Platynothrus troendelagicus A. & S. Seniczak, 2022

Adult: The length of the body is 663–722 µm, and the width is 377–436 µm. The color is dark brown. The bothridial seta is medium sized, bacilliform, with a thickened and barbed head (Figs. 1 and 2). The notogaster has three pairs of longitudinal ridges and 15 pairs of medium sized setae, with the notogastral seta f₂ being longer than seta e₂ (Fig. 1). The adult has one pair of hyposthomal setae m (Fig. 3) and a palp femur with one seta (Fig. 4). Three pairs of adanal setae and two pairs of anal setae are present. The leg tarsi have one claw (Seniczak et al. 2022b).

Juvenile stages: Larva: body length 314 µm, width 139 µm. Protonymph: body length 400 µm, width 185 µm. Deutonymph: body length 494 µm, width 225 µm. Tritonymph: body length 578 µm, width 286 µm. The color is whitish, however the prodorsum, the epimeres and the legs are light brown. The prodorsum is subtriangular, with the central part punctate and with small pits (Figs. 5 and 6). All juveniles have one pair of hyposthomal setae m, and a palp femur with one seta, similar to the adults (Seniczak et al. 2022b).

The reproduction is parthenogenetic (Seniczak et al. 2022b), that is, only females are present and they are produced from unfertilized eggs.

Distribution

Platynothrus troendelagicus was first found in bogs in Norway. It also occurs in the peatlands in Ireland and Canada (Seniczak et al. 2022b).

Habitat

The species is known from peatlands, where it prefers moist habitats, like lawns and carpets (Seniczak et al. 2022b).

Findings in Norway

Platynothrus troendelagicus was first found in two Atlantic Raised Bogs, at Hitra and Høstadmyra in Trondheim, both in Trøndelag, Central Norway (Seniczak et al. 2022b). It was later also found in Atlantic Raised Bogs in Western and Northern Norway (A. Seniczak, pers. comm. 2023).