Andricus truncicolus ( Giraud, 1859 )

Andricus truncicolus ( Giraud, 1859)

Figs 1–3 View FIGURES 1–9 , 16–41 View FIGURES 16–24 View FIGURES 25–32 View FIGURES 33–41

Cynips truncicola Giraud, 1859: 345

Adleria truncicola (Giraud) : Rohwer & Fagan, 1917: 359

Andricus truncicola (Giraud) : Benson, 1953: 220

Sexual generation:

Andricus multiplicatus Giraud, 1859: 360 , syn. nov.

Type material examined - syntypes of Andricus multiplicatus ( Figs 16–24 View FIGURES 16–24 ). Giraud’s type series of A. multiplicatus in the NHMW consists of 5 syntypes, 3♀, 2♂ (both ♂ broken, only fragments present) mounted on pins or glued on cards with the following labels: 1♀ “Type” (rectangular red label, printed), “ Andricus multiplicatus Giraud ” (black label, handwritten), “Z.b. Gesellsch. Bd. IX. p. 337” (white label handwritten) [abbreviation for “Verhandlungen der Zoologisch-Botanischen Gesellschaft in Wien ” volume, IX p. 337, journal in which the species was described], “NHMW-HYM #0006912” (yellow label, printed); 1♀ with the same labels as the previous one, but “ Andricus multiplicatus Gir. det. Giraud” (white label, handwritten) and “NHMW-HYM #0006913” (yellow label, printed); 1♀ with the same labels as the previous but “NHMW-HYM #0006914” (yellow label, printed); 2♂ on the same pin, “ multiplicat. det. Giraud Type” (white label, handwritten), “ Andricus multiplicatus Giraud ” (white label handwritten).

Type locality: Austria, Giraud 1859: 337 (orig. descr.)

Additional material examined.

Specimens of Andricus multiplicatus deposited in MSNG ( Figs 25–41 View FIGURES 25–32 View FIGURES 33–41 ): 1♀, 1♂ pinned on separate micropins on the same small block of pith with the following label: “ Andricus multiplicatus Wien Giraud D. Mayr ” (white label, handwritten) “171” (small white quadrangular label, handwritten). 1♀, 1♂ pinned on separate micropins on the same small block of pith with the following label: “ Andricus multiplicatus Usciti in Luglio 1907 da galle di N. S. della Vittoria su Q. cerris Mantero ” [Emerged in July 1907 ex galls collected near the sanctuary “ Nostra Signora della Vittoria ” Genoa. Giacomo Mantero leg.] (white label, handwritten).

Specimens from galls recently collected in Austria and Hungary: 10♂: AUSTRIA: Burgerland, Hornstein from galls on Q. cerris , emerged 20. VI. 2020, Andreas Berger leg. Andricus truncicolus ( Giraud, 1859) S. Sottile det. ( GCPC & SSPC); 1♂: HUNGARY: Közseg, ex galls collected 26.VI.2010 on Q. cerris , labels HU37 and Andtru2 ( GSPC); 1♀: AUSTRIA: Unterlois, ex galls collected 5.VI.2006 on Q. cerris , labels CEH12153 and Andtru3 ( GSPC); 4♀: HUNGARY: Közseg, ex galls collected 26.VI.2010 on Q. cerris , labels HU41 and either Andtru5, Andtru6 or Andtru7 ( GSPC); 1♀: HUNGARY: Varpolata, ex galls collected 6.VI.2006 on Q. cerris , labels CEH13525 and Andtru8 ( GSPC); 1♂: HUNGARY: Matrafured, ex galls collected 8.VI.2006 on Q. cerris , labels CEH15976 and Andtru9 ( GSPC). Six of these recently collected individuals were also used for DNA sequencing.

Sexual generation specimens of Andricus truncicolus discovered through laboratory experiments and described by Sottile et al. (2023): 8♀: ITALY: Lombardy, Cinisello Balsamo ( MI), ex galls of A. truncicolus (sex) in contact chamber on Quercus cerris (labelled as “Cerro A”), emerged 8–15.VI.2022 (samples N.4521–N.4522), S. Sottile leg. ( GCPC), one also used for DNA work; 40♀: with the same label, emerged 8–15.VI.2022, but ( SSPC); 4♀ with the same label, deposited ( NHML); 30♀: with the same label, emerged 8–15.VI.2022, but ( MCLSS); 4♀: with the same label, emerged 8–15.VI.2022, but ( MCSN). 6♂: ITALY: Lombardy, Gessate ( MI), ex galls of A. truncicolus (sex) in contact chamber on Quercus cerris (labelled as “Cerro Fiorio”), emerged 6–13.VI.2022 (samples N.4568–N.4539), S. Sottile leg. ( GCPC); 18♂: with the same label, emerged 6–13.VI.2022, but ( SSPC & MCLSS); 2♂: with the same label, emerged 6–13.VI.2022, but ( MCSN); 10♂: ITALY: Lombardy, Gessate ( MI), ex galls of A. truncicolus (sex) in contact chamber on Quercus cerris (labelled as “Cerro Fiorio”), emerged 10–15.VI.2023 (samples N.4899– N.4902), S. Sottile leg. ( SSPC); 3♂ with same label but deposited ( NHML).

Molecular results. All individuals identified as A. truncicolus clustered together within the host-alternating Andricus phylogeny, and as a sister group to the very similar Middle Eastern species A. megatruncicolus Melika, 2008 ( Fig. 42 View FIGURE 42 ); asexual individuals had been identified based on their distinctive gall morphology, sexual individuals ( A. multiplicatus ) were identified through comparison of adult morphology with type material. Cytb sequences between asexual and sexual generation individuals differed on average by 0.52% (range 0.23–1.01%), a comparable level of divergence to that expected within a Cynipini species (see Nicholls et al. 2022) and similar to that observed among individuals within a single generation of this species (0–0.69%). ITS2 sequences among A. truncicolus individuals of either generation also clustered together (with one asexual individual having an identical sequence to one sexual individual); the only differences were in the number of repeated bases at two mononucleotide repeats, which again is a pattern expected for within-species variation ( Fig. 43 View FIGURE 43 ).

Nomenclatural considerations for species synonymy. Giraud (1859) described both Cynips truncicola and Andricus multiplicatus in the same work (at pages 345 and 360, respectively). Cynips truncicola was then transferred by Rohwer and Fagan (1917) to Adleria , a genus subsequently synonymised with Andricus ( Benson (1953). According to the International Code of Zoological Nomenclature ( ICZN 1999), the priority in these cases is determined by the action of the First Reviewer (Art. 24.2). Since there is no apparent reason why one of the two names should better ensure the stability and universality of the nomenclature than the other, according to the Code (Recommendation 24A), we assign priority to Andricus truncicolus ( Giraud, 1859) and consequently Andricus multiplicatus Giraud, 1859 becomes its new synonym. Our justification to assign priority to A. truncicolus is because the agamic generation gall of this species is easily distinguishable from the agamic galls of other species in the same species group, including A. conificus , while the sexual generation galls induced by many of these taxa are almost indistinguishable ( Sottile et al. 2022).

Distribution. Andricus truncicolus is a species of wide distribution in the central and eastern regions of the Western Palaearctic: Austria ( Dalla Torre &Kieffer, 1910), Montenegro ( Dalla Torre &Kieffer 1910), Czech Republic ( Kierych 1979), Bulgaria (Vassileva-Smnalieva 1974, 1985, 1991), Hungary ( Ambrus 1974; Melika 2006), Ukraine only from the Transcarpathian Region ( Csóka & Melika 1993; Melika 2006), Romania ( Ionescu 1973), Albania ( Melika 2006), Poland ( Kierych 1979), Greece ( Melika 2006), Serbia ( Marković 2014; 2022), Croatia ( Kwast 2012) including Cres-Lošinj Archipelago ( Tomasi 2019), Slovakian Republic ( Kierych 1979), Israel ( Melika 2006; Sharchar et al. 2018), Syria ( Melika 2006), Türkiye ( Dalla Torre & Kieffer 1910; Melika 2006; KatılmıŞ & Kıyak 2008). Within Italy, it is known from the northern and southern regions, including Sicily ( De Stefani 1889; 1894; Dalla Torre & Kieffer 1910; Cerasa et al. 2016; Cerasa & Lo Verde, 2021; Massa et al. 2021; Sottile et al. 2023).

Records from the Slovakian Republic, Israel and Syria ( Kierych 1979; Melika 2006; Sharchar et al. 2018) should be considered doubtful, and must be reconfirmed on the basis of adults because they refer only to the sexual generation of A. truncicolus (= A. multiplicatus ) which may have been confused with A. pseudomultiplicatus sp. nov.; also the data from Türkiye should be reconfirmed with adults because the asexual generation gall of A. truncicolus is similar to A. megatruncicolus ( Tavakoli et al. 2008; Sottile et al. 2023) and when the galls are the same size it is impossible to distinguish these species on the basis of the gall alone.