Licnodamaeus costula Grandjean, 1931

Seniczak, Stanisław, Ayyıldız, Nusret & Seniczak, Anna, 2012, Setal losses in the dorsal hysterosoma of Plateremaeoidea (Acari: Oribatida) in the light of ontogenetic studies, Journal of Natural History 46 (7 - 8), pp. 411-451 : 425-436

Licnodamaeus costula Grandjean, 1931

( Figures 9B,C , 10 , 11A , 12A , 13–17 , 18A , 19 )

Diagnosis

Adult dark brown and rather small (245–260 µm), cuticle reticulate ( Figures 10 , 11A , 12A , 13 , 14 ). Prodorsal setae ro and le thick, and rather long, setae ex and in short ( Table 1). Sensillus with spatulate, barbed head.

Notogaster with six pairs of setae, and large lyrifissures ia, im and ip. Zone between notogaster and anogenital region with longitudinal stria ( Figure 11A ). Six pairs of small genital setae, posterior pair separated from other setae ( Figures 12A , 14C,D ), setae of p -series as long as h -series. Body and longer setae covered with granular cerotegument. Formula of leg setae (and solenidia): I – 1-5-4(1)-5(2)-18(2); II – 1-4-4(1)-4(1)-16(2); III – 2-2-2(1)-4(1)-13; IV – 1-2-2-3(1)-13. Legs tridactylous.

Juveniles unpigmented, with plicate cuticle, body and setae covered with granular cerotegument. Prodorsal and gastronotal setae short, sensillus with spatulate, barbed head. Larva with 12 pairs of gastronotal setae, nymphs with nine pairs; gastronotal setae of nymphs in marginal position. Nymphs rarely with one exuvial scalp of previous instar, and lack excrescence in posterior part of body.

Description of juvenile stages

Larva unpigmented, with plicate cuticle, subtriangular prodorsum, and lateral depressions on levels of legs I and II ( Figure 15 ). Prodorsal setae short, length decreasing from ro to in, seta ex as short as in ( Table 1). Bothridium oval, sensillus with spatulate head.

Gastronotum with 12 pairs of small setae, including h 3 positioned laterally to posterior part of anal opening ( Figure 16A ). Paraproctal valves (segment PS) with two pairs of small setae. Cupule ia posterior to seta c 3, cupule im anterior to seta lm, cupule ip between setae h 1 and h 2, cupule ih lateral to anterior part of anal opening, gland opening gla anterolateral to seta h 3. Body and most setae covered with granules of cerotegument.

Nymphs unpigmented, plicate, with relatively shorter prodorsum, comparing to larva; body and setae covered with granular cerotegument. Gastronotum of protonymph with nine pairs of setae (l -series and d -series lost, p -series added), which remain in deutonymph and tritonymph; all setae short. Genital valves of protonymph with pair of short setae ( Figure 16B ), two pairs added in deutonymph ( Figure 17A ) and two more pairs added in tritonymph ( Figure 17B ). One pair of aggenital setae appears in deutonymph, posterolateral to genital valves, and remains in tritonymph. Paraproctal valves of protonymph (segment AD) and deutonymph (segment AN) glabrous, those of tritonymph with two pairs of small setae. In deutonymph three pairs of small adanal setae (ad 1 – ad 3) appear on segment AD, and remain in tritonymph. Nymphs rarely with single exuvial scalp of previous stage ( Figure 18A ), loosely connected to gastronotum, and without excrescence in posterior part of body.

Shape of prodorsum and prodorsal setae of tritonymph ( Figure 19 ) as in larva. Gastronotal setae small, inserted marginally on gastronotum, leaving central region glabrous. Posterior setae slightly longer, and distinctly thicker than anterior setae. Gland opening gla anterior to seta p 3. Cupules ia and im as in larva, cupule ip between setae p 1 and h 2, cupule iad lateral to anterior part of anal opening, cupules ips and ih pushed laterally from anal opening. Tarsus I rather short, with two curved solenidia, ω 1 longer than ω 2, tarsus and some setae covered with granular cerotegument, famulus ε not observed ( Figure 9B,C ). Tibia with two solenidia, ϕ 1 long, ϕ 2 short, setae l covered with granular cerotegument.

Ontogenetic transformations

During ontogeny of Licnodamaeus costula five pairs of setae are present on the prodorsum, including a sensillus. In all instars all prodorsal and gastronotal setae are short, but anterior setae on the prodorsum are longer than posterior setae, while posterior setae on the gastronotum are longer than anterior setae. In all instars the sensillus has a spatulate head. The larva has 12 pairs of gastronotal setae, the protonymph has nine pairs (d -series and l -series lost, p -series added), while the adult loses setae of c -series ( Table 2), so that six pairs of notogastral setae remain (h -series and p -series). The nymphs and adult rarely bear a single exuvial scalp of previous stage, and have no posterior excrescence. The formula of gastronotal setae is 12-9-9-9-6 (larva to adult), formulae of coxisternal setae are as in Al. setosus , the formula of genital setae is 1-3-5-6 (protonymph to adult), and that of segments PS–AN is 23333-0333-022 ( Table 3).

Distribution and ecology

Licnodamaeus costula is a Mediterranean species ( Subías 2004, 2011; Caruso et al. 2005), and is considered xerophilous ( Murvanidze et al. 2008). Mihelčič (1964) noted it in dry steppe soil of East Tyrol ( Austria), while Arroyo and Iturrondobeitia (2004) found it in Mediterranean oak forests (plant associations Cephalanthero–Querceto faginae sigmetum and Veronico jabalambrensis–Thymetum mastigophori) in surroundings of Boxed (Burgos province, Spain). This species occurred in several habitats of Castilian upland steppes, like dry crop lands, pastures, pine wood, Portuguese oak forest ( Quercus faginea Lam. ) and Pyrenean oak forest ( Quercus pyrenaica Willd. ), and is considered ubiquitous ( Arroyo et al. 2005), but the highest density achieved in pastures ( Arroyo and Iturrondobeitia 2006). Caruso et al. (2005) found Licnodamaeus costula on the slope of Monte Vulcano on Linosa Island (Pelagian Islands), whereas Moraza (2006) recorded it from evergreen oak forest near Navarra (north of Spain). In our samples from Turkey, this species occurred in mosses on large stones in steppe vegetation near the Erciyes University Experimental Station (38 ◦ 32.31 ′ N, 035 ◦ 31.84 ′ E, 2190 m above sea level). This is a new record for the fauna of Turkey ( Özkan et al. 1988, 1994; Erman et al. 2007).

(Continued)

Figures

Figure 9. Tarsus I and part of tibia I of tritonymph, scale bars 20 µm. (A) Aleurodamaeus setosus, paraxial aspect; (B) Licnodamaeus costula, fragment of tarsus with solenidia; (C) L. costula, paraxial aspect; (D) Licnobelba latiflabellata, fragment of tarsus with solenidia; (E) L. latiflabellata, paraxial aspect. Explanation of labels in text.

Figure 10. Licnodamaeus costula, adult, dorsal aspect, scale bar 50 µm. Legs partially drawn. Explanation of labels in text.

Figure 11. Lateral aspect of adults, scale bars 100 µm. (A) Licnodamaeus costula; (B) Licnobelba latiflabellata. Legs partially drawn. Explanation of labels in text.

Figure 12. Adult, anogenital region, scale bars 50 µm. (A) Licnodamaeus costula; (B) Licnobelba latiflabellata. Explanation of labels in text.

Figure 13. Licnodamaeus costula, adult, scanning electron micrographs. (A) Dorsal aspect; (B) prodorsum and anterior part of notogaster; (C) lateral aspect; (D) proterosoma, lateral aspect.

Figure 14. Licnodamaeus costula, adult, scanning electron micrographs. (A) Ventral aspect; (B) gnathosoma; (C) anogenital region; (D) genital region.

Figure 15. Licnodamaeus costula, larva, dorsal aspect, scale bar 50 µm. Legs partially drawn. Explanation of labels in text.

Figure 16. Licnodamaeus costula, scale bar 50 µm. (A) Anal region of larva; (B) anogenital region of protonymph. Explanation of labels in text.

Figure 17. Licnodamaeus costula, anogenital region, scale bars 50 µm. (A) Deutonymph; (B) tritonymph. Explanation of labels in text.

Figure 18. Lateral aspect of tritonymphs, scale bars 100 µm. (A) Licnodamaeus costula; (B) Licnobelba latiflabellata. Legs partially drawn. Explanation of labels in text.

Figure 19. Licnodamaeus costula, tritonymph, dorsal aspect, scale bar 50 µm. Legs partially drawn. Explanation of labels in text.