(089/XOarm) Xenyllodes armatus (Axelson, 1903)
Xenyllodes armatus is a small (1.0 mm) distinctive greyish blue species which is scarce in UK/Eire. It is probably widespread in Ireland but has not yet been recorded from Scotland and northern England. Most records are from wet habitats such as debris at the margins of lakes.
There are five ocelli in each eye, and a three-lobed post-antennal organ is present (Fig. 1). The empodium on the foot is either absent (Fig. 2) or extremely small. The mucro is spoon-shaped (Figs. 3, 4) and there are two small anal spines at the tip of the abdomen (Fig. 5). The antennae are conical in form (ant4 is about half the width of ant1; Fig. 6).
Fig. 1: Post-antennal organ (PAO) with three lobes (*) and ocelli (1-5) of Xenyllodes armatus collected from Kew Gardens in March 1961 September 1962 by J.L. Gilbert.
Fig. 2: Foot of the first leg of Odontella lamellifera collected from Dartmoor, Devon in June 1956 by D.F. Rumsey. The empodium is extremely small, or absent altogether as in this example.
Fig. 3: Furca of Xenyllodes armatus collected from Bantry, Co. Cork, Ireland in January 1953 by T. Clay. Ant, anterior, D, dorsal; man, manubrium; Post, posterior; V, ventral.
Fig. 4: Furca of Xenyllodes armatus collected from Bantry, Co. Cork, Ireland in January 1953 by T. Clay. There are two setae (*) on the dens. man, manubrium.
Fig. 5: Anal spines (*) of Xenyllodes armatus collected from Bantry, Co. Cork, Ireland in January 1953 by T. Clay.
Fig. 6: Head of the same specimen of Xenyllodes armatus shown in Fig. 1. The antennae have a characteristic conical shape.