Spilomena enslini Blüthgen,1953
Description and notes
As one of the more recently defined taxa (Blüthgen, 1953) this species has rather more taxonomic stability than other species within the genus.
Distribution
This species is restricted to southern England, with the majority of records coming from south of the River Thames between Kent and Hampshire. There are also scattered records for Devon, Berkshire, Oxfordshire and East Suffolk. Richards (1980) additionally lists Queens County (Leix), Ireland.
This species is known across northern and central Europe.
Status (in Britain only)
This species is not regarded as scarce or threatened.
Habitat
This species might be encountered wherever suitable nesting sites are available.
Flight period
Available records range mainly from May to September, with the majority coming from June, July and August.
Prey collected
In keeping with the genus as a whole, the cells are stocked with nymphs of thrips (Thysanoptera). Lomholdt (1984) notes that Frankliniella intonsa (Trybom) is one such prey species.
Nesting biology
This species appears to favour pith-filled stems of woody shrubs, such as bramble and elder. Vikberg (2000) adds raspberry and red-berried elder in Scandinavia. Despite the narrowness of these stems, Lomholdt (1984) suggests that some nests may yet be constructed with a branched pattern.
Flowers visited
No data available.
Parasites
Lomholdt (1984) lists the ichneumon wasp Neorhacodes enslini (Ruschka), the eupelmid wasp Eupelmus (as Eupelmella) vesicularis (Retzius) and the pteromalid wasps Lonchetron fennicum Graham and Kaleva livida Graham. The first three species, at least, occur in Britain. He also quotes “Leptocryptus geniculatus Thomson”, a cryptine ichneumon wasp. This is probably a misidentification of the species now known as Bathythrix fragilis (Gravenhorst) which is known to parasitise species of Rhopalum and Trypoxylon (G Broad, pers. comm.).
Year profile last updated
2016