Arachnologische Mitteilungen 54

2 S. Korenko Results Host community and incidence of parasitism. The family Dictynidae consisted almost exclusively of spiders of the ge- nus Dictyna (reared adults identified as D. pusilla ); only 1 % belonged to the genus Nigma .The space web weaver D. pusilla was one of the most abundant spider species in the investiga- ted fruit orchard, representing 17.8 % of all collected spider individuals (from n = 1.069).The average incidence of parasi- tism of D. pusilla was 12 % (Tab. 1).The larvae were typically attached antero-dorsally close to the petiolus hidden between the abdomen and prosoma of the spider host. All parasitised spiders were juveniles with an average prosoma length of 0.64 mm (SD = 0.12, n = 44). Fifty-one percent of wasps rea- red in the laboratory reached the imaginal stadium. Mortality during ontogeny occured when the spider-hosts died (43 %), when the parasitoid died at the larval stage (33 %) and when the parasitoid died at the pupal stage (24 %). All parasitoid wasps reared from D. pusilla were Zatypota anomala ( n = 22). The pupal stage in laboratory rearing lasted on average 11.9 days (SD = 1.39, n = 22). During this study, Z. anomala was recorded in Italy for the first time. Reared material. Province of Cuneo: Bottonasco, organic hazel nut orchard (Cascina Rosa), larva attached to Dictyna pusilla , leg. 4.XI.2009 adult emerged 15.XII.2009–30.I.2010 (11 males, 11 females), leg. S. Korenko, det. K. Zwakhals & S. Korenko. Host parasitoid interaction. Unparasitised spiders built a ty- pical cribellate (sticky) space web with a retreat formed from an aggregation of threads (Fig. 1).There was no observed mo- dification of the spider web under the influence of the final stage parasitoid larva. Parasitized spiders took a position in- side their retreat (100 %), where the larva killed the host, spun a cocoon, and pupated (Fig. 2). Cocoons were diaphanous, white, and sub-cylindrical, with a springy and very open con- struction of sparse loose whorls. Discussion The community of arboreal spiders in the studied fruit orchard was dominated by space web building spiders, and Dictynidae represented 17.8 % of all collected spiders. Dictynid spiders were relatively frequently parasitised by polysphinctine para- sitoids (12 % average incidence of parasitism). The incidence of parasitism by polysphinctines among various spider species was mostly found to be low (often below 1–5 %) in Central Europe (Korenko et al. 2011), in Central America (Barrantes et al. 2008) and in Japan (Tanaka 2007) , but several studies from northern Italy found relatively high parasitism rates, i.e. above 10 % (Korenko et al. 2014, 2015). Zatypota anomala is known to be associated with cribellate tangle web weaving spiders belonging to the family Dictyni- dae (Aubert 1969). Vincent (1979) found this wasp to be as- sociated with Mallos pallidus (Banks, 1904) in North Ameri- ca; and the species was repeatedly reared from Dictyna sp. and D. pusilla in Europe (Miller et al. 2013, this study ). Zatypota Fig. 1: Normal web of an unparasitised spider Dictyna pusilla . Arrow shows the typical spider resting position in the centre of the tangle. Tab. 1: Relative spider host abundance (Ab.), average incidence of parasitism (PR), and wasp species documented in the studied locality (Korenko et al. 2014, Korenko et al. 2015, Korenko unpubl. data, this study). Foraging guild classification follows Cardoso et al. (2011). Host family Foraging guild n Ab. (%) PR (%) Associated parasitoids Araneidae Orb web weavers  42   3,9 11 Polysphincta tuberosa , P. boops , Zatypota picticollis , Sinarachna pallipes Tetragnathidae Orb web weavers  12   1,1  0 Dictynidae Space web weavers 190  17,8 12 Zatypota anomala Theridiidae Space web weavers 611  57,2  4 Zatypota percontatoria Linyphiidae Sheet web weavers   2   0,2  0 Mimetidae Specialists   2   0,2  0 Anyphaenidae Hunters  52   4,9  0 Clubionidae Hunters   7   0,7  0 Eutichuridae Hunters   1   0,1  0 Philodromidae Hunters 139  13,0  0 Salticidae Hunters   1   0,1  0 Thomisidae Ambush hunters  10   0,9  0 Total 1069 9 100 ,0  5