NEW RECORDS OF THE GENUS PSILONOTUS WALKER (HYMENOPTERA: PTEROMALIDAE) IN THE CARPATHIAN BASIN

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1 Analele Științifice ale Universității Al. I. Cuza Iași, s. Biologie animală, Tom LV, 2009 NEW RECORDS OF THE GENUS PSILONOTUS WALKER (HYMENOPTERA: PTEROMALIDAE) IN THE CARPATHIAN BASIN Mircea-Dan MITROIU Al. I. Cuza University, Faculty of Biology, Bd. Carol I 20A, Iasi, Romania, mircea.mitroiu@uaic.ro Abstract. The genus Psilonotus Walker is recorded for the first time in Romania and Hungary. P. adamas Walker is recorded from Romania and Hungary, while P. achaeus Walker and P. hortensia Walker are recorded from Hungary. P. adamas is redescribed and illustrated. Three new parasitoid-plant associations are also mentioned: P. adamas with Betula pendula and B. pubescens, and P. hortensia with B. pubescens. Key words: Hymenoptera, Chalcidoidea, Pteromalidae, Psilonotus, Carpathian Basin, Romania, Hungary. Rezumat. Noi menționări ale genului Psilonotus Walker (Hymenoptera: Pteromalidae) în Bazinul Carpatic. Genul Psilonotus Walker este menționat pentru prima datǎ în România și Ungaria. P. adamas Walker este menționat din România și Ungaria, în timp ce P. achaeus Walker și P. hortensia Walker sunt menționate din Ungaria. Specia P. adamas este redescrisă și ilustrată. Sunt menționate de asemenea trei relații parazitoid-plantă noi: P. adamas cu Betula pendula și B. pubescens, și P. hortensia cu B. pubescens. Cuvinte cheie: Hymenoptera, Chalcidoidea, Pteromalidae, Psilonotus, Bazinul Carpatic, România, Ungaria. Introduction The genus Psilonotus Walker belongs to the subfamily Pteromalinae, the largest subfamily in Pteromalidae and most poorly understood from taxonomical point of view. The genus Janvartsovia Nikol skaya, 1954 was synonymized with Psilonotus Walker, 1834 by Graham (1958). Graham (1969) provides a key to the three known species of Psilonotus: P. adamas Walker, 1834, P. achaeus Walker, 1848 and P. hortensia Walker, 1846 and synonymies his P. alticornis Graham, 1957 with P. hortensia. All Psilonotus species are known as primary parasitoids of Semudobia belulae (Winnertz) (Diptera: Cecidomyiidae) developing in seeds of Betula spp. (Noyes, 2003). Material and methods The examined material is deposited in the Hungarian Natural History Museum (HNHM), Budapest and the Mitroiu Collection (MICO), Faculty of Biology, Alexandru Ioan Cuza University, Iasi, Romania. The illustrations were made using a camera lucida attached to a microscope and a digital camera attached to a stereomicroscope. Terminology follows Bouček (1988). A list of synonyms for each species can be found in Graham (1969) and Noyes (2003). Results Psilonotus Walker, 1834 Psilonotus Walker, 1834; type species: P. adamas Walker, by monotypy. Brief diagnosis: Antenna (Fig. 4); clypeal margin medially incised (Fig. 2); thorax more or less flattened (Fig. 1), scutellum with obliterated reticulation; female gaster compressed laterally, hypopygium reaching at least 3/4 the length of gaster (Fig. 1). -85-

2 Mircea-Dan Mitroiu Psilonotus achaeus Walker, 1848 Psilonotus achaeus Walker; Walker, F., List of the specimens of Hymenopterous insects in the collection of the British Museum, part 2, pp. 105, 161. E. Newman, London. Diagnosis: The species can be recognized by a very short pronotal collar and the antennae with the lower edge of the toruli situated at or slightly below the level of the ventral edge of the eyes (cf. Fig. 2). Material examined: 2 and 2 mounted on the same card, together with a Betula catkin: [Hungary], Budapest, 1940, Ex. Semudobia betulae, leg. G. Balàs, Psilonotus hortensia Wlk., det. Szelényi, Distribution: Holarctic region: Canada, Czech Republic, Germany, Kazakhstan, Netherlands, Sweden, Turkey, Ukraine, U.K., U.S.A (Noyes, 2003); previously unrecorded from Hungary. Biology: The species was recorded by different authors as a parasitoid of Semudobia betulae on Betula sp. and B. papyrifera; also associated with Arctium lappa (Noyes, 2003). Psilonotus adamas Walker, 1834 (Figs. 1-5) Psilonotus adamas Walker; Walker, F., Monographia Chalciditum. (Continued). Entomological Magazine 2(2): 179. Diagnosis: The species can be recognized by the long pronotal collar (Fig. 3) and the antennae with the lower edge of the toruli situated slightly below the level of the ventral edge of the eyes (Fig. 2). Description. Female: Head and thorax bright green, gaster darker, with cupreous reflections; scape and pedicellus reddish-brown, funicle brown; mandibles yellowishbrown; coxae as thorax, femora mostly dark, trochanters, tibiae and tarsi brownish-yellow, with the last tarsal segment brown; wings hyaline, tegulae yellowish-brown, venation brown. Body length: mm. Head width X length in dorsal view, about as wide as thorax. Frons flattened. Temples strongly convergent, 1/3 the eye length or slightly less. POL X as long as OOL. Eye height about X length, separated by X their length. Malar space about 0.7X as long as eye length and about half as long as eye height. Oral fosa about 1.8-2X as long as malar space and almost half of head width. Clypeus deeply incised medially, apparently bidentate. Antennae inserted lower than eyes. The shortest distance between each torulus and adjacent eye margin about 1.4X as long as the distance between toruli. Scape length (without radicle) about X width, slightly shorter than eye height, not reaching the lower margin of the anterior ocellus. Combined length of pedicellus and flagellum equal or slightly less than head width. Pedicellus length about X width, about twice as long as the 3 transverse annelli together, the first two being about equal in length and the third slightly longer. Funicular segments (F) with one relatively sparse row of sensillae, slightly transverse to quadrate; F1(L:l) = 0.6-1, F5 = Clava length X width. Thorax (including propodeum) length about 1.4X width. Length of pronotal collar (medially) X its maximum width, the collar slightly longer than 1/5 the length of mesoscutum, it anterior margin slightly raised. Mesoscutum width about X length (medially), with fine, engraved sculpture. Parapsidal grooves distinct only in anterior part of mesoscutum. Scutellum flattened, situated in the same plan as propodeum, very shiny, and covered with a very fine, engraved sculpture, as long as wide or slightly wider; frenal line absent. Propodeum width about X length (medially), slightly -86-

3 Analele Științifice ale Universității Al. I. Cuza Iași, s. Biologie animală, Tom LV, 2009 more than 1/3 the length of scutellum, uniformly covered with fine, engraved sculpture. Plicae visible only in the posterior part. Nucha with two small, superficial foveae in its anterior part. Spiracles small, oval, their larger diameter smaller or equal to the distance between the anterior margin of the spiracle and the posterior margin of the metanotum. Fore wing length about X width. Basal cell, including basal vein, glabrous, the latter occasionally with one hair. Ventral side of costal cell with one uninterrupted row of hairs, only distally with two more. Speculum moderate, open below. Wing disc with relatively rare and short hairs. Marginal vein about X as long as stigmal vein and about equal to the postmarginal vein. Gaster elongated, laterally compressed, dorsally convex, length about X width, narrower than thorax and slightly to distinctly longer than head plus thorax. Basal tergite occupying less than 1/3 the length of gaster. Hypopygium reaching or almost reaching the tip of the gaster. Material examined. 3 : Romania: Hunedoara county, Retezat National Park, Retezat peak (2485m), 13.VIII.2004, leg. M.-D. Mitroiu; 1 : [Hungary], Bátorliget, dr. Erdős, Betula sp., coll. Dr. J. Erdős; 1 : [Hungary], Bátorliget, dr. Erdős, De Betula pendula L., coll. Dr. J. Erdős; 1 : [Hungary], Bátorliget, dr. Erdős, De Betula pubescens Ehrh., coll. Dr. J. Erdős; 1 : [Hungary], Tompa, Zsiroskúti erdö, 1961.VI.6, Dr. Erdős, De fronde Betula pendula Roth., coll. Dr. J. Erdős; 2 on the same card: [Hungary], Szarvas 1949, Pepikert, leg. G. Balàs, 8047, Ex. gallis Semudobiae betulae, Psilonotus hortensia Wlk., det. Dr. Szelényi, 1957; 2 on the same card, 8048: same information as 8047; 2 on the same card, 8049: same information as Distribution. Palaearctic region: Czech Republic, Germany, Kazakhstan, Netherlands, Russia, Sweden, Turkey, Ukraine, U.K. (Noyes, 2003); previously unrecorded from Romania and Hungary. Biology. Recorded by different authors as a parasitoid of Semudobia betulae on Betula sp. (Noyes, 2003); new association with B. pendula and B. pubescens. Remarks. The three females collected in Romania were swept on the plateau of the Retezat peak, which is covered with short herbaceous vegetation, consisting mainly in Poaceae. The only trees in this area are growing at a much lower altitude and are coniferous. No Betula trees could be identified in the surroundings. Thus, apparently the individuals were brought to the peak by the wind, this being a convenient way of dispersal for these tiny insects. The specimens from Romania show slight differences from those from Hungary: POL is relatively longer, the antennae are less clavate, and the funicle segments are relatively longer. Psilonotus hortensia Walker, 1846 Psilonotus hortensia Walker; Walker, F., Characters of some undescribed species of Chalcidites. Annals and Magazine of Natural History 17: 113. Diagnosis: The species can be recognized by a very short pronotal collar and the antennae with the lower edge of the toruli situated slightly above the level of the ventral edge of the eyes. Material examined. 4, two on the same pin: [Hungary], Bátorliget, dr. Erdős, De Betula pubescens Ehrh., coll. Dr. J. Erdős. Distribution. Palaearctic region: Germany, Netherlands, Sweden, Turkey, U.K. (Noyes, 2003); previously unrecorded from Hungary. Biology. Reared by Askew (1970) from birch catkins infested by Semudobia betulae; new association with B. pubescens. -87-

4 Mircea-Dan Mitroiu Figures 1-5. Psilonotus adamas Walker, : 1. Habitus, lateral view; 2. Head, frontal view; 3. Head and anterior part of the thorax, dorsal view; 4. Antenna; 5. Fore wing. -88-

5 Analele Științifice ale Universității Al. I. Cuza Iași, s. Biologie animală, Tom LV, 2009 Conclusions The genus Psilonotus Walker is recorded for the first time in Romania and Hungary. P. adamas Walker is recorded from Romania and Hungary, while P. achaeus Walker and P. hortensia Walker are recorded from Hungary. Three new plant-parasitoid associations are also recorded: P. adamas with Betula pendula and B. pubescens, and P. hortensia with B. pubescens. P. adamas was collected at an unusually high altitude (2485m), showing that this species is easily dispersed by wind. Acknowledgements. I am indebted to Dr. Zoltán László for the loan of several specimens of Psilonotus from HNHM. References Askew, R. R Observations on the hosts and host food-plants of some Pteromalidae (Hym., Chalcidoidea). Entomophaga 15(4): Bouček, Z Australasian Chalcidoidea (Hymenoptera). A biosystematic revision of genera of fourteen families, with a reclassification of species. CAB International, Wallingford, Oxon, U.K., Cambrian News Ltd; Aberystwyth, Wales, 832 pp. Graham, M. W. R. de V A revision of the Walker types of Pteromalidae (Hym., Chalcioidea). Part 3 (including descriptions of new species). Entomologist's Monthly Magazine 93: Graham, M.W.R. de V The identity of the genus Janvarstovia Nikol'skaya (Hym., Chalcidoidea, Pteromalidae). Entomologist's Monthly Magazine 94: 120. Graham, M. W. R. de V The Pteromalidae of north-western Europe (Hymenoptera: Chalcidoidea). Bulletin of the British Museum (Natural History) (Entomology) Supplement 16: pp. Noyes, J. S Universal Chalcidoidea Database. World Wide Web electronic publication. [accessed 04-Mar-2009]. -89-

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