Bochartia kuyperi Oudemans, 1910

Mąkol, Jeanette Stålstedt Andreas Wohltmann Johannes Bergsten Joanna, 2016, Towards resolving the double classification in Erythraeus (Actinotrichida: Erythraeidae): matching larvae with adults using 28 S sequence data and experimental rearing, Organisms Diversity & Evolution 16 (4), pp. 761-790 : 784-786

Rhyncholophus regalis C.L. Koch, 1837 Bochartia kuyperi Oudemans, 1910 , syn. nov. Erythraeus gertrudae Haitlinger, 1987 , syn. nov.

Erythraeus sp. A .: Wendt (1996)

Erythraeus nivalis (sic!): Wohltmann (2001)

Type material: Neotype (NHRS-ACAR 000000097), female (for the place of origin, see Table 1, locality 23, collection date: 24 May 2015), mounted on one slide, is deposited in the Swedish Museum of Natural History , Stockholm, Sweden.

Diagnosis (data for neotype given in parentheses)

Adult: Palp genu: 0–3 (2) conalae, 0–2 (0) semi-conalae; palp tibia: 2–5 (5) conalae, 0–2 (0) semi-conalae; anterior sensillary area of crista metopica with anterior process and with 8–12 (12) non-sensillary setae; dorsal opisthosomal setae uniform in shape, straight or only slightly bent, narrowing apically, with slender, husk-like setules; serratalae on legs I–II slender, on legs III– IV moderately developed (see Fig. 12 for comparison)

Larva: AL not inflated basally, ASens relatively long (50– 76), fD = 30–42, fnbFe = 3-3-3, Ti III 310–385

Description

Adult: Fig. 12 ; metric data: Table 3; meristic data: Table 5

Color in life reddish-brown

Gnathosoma: Chelicerae typical for the genus; palps with relatively sparse setation; normal, setulated setae present on palp trochanter and palp femur; palp genu with almost smooth, slender setae (slightly thicker at dorsal side of the segment), zero to three conalae and zero to two semi-conalae; palp tibia with normal, sparsely barbed setae and with two to five conalae and zero to two semi-conalae; odontus hook-like; palp tarsus rounded at termination, with the apical part overreaching the termination of odontus, densely covered with eupathidia and solenidia

Idiosoma: Scutum indistinct, not extended beyond crista metopica; anterior process of ASA relatively narrow, posterior process of PSA absent; ASens and PSens covered with very tiny barbs; on ASA—8–12 setae AL; ocular plates (73–88 × 108–127), located laterally to crista, behind the half of its length; dorsal setae (50–175) uniform in shape, only slightly narrowing apically, densely covered with husk-like setules (more delicate than in E. cinereus ); setules adnate in proximal part of the stem, become more outstanding towards stem termination; ventral setae much more slender than dorsal ones, needle-like, covered with short bristles; GOP surrounded by paired sclerites (genital plates: epivalves and centrovalves), located at the level of coxae III–IV; setae covering valves similar to VS, slender, with delicate barbs; AOP surrounded by indistinct paired valves, and of those, the external valves were more sclerotized; setae covering valves similar to those covering genital plates but shorter

Legs: Serratalae present on basifemora, telofemora, genua, and tibiae of all legs; on legs I–II serratalae slender than on legs III–IV; the most stout serratalae occur on tibia IV; of other setae—normal, setulated ones, present on all leg segments (on genua and tibiae—in minority); specialized setae distributed on bFe–Ta; tarsi I–IV terminated in paired claws, each claw covered with fimbriae

Larva: Figs. 13 , 14 , 15 , and 16; metric data: Table 4; meristic data (including leg chaetotaxy): Table 5

Color in life bright red

Gnathosoma ( Fig. 13 ): Cheliceral claw, with distinct subterminal hook on the blade; a pair of smooth, point- ed adoral setae (cs) (33–46), located distally; paired, club-shaped, supracoxal setae (elcp, 5–7) placed dorsally, in antero-lateral position; on ventral side of gnathosoma, a pair of smooth, pointed subcapitular (hypostomal, tritorostral) setae (bs) (56–69) and, in more distal position, a pair of spine-like oral setae (as) (6–15); pedipalp formula: 0-B-B-BBB-BNNNNNωζ z; palp femur and genu, each with one setulated seta dorsally, palpal femoral seta (60–71), slightly shorter than palpal genual seta (79–91); the most proximal seta on palp tibia with short setules, the most distally placed seta (in ventral position) almost smooth; odontus with dorsal, splinter-like branch, arising at half length of claw and not reaching claw termination; palp tarsus with one elongated, barbed seta, and five to six shorter, normal setae (two—with minute setules), one solenidion (ω) and one prominent distal eupathidium (ζ), the latter associated with tiny companion seta (z)

Idiosoma ( Figs. 14 and 15 ): Scutum oval to trapezoidal in shape; AL not widened at base, both AL and PL serrate; ASens shorter than PSens; paired eyes located postero-laterally of scutum, at the level of posterior margin of the sclerite (in unengorged specimens); anterior lens (18–19) and posterior lens (17–19) comparable in size; dorsal setae variable in length (58–127), serrate; NDV = 42–52; seta 1a (60–70) located outside coxal plate I; coxa I with serrate seta 1b (106–120), coxa II with serrate seta 2b (43–44), coxa III with serrate seta 3b (49–53); seta 3a (38–43) located outside coxa III; posterior to coxae III six pseudanal setae (50–58), distinctly thinner than dorsal idiosomal setae

Legs ( Fig. 16 ): Segmentation formula: 7-7-7; solenidion on genu I (25–27) located at ca half length of the segment; proximal solenidion on tibia I (28–30) slightly shorter than the distal solenidion (32–36); both solenidia on tibia located in distal half of the segment, distal solenidion with companala da; solenidion (ω) on tarsus I relatively short (24–28), famulus (ε) (3) small, inconspicuous; subterminal eupathidium on tarsus I also relatively short (32–35) and with accompanying seta z (9), B pretarsal^ eupathidium markedly shorter (17–20), without z; solenidia on tibia II arise at proximal and distal margin of the segment, respectively; proximal solenidion (21–24) longer than the distal one (15); subterminal eupathidium on tarsus II (34–38) with companala z (9), B pretarsal^ eupathidium shorter (23–25), without z; solenidion on tibia III short (22–25), located proximally, B pretarsal^ eupathidium (19–27), without z; median empodium of pretarsi I–III claw-like, with small lateral barbs; anterior claw with terminal hook, posterior claw without terminal hook; both claws aliform

Distribution: Western Palaearctic

Remarks on taxonomy

E. kuyperi and E. gertrudae fall within the range of morphometric characters as measured for larvae of E. regalis . Haitlinger (2003), in the key to larvae of Erythraeus spp. , pointed to differences between E. kuyperi and E. gertrudae expressed in the shape of scutum (oval in E. kuyperi , trapezoidal in E. gertrudae ). Examination of larvae obtained by experimental rearing allowed to attribute the differences to intraspecific variation, thus constitutes the background for species synonymization.

Biology

Field data and laboratory data are provided in Table 2. E . regalis was collected close to water reservoirs, both in meadows and in forested areas, however not at inundated places. A single protonymph was collected in the litter layer in August. Deutonymphs were active at sunny days in August–September and again in March moved around on the litter layer. Outside the time of increased activity, they hid in crevices of the bark of Betula 1–3 m above ground level. In May 16, tritonymphs were found in crevices, most in the bark of birch trees and only few in the litter layer. Adults were active in May–June.

In the laboratory, eggs were deposited by females collected in early summer. Larvae hatched a month later and survived for up to 13 days without hosts (n = 60, 20 °C). When exposed to Aphis sp. , larvae attached to the host at first contact. Further development stopped when reaching the deutonymph instar. Although deutonymphs moved and fed on larvae and pupae of ants and brachyceran flies, none entered the tritonymph when kept at constant 20 °C. However, of ten deutonymphs captured in September and chilled at 5 °C and darkness for 102 days, one entered the tritonymph when subsequently exposed to 20 °C and 16/8 light/darkness. The latter constitutes an evidence for deutonymph being a diapausing and hibernating instar.

Figures

Fig. 1 Majority-rule consensus from the non-clock Bayesian phylogenetic analysis of 28S from Erythraeus larvae and postlarval instars sampled in the field. Numbers above branches denote posterior probability values. The clusters of Erythraeus cinereus, E. regalis, E. sp. 1, and E. sp. 2 have both larvae (gray) and adults (black) included. Curteria episcopalis was used as outgroup to root the tree

Fig. 2 Ultrametric clock tree from Beast showing the maximum likelihood solution of the generalized mixed Yule coalescent model (GMYC). Red lines (thinner lines on the right side of the graph) indicate within-species branches, and black lines (thicker lines on the left side of the graph) represent between-species branches as inferred by the GMYC model

Fig. 12 Erythraeus regalis, adult. a Palp, medial view. b Crista metopica and eyes. c Dorsal opisthosomal setae. d Serratala on genu I. e Serratala on genu IV. f Diversity of serratalae and setae of non-serratalae type on telofemora, genua, and tibiae of legs I–IV

Fig. 13 Erythraeus regalis, larva. a Gnathosoma, ventral view. b Palp tarsus

Fig. 14 Erythraeus regalis, larva. a Gnathosoma and idiosoma, dorsal view. b Dorsal opisthosomal seta. c Gnathosoma and idiosoma, ventral view

Fig. 15 Erythraeus regalis, larva. Scutum

Fig. 16 Erythraeus regalis, larva. a Leg I. b Leg II. c Leg III. d Genu-tarsus I. e Genu-tarsus II. Tibia-tarsus III (d–f, only specialized setae shown)