jear2012 [Journal of Entomological and Acarological Research 2013; 45:e21] [page 117] First record of Gonatocerus litoralis (Haliday) (Hymenoptera: Mymaridae) from Anoplotettix putoni Ribaut (Hemiptera: Cicadellidae) G. Viggiani Laboratorio di Entomologia - Dipartimento di Agraria, Università degli Studi di Napoli Federico II, Portici (NA), Italy Abstract The mymarid Gonatocerus litoralis (Haliday) is recorded for the first time as an egg parasitoid of the leafhopper Anoplotettix putoni Ribaut. A study of the main morphological characters shows unusual variation in distribution of the multiporous plate sensilla on the antenna and relative length of the ovipositor. The parasitoid overwinters as an immature with- in the host egg and the adult emerges from late April to early July, which coincides with oviposition by the leafhopper into grapevine bark. Introduction During studies of the leafhopper Anoplotettix putoni Ribaut (Hemiptera: Cicadellidae) in vineyards of southern Italy (Di Luca & Viggiani, 2007; Viggiani & Rillo, 2007) an egg parasitoid was found. It was identified initially as belonging to the litoralis group of Gonatocerus (Hymenoptera: Mymaridae) (Viggiani et al., 2008). The genus Gonatocerus Nees includes 287 species worldwide (Noyes, 2013), classified in several subgenera and species-groups. Gonatocerus litoralis (Haliday) is widely distributed in all biogeo- graphical regions and belongs to the subgenus Lymaenon Walker (Triapitsyn et al., 2010; Triapitsyn, 2013). The species has been redescribed several times (Debauche, 1948; Matthews, 1986; Baquero & Jordana, 2002; Triapitsyn et al., 2010; Triapitsyn, 2013), but remains difficult to define because of substantial morphological variability. To date, this variability of G. litoralis has been evaluated using only spec- imens collected by sweeping or by trapping. Triapitsyn (2013) reported the species in several locations in Italy (Campania, Lazio, Molise and Sicily). In spite of its abundance and very wide distribution, the biology of G. litoralis still remains poorly known. Known hosts are eggs of Cicadula sexnotata (Fallén), Acocephalus sp. (Matthews, 1986), Neoaliturus (Circulifer) tenellus (Baker) (Bayoun et al., 2008; Triapitsyn, 2013) and Zyginidia sohrab Zachvatkin (Hemiptera, Cicadellidae) (Fallahzadeh & Huber, 2011). In the present paper the morphological variability of G. litoralis, reared from eggs of a single host (A. putoni), is analyzed and the life cycle of the parasitoid is outlined. Materials and methods Pieces of vine bark were randomly collected in some vineyards of the Campania and Basilicata regions of Italy (Taurasi, BN; Rivello, PZ), mostly during winter and spring 2005-2006 (Viggiani et al., 2008). Eggs of A. putoni were placed singly in small vials and maintained at room temperature (18-25°C). Twenty-two Gonatocerus specimens, all females, emerged from these eggs and were dissected and mounted on slides in Canada-phenol balsam. Specimens were measured by using a Zeiss Axiophot microscope. Specimens are deposited in the collection of the entomological collection of Dipartimento di Agraria, Università degli Studi di Napoli Federico II. Results and discussion Gonatocerus litoralis (Haliday) Measurements of the main morphological characters of the reared specimens are presented in Tables 1 and 2. Those concerning the antennal segments (Figure 1A and Table 1), forewing, mesotibia and ovipositor (Table 2), may be compared in detail with the data reported by Baquero & Jordana (2002). Except for the scape, all other antennal segments are relatively longer in our specimens. Baquero & Jordana (2002) give the following distribution of multiporous plate sensilla (mps) on the funicular segments: F5 (1), F7 (1 or 2), F8 (2). In con- trast, the results here (Table 3) show that the presence of mps on F5 is rare (9%) (Figure 1D), but on F6 1or 2 mps are present rather fre- Correspondence: Gennaro Viggiani, Laboratorio di Entomologia - Dipartimento di Agraria, Università degli Studi di Napoli Federico II, via Università 133, 80055 Portici (NA), Italy. Tel.: +39.081.2539003 - Fax: +39.081.7755872. E-mail: genviggi@unina.it Key words: parasitoid, variability, leafhopper, egg, grapevine. Acknowledgments: the author is grateful to John Noyes, Natural History Museum, London, for the improvements made to the paper. Received for publication: 5 June 2013. Revision received: 6 September 2013. Accepted for publication: 24 September 2013. ©Copyright G. Viggiani, 2013 Licensee PAGEPress, Italy Journal of Entomological and Acarological Research 2013; 45:e21 doi:10.4081/jear.2013.e21 This article is distributed under the terms of the Creative Commons Attribution Noncommercial License (by-nc 3.0) which permits any noncom- mercial use, distribution, and reproduction in any medium, provided the orig- inal author(s) and source are credited. Journal of Entomological and Acarological Research 2012; volume 44:eJournal of Entomological and Acarological Research 2013; volume 45:e21 No n c om me rci al us e o nly [page 118] [Journal of Entomological and Acarological Research 2013; 45:e21] Article Figure 1. Female antenna of G. litoralis. A) Antenna from distal end of scape to clava. B) Antenna without multiporous plate sensilla on F5 and F6. C) Antenna with multiporous plate sensilla on F6 and not on F5. D) Antenna with multiporous plate sensilla on F5 and not on F6. Table 1. Measurements (mm) of the female antenna segments. Antenna Length Width Ratio L/W min.-max. min.-max. min.-max. (AV± SD) (AV±SD) (AV±SD) Radicle 0.060-0.110 0.015-0.022 3.25-5.6 0.087±0.0197 0.020±0.0014 4.383±0.8977 Scape 0.125-0.175 0.035-0.050 3.11-3.66 0.148±0.0177 0.044±0.0051 3.333±0.2285 Pedicel 0.040-0.065 0.020-0.045 1.33-2.00 0.058±0.0053 0.039±0.0049 1.508±0.1477 F1 0.030-0.045 0.017-0.025 0.8-2.25 0.038±0.0050 0.022±0.0026 1.730±0.3058 F2 0.025-0.045 0.015-0.027 1.25-2.33 0.036±0.0066 0.022±0.0030 1.645±0.2969 F3 0.030-0.055 0.020-0.027 1.55-2.00 0.040±0.0079 0.023±0.0024 1.728±0.1834 F4 0.040-0.060 0.020-0.035 1.66-2.25 0.044±0.0055 0.024±0.0035 1.944±0.1469 F5 0.045-0.065 0.020-0.035 1.71-2.75 0.054±0.0047 0.027±0.0043 2.074±0.2842 F6 0.045-0.065 0.025-0.037 1.63-2.16 0.056±0.0072 0.031±0.0040 1.825±0.1465 F7 0.045-0.065 0.025-0.040 1.5-2.00 0.058±0.0054 0.033±0.0055 1.755±0.1551 F8 0.040-0.065 0.030-0.050 1.2-1.85 0.055±0.0070 0.040±0.0051 1.382±0.1607 Clava 0.160-0.215 0.050-0.070 2.66-3.72 0.187±0.0180 0.060±0.0071 3.100±0.2651 AV, average; SD, standard deviation; Ratio L/W, ratio length/width; F, funicular segment. No n c om me rci al us e o nly quently (59%) (Figure 1C). Several specimens (37%) (Figure 1B) show any mps on F5 and F6. The ratio L/W of the forewing is similar, but the ratio MFL/FWW is markedly different, as is the ratio OVL/MTL. The measurements and ranges of variation presented here fall with- in the broad concept of G. litoralis given by Triapitsyn et al. (2010) and Triapitsyn (2013). However, without additional evidence from more material reared from known hosts, combined with an analysis of molec- ular data, it is difficult to determine whether Triapitsyn’s (2013) con- cept represents a species complex or a single variable species. Biology In southern Italy, A. putoni overwinters as an egg inserted into the rough bark of the grapevine. Eggs hatch in March and April and the nymphs migrate to wild and cultivated plants (mainly Fabaceae), where they feed and develop. Adults appear in late May; their popula- tion increases during June and July and then progressively declines. There is one generation per year, similar to the allied species A. fus- covenosus (Ferrari), a possible host of G. litoralis, distributed in cen- tral and northern Italy (Alma, 1995). G.litoralis overwinters as an immature in the host eggs and the adults emerge from late April to early July. The life cycle of the parasitoid seems to be synchronized with that of the host. As with other parasitoids associated with grapevine bark, it is likely that G. litoralis can also develop in the egg of Scaphoideus titanus (Ball) (Arzone & Alma, 1994). References ALMA R., 1995 - Ricerche bio-etologiche su Anoplotettix fuscovenosus (Ferrari) (Cicadellidae Deltocephalinae). - Boll. Zool. Ge. Bach. Milano Ser. II 1: 45-52. ARZONE A., ALMA A., 1994 - Indagini sui parassitoidi oofagi di Scaphoideus titanus Ball (Auchenorrhyncha Cicadellidae). - MAF - Convegno “Lotta biologica”, Acireale: 83-88. BAQUERO E., JORDANA R., 2002 - The genus Gonatocerus Nees (Hymenoptera Chalcidoidea Mymaridae) in corn fields of Navarra, North Spain. - Redia 85: 1-19. BAYOUN I.M., WALKER G.P., TRIAPITSYN S.V., 2008 - Parasitization of beet leafhopper eggs, Circulifer tenellus, in California. - J. Appl. Entomol. 132: 412-424. DEBAUCHE H.R., 1948 - Étude sur les Mymarommidae et les Mymaridae de la Belgique (Hymenoptera-Chalcidoidea). - Mem. Mus. His. Nat. Belg. 108: 1-248. DI LUCA A., VIGGIANI G., 2007 - Indagine su Anoplotettix (Homoptera: Cicadellidae) in vigneti campani.- Proc. XXI Congr. Naz. Ital. Ent., Campobasso: 191. FALLAHZADEH M., HUBER J. T., 2011 - The occurrence of Gonatocerus litoralis (Haliday, 1833) (Chalcidoidea, Mymaridae) in Iran, with a new host record. - Munis Entomol. Zool. 6: 297-300. MATTHEWS M. J., 1986 - The British species of Gonatocerus Nees (Hymenoptera: Mymaridae), egg parasitoids of Homoptera. - Syst. Entomol. 11: 213-229. NOYES J.S., 2013 - Universal Chalcidoidea database. - Available from: http://www.nhm.ac.uk/entomology/chalcidoids/index.html TRIAPITSYN S., 2013 - Review of Gonatocerus (Hymenoptera: Mymaridae) in the Palaearctic region, with notes on extralimital distributions. - Zootaxa 3644: 1-178. TRIAPITSYN S.V., HUBER J.T., LOGARZO G.A., BEREZOVSKIY V.V., AQUINO D.A., 2010 - Review of Gonatocerus (Hymenoptera: Mymaridae) in the Neotropical region, with description of eleven new species. - Zootaxa 2456: 1-243. VIGGIANI G., DI LUCA A., RILLO L., 2008 - Ulteriori dati sull’Anoplotettix putoni Ribaut (Homoptera: Cicadellidae) e i suoi ooparassitoidi in Campania. - Boll. Lab. Ent. Agr. Filippo Silvestri 62: 11-17. VIGGIANI G., RILLO L., 2007 - Cicaline del vigneto e loro ooparassitoi- di: nota preliminare su Anoplotettix spp. (Homoptera: Cicadellidae). - Atti I Conv. Naz. Viticoltura - Parte I, Ancona, 21-23 giugno 2006. - Italus Hortus 14: 230-231. [Journal of Entomological and Acarological Research 2013; 45:e21] [page 119] Article Table 2. Measurements (mm) of the forewing, mesotibia and ovipositor. Min.-max. AV±SD FWL 0.920-1.080 1.013±0.0490 FWW 0.250-0.350 0.314±0.0263 L/W 2.94-3.68 3.23±0.187 MFL 0.050-0.100 0.070±0.0104 MLF/FWW 3.40-5.83 4.51±0.523 MTL 0.250-0.320 0.289±0.0173 OVL 0.480-0.550 0.519±0.0171 OVL/MTL 1.56-2.03 1.79±0.107 AV, average; SD, standard deviation; FWL, forewing length; FWW, forewing width; L/W, ratio forewing length/forewing width; MFL, maximum fringe length; MFL/FWW, ratio maximum fringe length/maximum forewing width; MTL, mesotibia length; OVL, ovipositor length; OVL/MTL, ratio ovipositor length/mesotibia length. Table 3. Distribution of multiporous plate sensilla on the female antenna segments. Sp. F5 F6 F7 F8 Clava 1 0 0 2 2 10 2 0 1 2 2 10 3 0 0 1 1 10 4 0 1 1 2 10 5 0 1 0 2 10 6 0 0 2 2 10 7 0 1 1 2 10 8 1 1 1 2 10 9 0 0 1 2 10 10 0 1 1 2 10 11 0 1 1 2 10 12 0 0 1 1 10 13 0 1 1 2 10 14 0 1 1 2 10 15 0 0 1 2 10 16 0 1 1 2 10 17 0 0 2 3 10 18 0 2 2 3 10 19 1 0 2 2 10 20 0 0 1 2 10 21 0 2 2 2 10 22 0 2 2 2 10 Sp., specimen; F, funicular segment. No n c om me rci al us e o nly