour, mainly following the description of Starý (1962) and Gärdenfors (1986). Although important morphological variability exists within E. cerasicola host associated lineages, after examining all the available data we here synonymise E. dysaphidis as a junior synonym of E. cerasicola .

Material examined. E. dysaphidis : Holotype ♀ from Serbia: Belgrade, 08.05.1995, reared from Dysaphis sp. on Malus domestica . Paratypes 3♀ from Serbia: Belgrade, 08.05.1995, reared from Dysaphis sp. on Malus domestica . 1♀ from Serbia: Belgrade-Radmilovac, 22.04.1992, reared from Dysaphis sp. on Malus domestica . 3 ♀ Serbia: Belgrade-Zemun, 22.04.2014, from Dysaphis devecta Walker on Malus sp. 2 ♀ Serbia: Belgrade, 24.04.2014, from Dysaphis devecta on Malus sp. E. cerasicola : 1♀ from Montenegro: Zminje jezero, 04.08.1982. 1♀ Serbia: Belgrade-Crveni krst, 14.06.1997, from Myzus cerasi Fabricius 1775 on Prunus cerasus L. 1♀ from Serbia: Mladenovac, 11.06.1990. 1♀ from Serbia: Belgrade-New Belgrade, 17.06.1993, from Phorodon humuli Schrank, 1801 on Prunus cerasifera 1♀ from Serbia: Kopaonik, 05.07.1997, from Brachycaudus helichrysi Kaltenbach, 1843 on Myosotis sp. 2♀1♂ from Serbia: Subjel, 01.05.2017., from Dysaphis pyri Boyer de Feonscolombe, 1841 on Pyrus communis . 4♀ from Belgium: from Dysaphis plantaginea on Malus sp.

Ephedrus blattnyi is a specialised parasitoid described from one finding in the Czech Republic, reared from Pterocomma ringadhli (junior synonym of Pterocomma rufipes Hartig, 1841) on Salix caprea . Several authors during previous years questioned the validity of E. blattnyi species status. After the examination of type specimens Gärdenfors (1986) stated that they are extraordinarily similar to E. plagiator and that it is possible that they represent aberrant specimens of E. plagiator due to an unusual aphid host. Furthermore, Koponen and Halme (1993) reported that they collected specimens fully corresponding to the E. blattnyi redescription ( Gärdenfors, 1986). However, the authors didn`t include them in the paper, since the distinguishing characters were not reliable. Finally, Tomanović (2000) states, while reporting the finding of specimens corresponding to E. blattnyi , that it is very similar to E. plagiator and E. prociphili . We analysed specimens from P. rufipes which morphologically corresponded to the description of E. blattnyi reared from P. rufipes aphid host on Salix retusa . Molecular analysis of COI clustered E. blattnyi within the E. plagiator , with the molecular distance ranging from 0.2% to 0.7%. Therefore, we conclude that E. blattnyi represents a morphotype of E. plagiator and assign it a status of junior synonym.

Figures

Figure 3. Ephedrus hyadaphidis Kocic & Tomanovic, sp. nov., female, scanning electron microscopy A Head, anterior view B Antennae, lateral view C First and second antennal segments, lateral view D Mesoscutum, dorsal view E Propodeum, dorsal view F Petiole, dorsal view G Ovipositor sheaths, lateral view H Forewing, with designated vein terminology. Abbreviations: ptl - pterostigma length, ptw - pterostigma width.