The morphological ontogeny of Lopheremaeus mirabilis (Csiszár 1962), the type species of LopheremaeusPaschoal, 1988 (Plateremaeidae) is described and illustrated. The adult of this species has six pairs of notogastral setae (lp, h1, h2 and p-series), epimeral and anogenital hypertrichy, and 4–5 pairs of anal setae. The cuticle of juveniles is plicate, the larva lacks the gastronotal setae c3, la, lm and h3, the nymphs are multideficient (they lack also setae of d-series) and eupheredermous, i.e. they carry the exuvial scalps of previous instars on the gastronotum. In the adult, dorsal and ventral crests are present on all femora and trochanter III, and dorsal crest is present on trochanter IV, the nymphs have also dorsal and ventral crests on genua, whereas the larva has no crests. In all instars, seta d on all genua and tibiae is present, and all tarsi have basal bulb (containing muscles) and uniformly narrow distal stalk (with only tendons) at about mid-length. This species was reported only from Bulgaria, Bosnia-Herzegovina and North Macedonia, Romania and Georgia.
Introduction
Lopheremaeus mirabilis (Csiszár 1962) was originally proposed as Plateremaeus mirabilis Csiszár, 1962 based on specimens from Bulgaria (Csiszár & Jeleva 1962), but now this species is known also from Bosnia-Herzegovina, North Macedonia, Romania and Georgia (Tarman 1983; Ivan & Vasiliu 2000; Murvanidze & Mumladze 2016). Paschoal (1988) revised the Plateremaeidae, and appointed it the type species of Lopheremaeus Paschoal, 1988. He presented the main diagnostic characters of the genus as: apodemes poorly sclerotized or absent; bothridial seta long, setiform, with very short spines at distal part, notogaster rounded, seta h1 well developed, epimeral formula 8-7-12-4, genital and anal openings separated, with seven and four pairs of setae, respectively. However, adults of L. mirabilis from Romania studied herein have also three pairs of p-series setae on the notogaster and some individuals have more anal setae, which were not mentioned in Csiszár and Jeleva (1962) paper, modifying the diagnosis of Lopheremaeus given by Paschoal (1988). Subías (2020) included three species in Lopheremaeus, and one of which he considered species inquirenda. According to the catalogue of juvenile oribatid mites by Norton and Ermilov (2014) and further literature, the juveniles of Lopheremaeus are not described and any other member of the family.
The aim of this paper is to describe and illustrate the morphological ontogeny of L. mirabilis.
Material and methods
Sampling
The juveniles and adults of L. mirabilis used in this study were collected on 7 July 2019 by O. Ivan from a Dacian oak-hornbeam forest, located in Eastern Romania (46°40′27″N, 28°03′35″E, 280 m a. s. l.), near the southern limit of the continental bioregion where it contacts the steppe. This forest is about 100 years old (Natura 2000 site), and is composed mainly of Quercus petraea (Matt.) Liebl., Q. dalechampii Ten., Carpinus betulus L. and Tilia tomentosa Moench. We investigated population parameters of L. mirabilis, including density and developmental stage structure. The gender of adults is not visible through the thick, reticulate integument, and therefore metric data (in µm) were based on 15 randomly selected adults, which were dissected in order to determine the gender, number of gravid females and carried eggs, and included: total length (tip of rostrum to posterior edge of notogaster, measured in lateral aspect); maximum width (widest part of notogaster, measured in dorsal aspect); length of anal and genital openings; and length of setae (measured from the appropriate plane).
Studies of type material
We studied the morphology of a specimen of L. mirabilis from the Csiszár collection stored at the Hungarian Natural History Museum (HNHM). This individual is in a good condition, except for legs, which are broken. It is labelled as follows: Plateremaeus mirabilis Csisz., 1962; Bulgaria, Karlovo–Kalofer; 1956 June 9–11, Balogh–Csiszár. Measurements: length—512, width—301.
Illustrations and photographs
The illustrations of L. mirabilis are limited to the body regions that show substantial differences between instars, including the dorsal and lateral aspect and some leg segments of the larva, tritonymph and adult, ventral regions of all instars, and the palp and chelicera of the adult. Illustrations were prepared from individuals mounted temporarily on slides in lactic acid, using the open-mount technique (Grandjean 1949). In the text and figures, we used the following abbreviations: rostral (ro), lamellar (le), interlamellar (in) and exobothridial (ex) setae, bothridium (bo), bothridial seta (bs), notogastral or gastronotal setae (c-, d-, l-, h-, p-series), cupules or lyrifissures (ia, ih, ips, iad), scalps of larva (L), protonymph (Pn) and deutonymph (Dn), subcapitular setae (a, m, h), cheliceral setae (cha, chb), palp setae (inf, l, d, lt, vt, ul, su) and solenidion ω, Trägårdh's organ (Tg), Claparède's organ (Cl), epimeral setae (1a–c, 2a, 3a–c, 4a–c), adanal and anal setae (ad-, an-series), aggenital setae (ag), leg setae (bv, ev, d, l, ft, tc, it, p, u, a, s, pv, pl, v), solenidia (σ, φ, ω) and famulus (ε). Terminology used follows that of Grandjean (1951, 1953) and Norton and Behan-Pelletier (2009). The species nomenclature follows Subías (2004).
For scanning electron microscopy (SEM), the mites were air-dried and coated with Au/Pd in a Polaron SC502 sputter coater and placed on Al-stubs with double-sticky carbontape. Observations and micrographs were made with a ZEISS Supra 55VP scanning electron microscope. Light photographs were prepared from individuals mounted temporarily on slides in lactic acid, using a Leica DM3000 microscope and Leica DFC420 camera.
Lopheremaeus mirabilis (Csiszár, 1962)
(Figs. 1–20)
Plateremaeus mirabilis Csiszár, 1962: Tarman 1983.
Lopheremaeus mirabilis: Paschoal 1988; Subías 2004; Murvanidze and Mumladze 2016.
Diagnosis
Adults of medium size (592–656), oval, with rounded rostrum, and polygonal pattern on prodorsum and notogaster. Bothridial seta setiform, with very short spines near distal end. Notogaster elliptical in dorsal aspect, with six pairs of notogastral setae (lp, h1, h2 and p-series). Formula of epimeral setae 8-7-12-4 (hypertichy occurs), genital setae (seven pairs) in two rows (4 pairs in inner rows, 3 pairs in lateral rows), four pairs of aggenital setae and 4–5 pairs of anal setae; all short and smooth. Adanal seta ad3 inserted roughly in alignment with lateral margin of genital and anal plate, at level about midway between them, other two pairs in lateral position to anal plates. All femora and trochanter III with dorsal and ventral crests, trochanter IV with dorsal crest. Solenidion φ1 on tibia I on large apophysis, covering basal dorsal part of tarsus I, famulus ε on tarsus I short, semispherical. Seta d present on all genua and tibiae, slightly removed from respective solenidion. All tarsi with basal bulb and uniformly narrow distal stalk about mid-length, with three claws and short setae p.
Prodorsum in juveniles reticulate, prodorsal setae ro and le of medium size, setae in and ex short. Bothridial seta clavate in larva, setiform in nymphs. Larva with eight pairs of gastronotal setae (c3, la, lm and h3 absent), nymphs with same number (d-series lost, p-series appears). In larva, crests on legs not evident, nymphs with dorsal and ventral crests on all femora, genua and trochanter III, and dorsal crest on trochanter IV. On all genua and tibiae seta d present, slightly removed from respective solenidion. All tarsi with basal bulb and uniformly narrow distal stalk at about mid-length, with one claw and short setae p.
Morphology of adult
Adult (Figs. 1–8) similar to that described by Csiszár and Jeleva (1962), but see Remarks. Mean length (range) of females 633.3±13.5 (606–656, N=9) and mean width (range) 374.6±13.5 (352–400), and mean length (range) of males 611.0±11.9 (592–624, N=6) and mean width (range) 384.7±42.1 (352–468). Setae ro and le (Figs. 1a, 2, 3a, 5a–c, 6a, 6d, Table 1), and bothridial seta (Figs. 1c, 5a–c, 6a–c) as in Csiszár and Jeleva (1962). Notogaster reticulate (Figs.1a, 1b, 3a, 5, 6a–c, 7a, 8a), setae (6 pairs, lp, h1, h2 and p-series) strongly curved inwards, smooth and long (Table 1), p-series slightly thinner than others (Figs. 1a, 2, 3a, 5d, 7a, 8a). Subcapitular setae h, and m slightly longer than a, all smooth. Formula of epimeral setae 8-7-12-4 (I–III hypertrichous, variation not observed); setae in first row of epimere I clearly longer than others, all smooth (Fig. 2). Genital setae (7 pairs) in two rows, inner setae (4 pairs) and lateral setae (3 pairs) of similar length, all smooth. Aggenital setae (4 pair) similar to genital setae. Adanal seta ad3 inserted roughly in alignment with lateral margin of genital and anal plate, at level about midway between them; all strongly curved and smooth. Anal setae (4–5 pairs) similar to genital setae. Chelicera relatively slim, seta cha longer than chb, both barbed, in some individuals second seta chb present (Figs. 3b, 3c). Palp relatively short and thin, solenidion ω separated from seta acm (Fig. 3d). Formula of palp setae (and solenidion): 0-2-1-3-9(1). Setae sup, inf, l" and d finely barbed, other setae and eupathidia shorter, smooth. Leg segments protected by retrotecta. All femora and trochanter III with dorsal and ventral crests, trochanter IV with dorsal crest (Figs. 1a, 2, 3a, 4, 5b, 5d, 7a–c, 8b–d). Most leg setae relatively long, strongly curved and smooth, most distal setae on tarsi slightly curved or almost straight and finely barbed. Solenidion φ1 on tibia I long, on large apophysis, covering large dorsal part of tarsus I; tarsal solenidia ω1 and ω2 clearly shorter, other solenidia short. Famulus ε semispherical (Figs. 4a, 7d, 8b). Seta d present on all genua and tibiae, removed from the respective solenidion (Fig. 4). All tarsi with basal bulb (containing muscles) and uniformly narrow distal stalk (with only tendons) at about mid-length, with three claws and short setae p (Figs. 4, 7d, 8b). Some parts of leg segments and leg setae covered with granular cerotegument. Formulae of leg setae (and solenidia, from trochanter to tarsus): I–1-6-4(1)-5(2)-20(2); II–1-5-4(1)-5(1)-15(2); III–3-5-3(1)-4(1)-15; IV–3-5-3-4(1)-12.
Remarks
Females and males investigated herein are slightly larger than those studied by Csiszár and Jeleva (1962) — holotype length 530, width 312, sex not investigated – and have three pairs of setae of p-series, which were overlooked by these authors. The topotype specimen from HNHM is smaller (512 × 301) than holotype, has the notogastral setae of p-series (strongly curved, visible in ventral and posterior aspects) and dorsal crest on trochanter III. The adults from Romania have more crests on the legs, 4–5 pairs of anal setae (versus four pairs in Csiszár and Jeleva 1962), but not observed by Csiszár and Jeleva (1962). These authors mentioned in Plateremaeus Berlese, 1908 crispins (or retrotecta) on legs and 4–5 pairs of anal setae, but this genus was further divided in Plateremaeus and Lopheremaeus (Paschoal 1988). In our individuals, the shape of leg setae, solenidion φ1 on tibia I and famulus ε on tarsus I are similar as in Csiszár and Jeleva (1962). All these characters widen the diagnosis of Lopheremaeus given by Csiszár and Jeleva (1962).
Description of juvenile stages
Larva oval in dorsal aspect (Figs. 9a, 10a) and unpigmented. Prodorsum subtriangular, prodorsal setae ro and le of medium size (Table 1), in and ex short. Mutual distance between setal pairs le and in about two times longer than between pair ro. Seta le inserted closer to ro than to in. Bothridium large, rounded, bothridial seta long, clavate and barbed. Central part of prodorsum reticulate, posterior part punctate, and ridge present between bothridium and central part of prodorsum (Figs. 9b, 10a). Some parts of body and most setae covered with granular cerotegument.
Gastronotum of larva plicate, relatively flat, with horizontal edge and eight pairs of setae, including h2 inserted lateral to medial part of paraproctal valves (Figs. 10a, 11a, 12a), setae c3, la, lm and h3 not observed. Setae c1 and of c2 short (Table 1), other setae of medium size, all curved, inserted on small apophyses and covered with granular cerotegument, but setae of d-series with thicker granular cerotegument than other setae, and appearing barbed. Cupule ih lateral to anterior part of anal valves, other cupules and gland opening not observed in plicate integument. Paraproctal valves (segment PS) glabrous.
All tarsi with thick basal bulb and uniformly narrow distal stalk at about mid-length, with one claw and short setae p (Figs. 9a, 13). Crests on legs not evident. Solenidion φ1 on tibia I on large apophysis, covering large dorsal part of tarsus I, other solenidia short or of medium size, famulus ε on tarsus I relatively long, with apical globule. Most distal setae on tarsi long, slightly curved or nearly straight, other setae long or of medium size and curved; all smooth. Seta d present on all genua and tibiae, removed from the respective solenidion. Some parts of leg segments and setae covered with granular cerotegument.
Shape and colour of nymphs (Figs. 9c, 9d) as in larva, but prodorsal seta ro and le relatively longer (Table 1), strongly curved inwards, and le inserted closer to ro than in larva, setae in and ex short. Bothridium rounded, with posterolateral edge, bothridial seta setiform, covered with granular cerotegument. In protonymph, anterior and medial part prodorsum reticulate, and lateral and posterior parts punctate. Gastronotum with eight pairs of setae: p-series appears in protonymph (Fig. 11b) and remains in deutonymph and tritonymph (Figs. 14a, 14b), and d-series lost and remains absent through rest of ontogeny. In all nymphs, setae c1 and c2 short, h1 long, and other setae of medium size (Table 1). Dorsal part of gastronotum flat, with exuvial scalps of previous instars, other gastronotal setae in marginal position on gastronotum (Figs. 15b, 18, 19b). Seta h1 curved upwards and can be helpful in carrying exuvial scalps. Genital valves of protonymph with one pair of setae, three pairs added in deutonymph (one pair in inner row and two pairs in outer row), and one pair added in tritonymph in inner row (Figs. 1b, 14a, 14b); all short and usually covered with granular cerotegument. In deutonymph, one pair of aggenital setae appearing and remaining through ontogeny. Paraproctal valves of protonymph (segment AD) and deutonymph (segment AN) glabrous, but in tritonymph 4–5 pairs of anal setae present, all short and smooth. In protonymph, cupule ips lateral to anal valves, other cupules and gland opening not observed, possibly obscured by granular cerotegument in this and other nymphs (Figs. 11b, 14a, 14b).
In all nymphs, hypertrichy present in epimeral region, variation not observed. In protonymph, one pair of setae added on epimere II, and one pair on epimere III, compared to larva (Figs. 16a, 16b), in deutonymph three pairs of setae added on epimere III, and one pair added on epimere IV (Figs. 17b, 17a), compared to protonymph. In tritonymph, four pairs of setae added on epimere I, three pairs added on epimere II, one pair added on epimere III, and two pairs added on epimere IV, compared to deutonymph (Figs. 17a, 17b).
In nymphs, dorsal and ventral crests present on trochanter III, all femora and genua, and dorsal crest present on trochanter IV (Figs. 12b, 18, 19, 20). Solenidion φ1 on tibia I on large apophysis, covering large dorsal part of tarsus I, other solenidia short or of medium size, famulus ε on tarsus I semispherical. On all genua and tibiae, seta d present, removed from respective solenidion (Fig. 20). All tarsi with basal bulb and uniformly narrow distal stalk at about mid-length, with one claw and short setae d. Most distal setae on tarsi long, slightly curved or nearly straight and finely barbed, other setae long or of medium size, curved and smooth. Some parts of leg segments and leg setae covered with granular cerotegument.
Summary of ontogenetic transformations
In all juveniles of L. mirabilis, the prodorsal setae ro and le are of medium size, while in and ex are short; by contrast, in the adult seta ex is of medium size, but shorter than ro and le. In all instars, the opening of the bothridium is rounded, but the bothridial seta is clavate in the larva, and setiform in other instars. The larva has eight pairs of gastronotal setae (c-, d-series, lp, h1, h2), and the nymphs have also eight pairs (p-series appears, d-series is lost in protonymph), but the notogaster of the adult loses the c-series, such that six pairs of notogastral setae remain. The formula of gastronotal setae of L. mirabilis is therefore 8-8-8-8-6 (from larva to adult). Formulae of epimeral setae are: 3-1-2 (larva, including scaliform 1c), 3-2-3-1 (protonymph), 3-2-6-2 (deutonymph), 7-5-7-4 (tritonymph) and 8-7-12-4 (adult). Formula of genital setae is 1-4-5-7 (protonymph to adult), aggenital setae is 1-1-4 (deutonymph to adult), and segments PS–AN is 03333-0333-0(4-5)(4-5). Seta d is present on genua and tibiae of all instars. The ontogeny of leg setae and solenidia is given in Table 2.
Distribution, ecology and biology
According to Subías (2004, 2020), L. mirabilis has an eastern Mediterranean distribution, and this species was reported only from Bulgaria, Bosnia-Herzegovina and North Macedonia, Romania and Georgia (Csiszár & Jeleva 1962, Tarman 1983, Ivan & Vasiliu 2000, Murvanidze & Mumladze 2016). This species inhabits alpine meadows, forests and urban soils (Murvanidze & Mumladze 2016). It was collected in Romania for the first time in 1992 in a small number (Ivan & Vasiliu 2000), but was misidentified as Lopheremaeus laminipes (Berlese 1916). Our additional collection and the comparison with a specimen from the Csiszár collection allowed us to identify these individuals as L. mirabilis. Thus, this is the first record of L. mirabilis in Romania, and represents the most northern record of the species.
In our study, the density of L. mirabilis in the soil of Dobrina forest (Romania) varied between May and July, being highest in June 2014 (6.4 individuals per 500 cm3), and lowest in May 1992 (0.4 individuals per 500 cm3, Table 3). In most samples, adults dominated the juveniles, comprising 41–64% of individuals. In the sample with the most abundant juveniles (July 2019), the juveniles dominated (64% of individuals) the adults, and the stage structure of L. mirabilis was the following: seven larvae, four protonymphs, four deutonymphs, three tritonymphs and 10 adults. Among 15 dissected adults, nine were females and six males, but we rather not like to give the sex ratio of this species because these mites were collected in different dates. Most females (78%) were gravid, carrying 1–3 (mostly two) relatively large eggs, each 247–271 × 181–199, and one of which constitutes about 40% of the total body length of females.
FIGURE. 1–2.
Lopheremaeus mirabilis, adult, legs partially drawn, scale bars 50 µm. 1. (a) Dorsal aspect, (b) central part of notogaster, (c) bothridial seta (b, c, enlarged). 2. Ventral aspect.
FIGURE 3.
Lopheremaeus mirabilis, adult. (a) Lateral aspect, legs partially drawn, scale bar 50 µm; mouthparts, right side, scale bars 10 µm; (b) chelicera, (c) part of chelicera of another individual, (d) palp.
FIGURE 4.
Lopheremaeus mirabilis, leg segments of adult (part of femur to tarsus), right side, seta on the opposite side not illustrated, but indicated in the legend, scale bar 20 µm. (a) Leg I, tarsus (pl′); (b) leg II; (c) leg III; (d) leg IV; (e) part of femur and genu IV (slightly enlarged).
FIGURE 5.
Lopheremaeus mirabilis, adult, SEM micrographs. (a) Dorsal view, (b), lateral view, (c) frontal view, (d) posteroventral view.
TABLE 1.
Measurements of some morphological characters of juvenile stages and adult of Lopheremaeus mirabilis (mean measurements of 3–7 juveniles and 10 adults in µm); Nd—not developed.
Comparison of morphology of Lopheremaeus mirabilis with congener and remarks
The adult of L. mirabilis is morphologically similar to that of L. laminipes, but Csiszár and Jeleva (1962) recognized the latter species as distinct mainly by the lighter cerotegument and notogastral sculpture, without dense black punctation, and more posterior location of all notogastral setae in the latter species. However, in the figure of L. laminipes drawn by Mahunka and Mahunka-Papp (1995) the location of posterior setae on the notogaster is similar to that of L. mirabilis as shown by Csiszár and Jeleva (1962) and specimens studied herein, which suggests that the distinction of these species needs more investigation.
The homologies of notogastral setae in the adult of L. mirabilis are inconsistently reported in the literature. Csiszár and Jeleva (1962) observed only three pairs of notogastral setae, and labeled none of them. Paschoal (1988) revised the Plateremaeidae and used the old Grandjean's (1951) “Dometorina nomenclature” of notogastral setae, but he treated the notogastral setae r2 and r3 as homologes of lp and lm, respectively, which is inconsistent with Grandjean's (1951) unideficient nomenclature. In our opinion, setae r2 and r3 are located posterior to porose areas A1 and A2, respectively, and should be labeled as h3 and h2, respectively. In the case of L. mirabilis, the adult has no porose areas, seta h3 is absent in the larva, and it is difficult to judge if this seta appears in the protonymph because normally this seta occupies the lateral position, as seta lp, which is present in the larva. There is no trace that h3 appears in the protonymph and lp is lost, and therefore we consider seta lp in all nymphs and adult of L. mirabilis.
FIGURE 7.
Lopheremaeus mirabilis, adult, SEM micrographs. (a) Legs III and IV, dorsal view, (b) legs I and II, dorsal view, (c) femur and part of genu III, lateral view, (d) tarsus I, lateral view (arrow points famulus ε).
FIGURE 8.
Lopheremaeus mirabilis, adult, photo, scale bars 50 µm. (a) Notogaster, dorsal view, (b) part of leg I, lateral view (arrow points famulus ε), (c) femur and genu III, lateral view, (d) femur IV, dorsal view (setae broken).
TABLE 2.
Ontogeny of leg setae (Roman letters) and solenidia (Greek letters) of Lopheremaeus mirabilis.
The presence of epimeral hypertrichy and crests on some leg segments support the membership of L. mirabilis in Plateremaeidae. Epimeral hypertrichy also occurs in Plateremaeus, Allodamaeus Banks, 1947, Paralopheremaeus Paschoal, 1988 and Calipteremaeus Paschoal, 1988; and in Paralopheremaeus small crests also are present on some leg segments (Paschoal 1988). Epimeral hypertrichy also occurs in Hermannia reticulata Thorell, 1871 and H. scabra (Koch 1879), but in L. mirabilis and H. reticulata hypertrichous are epimeres I–III, whereas in H. scabra epimeres III and IV (Seniczak et al. 2017a, b).
Seniczak and Seniczak (2011) and Seniczak et al. (2012, 2016) compared the morphological ontogeny of some species of Plateremaeoidea, and the juveniles of L. mirabilis are most similar to those of Gymnodamaeus bicostatus (Koch 1836), which have plicate cuticle. However, the larva of G. bicostatus has 11 pairs of gastronotal setae (h3 absent), whereas that of L. mirabilis has eight pairs (c3, la, lm and h3 absent). The nymphs of the former species have 10 pairs of gastronotal setae (lp, c-, h- and p-series), whereas those of the latter species have eight pairs (c1, c2, lp-series, h1, h2 and pseries). The adult of G. bicostatus retains five pairs of notogastral setae (h1, h2 and p-series), whereas that of L. mirabilis retains six pairs (lp, h1, h2 and p-series). The nymphs of both species carry the exuvial scalps, but L. mirabilis has long, curved upwards seta h1, which can be helpful in carrying the scalps, whereas in G. bicostatus this seta is short (Seniczak & Seniczak 2011). Aleurodamaeus setosus (Berlese 1883), Arthrodamaeus italicus (Berlese 1916), A. mongolicus Bayartogtokh & Weigmann, 2005 and Licnobelba latiflabellata (Paoli 1908) have also long, curved upwards seta h1, which can be helpful in carrying the exuvial scalps (Seniczak et al. 2012, 2016).
FIGURE 9.
Lopheremaeus mirabilis, photo, dorsal view. (a) Larva, (b) anterior part of body of larva, (c) tritonymph without exuvial scalps, (d) prodorsum of tritonymph. Scale bars (um): a —100; b, d —50 um; c — 200.
FIGURE 10–11.
Lopheremaeus mirabilis, legs partially drawn, scale bars 20 µm. 10. (a) Larva, dorsal aspect, (b) edge of gastronotum (enlarged). 11. Ventral part of hysterosoma, (a) larva, (b) protonymph.
FIGURE 12.
Lopheremaeus mirabilis, lateral aspect, legs partially drawn, scale bar 50 µm. (a) Larva, (b) tritonymph.
FIGURE 13.
Lopheremaeus mirabilis, leg segments of larva (part of femur to tarsus), right side, seta on the opposite side not illustrated, but indicated in the legend, scale bar 10 µm. (a) Leg I, genu (l′); (b) leg II; (c) leg III, (d) part of tarsus, dorsal aspect.
TABLE 3.
Density (individuals/500cm3), stage structure and vertical distribution of Lopheremaeus mirabilis in the soil of Dobrina forest (Romania); L—larva, Pn—protonymph, Dn—deutonymph, Tn—tritonymph, Juv—juveniles, Ad—adult, Olf—litter and fermentation layer, Ah—humus layer, C—constancy in five samples (in%).
FIGURE. 14–15.
Lopheremaeus mirabilis, legs partially drawn, scale bars 50 µm. 14. Ventral part of hysterosoma, (a) deutonymph, (b) tritonymph. 15.Tritonymph, (a) dorsal aspect, (b) reticulation of prodorsum, (c) edge of gastronotum (b, c, enlarged).
FIGURE. 16–17.
Lopheremaeus mirabilis, epimeral regions, partially drawn, scale bars 50 µm. 16. (a) Larva, (b) protonymph. 17. (a) Deutonymph, (b) tritonymph.
FIGURE 18.
Lopheremaeus mirabilis, tritonymph with exuvial scalps, dorsal view. (a) Whole body, (b) prodorsum and gastronotum, (c) prodorsum, (d) legs III and IV.
Acknowledgements
We thank Prof. Dr. Roy A. Norton (State University of New York, Syracuse, New York, USA) and anonymous reviewer for thorough review of the manuscript and very helpful suggestions that improved the scientific value of this paper. We also thank Dr. László Dányi, the curator of the Soil Zoology Collection in the Hungarian Natural History Museum, Budapest, for loan of a specimen of L. mirabilis for our study, and are grateful to Eng. Irene Heggstad (Department of Earth Science, University of Bergen) for her professional help with SEM images. The ecological part of our investigation was supported by a grant of Romanian Ministry of Research and Innovation through Program 1, contract no. 22PFE / 2018. This study was done under the program of the Polish Minister of Science and Higher Education "Regional Initiative of Excellence" in 2019–2022 (Grant No. 008/ RID/2018/19).
