Coecobrya lanna, Zhang & Deharveng & Chen, 2009

Zhang, Feng, Deharveng, Louis & Chen, Jian-Xiu, 2009, New species and rediagnosis of Coecobrya (Collembola: Entomobryidae), with a key to the species of the genus, Journal of Natural History 43 (41 - 42), pp. 2597-2615 : 2599-2602

Coecobrya lanna sp. nov.

( Figure 1)

Types

Male holotype, seven female paratypes. Thailand, Changwat Chiang Mai: Amphoe Chiang Dao, Doi Chiang Dao , in the doline of shaft P1, forest litter, 1720 m above sea level, 11 July 1985, Berlese extraction (sample DC –007). Holotype and four paratypes on slide in MNHN, three paratypes on slide in NJU.

Description

Body length up to 2.0 mm. Ground colour pale yellow in alcohol.

Antenna 1.88–2.41 times as long as cephalic diagonal. Antennal segments as I: II: III: IV = 1: 1.5–2.0: 1.0–1.5: 2.4–3.5, with Ant. IV 2 to 2.3 longer than Ant. III. Antennal chaetae of six main types:

(1) ciliate, long or short, apically pointed or blunt chaetae (few in Ant. I and II);

(2) numerous short, smooth, straight chaetae on Ant. IV;

(3) smooth, straight microchaetae at base of antennae: three dorsal, two ventral on Ant. I; one internal, one external and one ventral on Ant. II;

(4) curved, thin S-chaetae on Ant. II–IV;

(5) rod-like chaetae, 1–2 dorso-distal on Ant. II (absent on Ant. I);

(6) short, thin chaetae on Ant. I–IV.

Ant. III organ with chaetae 2 and 3 rod-like, chaeta 5 shorter than 2, chaeta 8 stronger than others ( Figure 1A).

Eyes absent. Lateral process of labial palp straight, slightly thicker than normal chaetae, with tip reaching beyond apex of labial papilla ( Figure 1B). Subapical chaeta of maxillary outer lobe large, slightly larger than apical one; three smooth sublobal hairs on maxillary outer lobe ( Figure 1C). Chaetae of labial base as M 1, R, E, L 1, L 2, all smooth; R half as long as chaeta M 1; chaeta X 2 ciliate, smooth, or absent; chaetae X and X 4 as smooth microchaetae; chaeta X 3 absent ( Figure 1D). Cephalic dorsal chaetotaxy with five sutural chaetae and four macrochaetae in Gr. II ( Figure 1E).

Thoracic chaetotaxy shown in Figure 1F. Th. II with two (m1, m2) mediomedian, three medio-lateral (m4, m4i, m4p), 16–20 posterior macrochaetae and three lateral S-chaetae. Th. III with about 26 macrochaetae and two lateral S-chaetae; m6p, m6pe and m6ai2 as macrochaetae.

Trochanteral organ with 10–15 smooth spiny chaetae; 8–11 in the arms of “L” and two to four between them ( Figure 1G). Inner differentiated tibiotarsal chaetae “smooth” with ciliations closely appressed to axis, the most distal one smooth on hind tibiotarsus ( Figure 1H); inner outstanding macrochaetae located at about onethird distance from base, ciliate and tapered at tip ( Figure 1I). Unguis with one inner distal tooth and a pair of basal slightly unequal teeth, the outer one larger. Unguiculus with a large outer tooth. Tenent hair on hind claw clavate or pointed and others pointed, subequal to unguiculus ( Figure 1J).

Abd. IV 3.9–4.6 times as long as Abd. III along dorsal midline. Abd. I with five macrochaetae centrally (m2i, m2–4, m4p) and two lateral S-chaetae. Abd. II with three central (m3, m3e, m3ep), one lateral (m5) macrochaetae and two S-chaetae; m 3ei rarely present. Abd. III with two central (a2, m3), three lateral (am6, pm6, p6) macrochaetae and two S-chaetae ( Figure 1K). Abd. IV ( Figures 1L, M) with seven central (A3–4, A6, C1, B4–6), six lateral macrochaetae and about 13 S-chaetae; anterior part of segment without S-chaetae; C1, B4 and B5 may shift anteriorly to their usual positions ( Figure 1M). Abd. V with three S-chaetae; macrochaetae m2, m3 and m5 always much larger than others ( Figure 1N). Tenaculum with 4 + 4 teeth and one large striate chaeta. Ventral tube anteriorly with seven to nine ciliate chaetae on each side ( Figure 1O); posteriorly with eight or nine smooth chaetae ( Figure 1P); each lateral flap with seven smooth chaetae ( Figures 1Q). Manubrium with 6 + 6 dorsal smooth chaetae; 1 + 1 on base of dens. Manubrial plaque with two pseudopores and three ciliate chaetae ( Figure 1R). Distal smooth part of dens subequal to mucro. Mucro falcate and basal spine long with tip reaching the apical tooth ( Figure 1S). Male genital plate not seen clearly.

Etymology

After the ancient kingdom of Lanna which covered roughly the northern part of Thailand.

Ecology

Broadleaf forest litter.

Remarks

Coecobrya lanna is closest to Coecobrya tibetensis Chen and Christiansen, 1997 in “smooth” inner differentiated tibiotarsal chaetae, claw structure, lateral process of labial palp, chaetae on labium base, chaetotaxy of Abd. I, Abd. III and lateral Abd. IV. It is also similar to Coecobrya magyari Chen, Wang and Christiansen, 2002 in “smooth” inner differentiated tibiotarsal chaetae, claw structure, lateral process of labial palp, labial chaetae, chaetotaxy of Abd. II–III, smooth chaetae on furcula and smooth chaetae on lateral flap of ventral tube. The differences among the three species are listed in Table 1.