Arachnologische Mitteilungen 54

Arachnologische Mitteilungen / Arachnology Letters 54: 1-4 Karlsruhe, September 2017 With 50 described species, the genus Zatypota comprises highly specialised koinobiont ecto-parasitoids of spiders and is the largest genus of the Polysphincta -group in the world (Gauld & Dubois 2006, Matsumoto & Takasuka 2010, Yu et al. 2012, Fritzén 2014). Zatypota probably includes as many species as in all other genera of the Polysphincta genus- group combined, and many undescribed species still exist in museum collections (e.g. Gauld & Dubois 2006). All Zaty- pota species are narrowly associated with a specific host spi- der species or a small group of closely related spider species. Zatypota wasps are mostly parasitoids of theridiid spiders (Nielsen 1923, Fitton et al. 1988, Gauld & Dubois 2006, Korenko & Pekár 2011, Korenko et al. 2011), but three Za- typota species are associated with spiders other than theri- diids (Matsumoto & Takasuka 2010, Korenko et al. 2015, Vincent 1979). Eight species from the genus Zatypota occur in Europe (de Jong et al. 2014, Fritzén 2010, 2014). Six of them – Zatypota percontatoria (Müller, 1776) , Z. bohemani (Holmgren, 1860) , Z. discolor (Holmgren, 1860), Z. kerstinae Fritzén, 2010 , Z. albicoxa (Walker, 1874) and Z. flamma Fritzén, 2014) – are strictly associated with tangle web weavers from the family Theridiidae. Zatypota percontatoria, Z. bohemani, Z. discolor and Z. kerstinae are associated with spiders from the genus Theridion , or closely-related genera (e.g. Phylloneta , Neottiura ) with similar habitus and behaviour (Fitton et al. 1987, 1988, Korenko et al. 2011, Korenko & Pekár 2011, Fritzén 2010, 2014). By contrast, Z. albicoxa and Z. flamma are associated with the genus Parasteatoda (e.g. Fitton et al. 1987, 1988, Fritzén 2014). Zatypota picticollis (Thomson, 1888) is associa- ted with orb web weavers from the family Araneidae (Zwak- hals 2006, Korenko et al. 2015), while the species studied here, Zatypota anomala (Holmgren, 1860), which is distribu- ted across the Holarctic, is known to be associated with space web weavers from the family Dictynidae (Vincent 1979, Yu et al. 2012). The aim of this study was to analyse Z. anomala popula­ tions in the canopies of an ecological fruit orchard in nort- hern Italy and to observe the interaction between the parasi- toid larva and its spider host in the laboratory. Material and methods Web building spiders (Araneae, Orbicularia) and their ecto- parasitoids (Hymenoptera, Ichneumonidae, Polysphincta ge- nus group) were collected from tree canopies (between 40 cm and 200 cm above ground) in an organic hazelnut orchard in Bottonasco (44°25’13.9”N 7°23’40.2”E, 642 m a.s.l.) in the province of Cuneo (Piedmonte region, northern Italy) on the 4th November 2009. Spider hosts and parasitoids at the larval stage attached to them were collected by beating tree branches and catching the spiders in a square shaped beating net (1 m 2 area) placed beneath the tree crown.Three samples (each sample was coll- ected by beating 30 trees) were taken and preserved in 70 % alcohol. The collected spiders were identified to genus level using Nentwig et al. (2017) and matched to species both on the basis of formerly known occurring species in the investi- gated localities (Isaia et al. 2010, Korenko unpubl. data) and by rearing the collected specimens to adulthood. Live unparasitised and parasitized spiders were collected by the same method (described above) and reared in the la- boratory. Parasitoid larvae were reared to imagines. Hatched wasps were identified using Fitton et al. (1988) and Zwak- hals (2006). The nomenclature of the wasps follows Yu et al. (2012). Voucher specimens were deposited in the collec- tion of the author and in the collection of Kees Zwakhals (Netherlands). The web architecture of non-parasitised (n = 12) and pa- rasitised (n = 44) spiders was studied by placing spiders indi- vidually in square glass experimental arenas (100 × 100 mm base, 130 mm height) with an installed tree twig that pro- vided three-dimensional space for the spider’s webbing. Spiders were kept at room temperature (22 ± 3 °C) under a natural L:D regime and fed with a surplus of Drosophila flies. The webs of both unparasitised and parasitised spiders were recorded using a Canon EOS 500D digital camera with an EF-S 18–55 mm lens or a macro EF 100 mm f/2,8L IS USM lens. First record from Italy of Zatypota anomala (Ichneumonidae, Ephialtini), a parasitoid of the cribellate spider Dictyna pusilla (Araneae, Dictynidae) Stanislav Korenko doi: 10.5431/aramit5401 Abstract. The polysphinctine wasp Zatypota anomala (Holmgren, 1860), a koinobiont ecto-parasitoid of spiders in the family Dictynidae, was recorded in Italy for the first time. Populations of both the wasp and its host, Dictyna pusilla Thorell, 1856, its host preference and the interaction between the parasitoid and the spider were documented in the field and by laboratory observations. Keywords: ectoparasitoid, host parasitoid interaction, host range, host specialisation, spider web Zusammenfassung. Erstnachweis von Zatypota anomala (Ichneumonidae, Ephialtini) für Italien, ein Parasitoid der cribellaten Spinne Dictyna pusilla (Araneae, Dictynidae). Die zu den Polysphinctinae gehörende Schlupfwespe Zatypota anomala (Holmgren, 1860), ein koinobionter Extoparasit von Spinnen der Familie Dictynidae, wurde erstmals für Italien nachgewiesen. Es werden Populatio- nen der Wespe und ihres Wirtes, Dictyna pusilla Thorell, 1856, die Wirtspräferenz und Interaktionen zwischen Parasitoid und Spinne aus dem Freiland und dem Labor dokumentiert. Stanislav Korenko , Department of Agroecology and Biometeorology, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Suchdol, Czech Republic; E-mail: korenko.stanislav@gmail.com submitted 17.2.2017, accepted 18.4.2017, online 30.4.2017