236 Euura abnormis (Holmgren, 1883)

Figs 255, 494

Nematus abnormis Holmgren, 1883: 148, pl. 3 fig. 16. Syntypes ♀♀ (NHRS), not examined. Type locality: Russia, Novaja Zemlya, Besimannija Bay.

Amauronematus glacialis Jakowlew, 1891: 26–27 . Syn. nov.

Amauronematus tolli Konow, 1907: 20–21, 24, pl. Lectotype designated by Muche (1975). Synonymy by Benson (1960).

Amauronematus aulatus MacGillivray, 1919: 16–17 . Synonymy by Benson (1962).

Diagnosis

Mostly black abdomen, black metafemur and often also black metatibia (sometimes the body is nearly completely black) distinguish the females from the others in the group. Females are sometimes shortwinged. Males are nearly completely black, apex of pseudoceps of the penis valve has a long spine or filament that is strongly curved dorsally, and a valvispina is missing. The pseudoceps of three other species of Euura has a long spine or filament-like extension. In E. longicauda the extension is also curved dorsally, but it is thinner and a valvispina is present. In E. cornuta ( E. viduata group) and E. amentorum ( E. amentorum group) the extension of the pseudoceps is more or less straight.

Type material examined

Holotype Amauronematus glacialis

RUSSIA • ♀; Novaja Zemlya; Grinewetski leg.; ZIN, DEI-GISHym30222.

Lectotype Amauronematus tolli

RUSSIA • ♀; Siber. bor. or. [north-east Siberia: around mouth of the River Lena, and from the New Siberian Islands]; SDEI, GBIF-GISHym4085.

Holotype Amauronematus aulatus

USA – Alaska • ♀; Barter Island; 70.121° N, 143.663° W; 16 Jun. 1914; D. Jenness leg.; CNC, CNC957884.

Host plants

Salix herbacea, S. polaris . Oviposition is into the leaf blade, where a conspicuous procecidium develops on the upper side. The young larva at first feeds inside this, but later leaves and feeds from the leaf edge. Interestingly, sequencing of gut contents of one swept larva (DEI-GISHym80086) suggested that it had been feeding on Bistorta sp. (presumably B. vivipara). In addition, we noticed that numerous young larvae (together with E. obscuripes) originally collected from Salix herbacea fed readily on other willows (e.g., S. phylicifolia) and even B. vivipara after the S. herbacea had been consumed. Because of the small size of the dwarf willows, the externally-feeding larvae on these plants generally need to move around to find sufficient food, and acceptance of other plant species nearby may be an adaptation that helps them to cope with this.

Genetics

COI

Based on 10 specimens, maximum within-species distance is 0.76% and the nearest neighbour, diverging by a minimum of 0.76%, is Euura longicauda .

Nuclear

Based on 8 specimens, maximum within-species distance is 0.79% (0.71% based on haplotypes of individual females). The nearest neighbour, diverging by a minimum of 0.89%, is Euura neglecta .

Distribution and material examined

Holarctic. Specimens studied are from Finland, Norway, Russia, Sweden, United Kingdom, and the USA.