Mackenziella psocoides Hammer, 1953

Schneider, Clement & D'Haese, Cyrille A., 2023, Breakaway from a globular body shape: molecular phylogeny reveals the evolutionary history of the enigmatic springtail Mackenziella psocoides, Arthropod Systematics & amp; Phylogeny 81, pp. 781-799 : 781

publication ID	https://dx.doi.org/10.3897/asp.81.e104522
publication LSID	lsid:zoobank.org:pub:9A2C7973-7127-4C10-9871-513B59D1CF84
persistent identifier	https://treatment.plazi.org/id/9101A9F1-D70C-520D-8B7E-CC95358C6987
treatment provided by	Arthropod Systematics & Phylogeny by Pensoft
scientific name	Mackenziella psocoides Hammer, 1953
status

Treatment

Material examined for morphology.

Eight females and three males on eleven slides; Germany, Saxony, Tauchritz near Görlitz; 51.0689°N, 14.9340°E, alt. 210 m; 12 Feb. 2023; C. Schneider leg.; mosses and shallow substrate on a concrete slab; extracted with Berlese funnel; deposited in the Apterygota collection of the Senckenberg Museum für Naturkunde Görlitz; slides number AA00001 to AA00011. Three females and a male on four slides; two females and three males on a SEM mount plate; same data as above; deposited in the Apterygota collection of the Muséum National d’Histoire Naturelle, Paris; slides number EA060065, EA060066, EA062721 and EA062722 GoogleMaps , SEM plate number EA030050 View Materials .

Additional description.

Our specimens are very similar to the descriptions of Fjellberg (1989, 1998b, 2007), which we do not intend to fully repeat here. Nonetheless, we report a few additional observations and precisions.

Habitus as in Figs 1D-K, 3A-E.

Male with a higher ratio length head/trunk than female (Fig. 3A-D View Figure 3 ). Clypeal area reduced (Figs 3E View Figure 3 , 5A View Figure 5 ). Dorsally on head, with a deep transverse groove posterior to the eyes (Fig. 3A, C, D View Figure 3 ). With a dorsal bulge b at the head-Th. I insertion (Fig. 3A, D View Figure 3 ). With four dorsal bulges corresponding to Th. II-Abd. III, well-marked in either living, ethanol preserved and dried specimens (Figs 1D-J View Figure 1 , 3A, C, D View Figure 3 ), but almost erased in lactic-acid induced swollen specimens. Abd. I and II bulges well-marked in male, but faint in female (Fig. 3A, C, D View Figure 3 ). Abd. IV delimited from Abd. V by a faint groove (Fig. 3A, C, D View Figure 3 ). Dorsally, Abd. III + IV region twice as long as Abd. I + II. Ventrally, retinaculum (Abd. III appendage) at mid-distance between the ventral tube (Abd. I) and the furca (Abd. IV appendage). Furca short, barely reaching the posterior side of the ventral tube when folded.

Integument.

Integumentary secondary granules resulting from simple and individual outgrown primary granules (increased in size and elevated above the ordinary primary grain) (Fig. 6E View Figure 6 ). Presence limited to: postantennal area dorsally to the eyes (Fig. 5A, B View Figure 5 ), head-Th. I dorsal bulge, dorsal and lateral part of Th. II-Abd. V (Figs 3A, C, D View Figure 3 , 6A View Figure 6 ). Absent from clypeal area and mouth part (Fig. 5A View Figure 5 ) and from all appendages. Dorso-median line of Th. II-Abd. III not marked, but terminal tubercle t present as a roundish prominence without secondary granules (Figs 3A View Figure 3 , 6E View Figure 6 ). Linea ventralis straight, without additional integumentary channels (Fig. 4A View Figure 4 ), associated with three pairs of tubercles (Fig. 4A View Figure 4 ). Males without vesicles on Th. III.

Antennae.

Chaetae smooth, without ornamentation (Fig. 4B-F View Figure 4 ). Most of the long chaetae of Ant. IV with a rounded apex (Fig. 4C-E View Figure 4 ). Male also with two long s-chaetae with rounded apex on Ant. III and three on Ant. II (Fig. 4B, E, F View Figure 4 ); ms on Ant. III as a microchaetae (Fig. 4B, F View Figure 4 ) (otherwise as described in Fjellberg 1989).

Mouth.

Mouth as in Fig. 5C View Figure 5 , without oral fold nor maxillary outer lobe. Labrum and labium as described in Fjellberg (1989, 1998b).

Legs.

Tibiotarsus I apical row with chaeta ja flattened with an external groove, and apressed to the tegument (not erected), on ventral side (Fig. 6B View Figure 6 ). Unguis with a dorsal smooth lamella splitted in two basally, the two anterior and posterior halves each joining with a small pseudonichya, the dorsal, basal side of the claw forming a depression covered with primary grain (Fig. 6C View Figure 6 ). Unguiculus I to III respectively with: apical filament, short apical filament, no apical filament (Fig. 6B-D View Figure 6 ); unguiculus tri-lamelate, each lamella with a smooth ridge (Fig. 6B-D View Figure 6 ).

Furca.

Posterior part of dens with up to four chaetae ornamented with spicules (discovered with SEM, apparently smooth in some specimens) (Fig. 7B-D View Figure 7 ). Mucro either separate or fused to the dens (as reported in Fjellberg 1989 for juveniles), but fused form may be found in apparently mature specimens. Mucro posteriorly without lamellae, anteriorly, with a smooth lamella, either with an inner groove (separate mucro form) or not (fused mucro form). This smooth lamella extending to the apex of the mucro and shaping its rounded tip.

Other ventral organs.

Sternite of Abd. IV with a pair of small chaetae (Fig. 7A View Figure 7 ) not mentioned in Fjellberg (1989). This pair of chaetae sometimes missing or incomplete (only on one side). Probably homologous to the ventral-anterior field of chaetae found on Abd. IV of most Symphypleona . Ventral tube of the male simple (Fig. 5D View Figure 5 ). Retinaculum simple, with 3+3 teeth and no basal tubercle (Fig. 7E View Figure 7 ).