EN
The peripheral population of N. speciosa, discovered in 2004 in the nature reserve “Broduszurki”, SE Poland (49o49’ N, 22o21 ’ E; UTM EA91), is the southernmost remain- ing population of the species in E Europe and E part of Central Europe. The Broduszurki population represents the same Evolutionary Significant Unit (ESU) as other Polish popu- lations of the species and could be included into the same Management Unit (MU). How- ever, a slightly greater genetic distance and genetic differentiation against all other stud- ied populations, combined with the current state of strong isolation (the nearest species locality 90 km distant), might justify treating this population as a separate MU. This population, occupying ca 0.06 ha, is medium-sized (max > 400 imagines per control and min 1500 in the flight period) and dynamic, re- cently increasing and colonizing new patches of the habitat, but also tightly attached to se- lected small areas. The local high density was mirrored in a high mortality in spiders’ webs (e.g. 36 individuals/14 webs or 35/15). The habitat of N. speciosa is secondary: several- dozen-year old peat excavation pools in dif- ferent stages of succession, surrounded by low peaty pine forest. N. speciosa occurred in two subpopulations (pools) and four habitat patches. It was related mostly to the rich in water habitat with Carex rostrata, Sphagnum sp., Warnstorfia fluitans, and admixtures of Juncus effusus and Molinia caerulea, resem- bling the “rostrata” habitats known from sev- eral other localities in E Poland and Europe. However, the species occurrence in one patch based mostly on Molinia caerulea is excep- tional, known only from Lower Saxony, where one locality even highly resembles the Broduszurki one. The habitat in this patch is spatially separated between the lar- val one (Warnstorfia fluitans “soup” in water) and that one for imagines - land tussocks of M. caerulea explored by the species up to 5 m from the water. Dry leaves of Molinia, hanging into water and used for the emergence were a passage between these two microhabitats. However, the use of such an untypical habitat is possible only due to a specific combination of conditions, such as the appropriate submarged vegetation (W. fluitans) and the occurrence of M. caerulea under the canopy of trees protect- ing from excessive insolation and stronger winds. As N. speciosa was not observed in other seemingly similar places nearby for no apparent reason, it seems that some of these conditions have remained unrecognised.