Sigara iactans (Jansson 1893)
This is a recent arrival to Britain first being discovered in a Norfolk sandpit March 2005 by Sheila Brooke and Bernard Nau (Brooke.S. Het News Spring 2005) and since then it has been spreading across the eastern counties and older records are being verified and found.
This is a Ponto-Menditerranean species established in Greece, Macedonia, Romania, Russia Turkey and Ukraine and spreading Northwards through Begium, Denmark, Germany, France, Poland, Sweden, Netherlands and England.
From Europe it has been noted from nutrient-poor, sparsely vegetated waters, partially with low pH; also as a pioneer species in newly- created reservoirs. In the Netherlands, most waters where S. iactans is found have little submerged vegetation and the acidity (pH) is generally alkaline (>7), the species avoids acid waters; inhabited waters are always permanent and usually quite large (eutrophic watercourses, mesothrophic sandpits); slow current is tolerated, but the species was only infrequently found in brooks. Strikingly often it is found in fresh and slightly brackish dune lakes on the West Frisian Islands. (PKM, 2013)
Emergence period:
GB IUCN Status: Least Concern
Northants status: Local Species of Conservation concern - Increasing
Number of records: 4
Number of sites: 3
1km squares recorded: 3
5km squares recorded: 3
10km squares recorded: 3
Nb. Another 2 records has been found at Islip bridge in 2019 and 2023 but not the map hasnt been updated yet.
Distribution:
There are just 4 records in Northants making this a scarce bug. The first was from the River Welland at Sibbertoft in 2007 close to the border with Leicestershire. Two were in 2019 and 2023 from the River Nene at 9 Arches bridge on the River Nene. The third was in 2022 at the County Golf Course, Chapel Brampton in a small reservoir that had very little vegetation. With detailed identification of all Sigara falleni males then we should turn up more sites across the county.
Habitat:
This is found in a range of habitats similar to that of Sigara falleni with a preference for sparsley vegetated sites with little organic matter.
Identification:
This is very similar to S. falleni in both have 7 or more pale lines on the pronotum and a pointed margin to the pronotum. The best way to identify is explained in (J, 1983) to compare the male palae of the two species and S.iactans is more rounded and the bottom row of pegs points at the front of the upper row. Females are more tricky but with care there is a feature in (J, 1986) where the female middle leg claw is shorter than the postnatal pruinose area of the forewing where S.falleni is slightly longer
