New cave-dwelling species of Tomoceridae from China, with a study on the pattern of mesothoracic bothriotricha in Tomocerinae (Collembola, Entomobryomorpha).
ABSTRACT: Two new troglobitic species of Tomoceridae are described from Guizhou and Guangxi provinces, China. Tomocerus tiani sp. n. resembles Tomocerus kinoshitai Yosii, 1954, Tomocerus caecus Yu & Deharveng, 2015 and Tomocerus similis Chen & Ma, 1997 but differs from them mainly in the body colour, the cephalic chaetotaxy and the number of manubrial pseudopores. Monodontocerus cinereus sp. n. is similar to Monodontocerus mulunensis Yu, Deharveng & Zhang, 2014 but is different from the latter in the body colour, the length of antennae, the number of ungual teeth and the chaetotaxy on Abd. III and Abd. IV. Special remarks are made on the mesothoracic bothriotricha in Tomocerinae.
Project description:The Tullbergiidae of Tibet is studied for the first time and the genus Metaphorura Bagnall, 1936 is firstly recorded in China. Metaphorura motuoensissp. n. from southeastern Tibet is described and illustrated. It is characterized by the presence of 1+1 pseudocelli on thoracic segment I, few vesicles (14 -16) on PAO, pseudocellar formula as 11/111/11111, all pseudocelli of type II, setae p4 on abdominal segment V as microsetae, weakly differentiated sensory seta p3 on abdominal segment V, absence of median process on Abd VI. In addition, Mesaphorura yosii (Rusek, 1967), Mesaphorura hylophila Rusek, 1982, and Prabhergia imadatei Tamura & Zhao, 1996 are recorded in Tibet for the first time. The type specimens of P. imadatei are re-examined and errors in the original description of chaetotaxy are corrected.
Project description:The paper considers new and little-known species of the genus Tetracanthella distributed in the Far East of Russia and in Japan. Sensillar chaetotaxy and labial palp, two less known morphological characters for the genus, are discussed. Two new species T.annulata sp. nov. and T.tardoki sp. nov. are described; T.manschurica Kutyreva, 1980 and T czernovae Kutyreva, 1980 are redescribed. For the latter species a lectotype and paralectotypes are designated. Remarks are provided for T.sylvatica Yosii, 1939. A second undescribed species is recorded for Japan. New records for T.orientalis Martynova, 1977 and T.sibirica Deharveng, 1987 are listed.
Project description:A new species, Dicranocentrus hainanicus Ren & Zhang, sp. n., is described from Hainan Province, China. Complete tergal chaetotaxy including microchaetae is illustrated and discussed. It is characterized by having the dental spines arranged in 2-3 rows, two inner teeth on unguis, 5, 2, 2 central macrochaetae on Abd. I-III, two inner S-chaetae on Abd. V displaced anteriorly, and the additional microchaetae associated with the S-chaeta acc.p6 on Th. II-Abd. II. It is most similar to D. chenae Ma, Chen & Soto-Adames but differs from the latter in the number and arrangement of dental spines and the absence of macrochaeta Pa1 on dorsal head. A key to the Chinese species of the genus is provided.
Project description:Two new blind species of Sinella are described from Nanjing, China. Sinella quinseta sp. n. from Purple Mountain possesses unique 5+5 central macrochaetae on Abd. II, and can be distinguished from other species of the genus by the postlabial chaetae and the dorsal chaetotaxy. Sinella qixiaensis sp. n. from Qixia Mountain is characterized by the paddle-like S-chaetae of Ant. III organ and the smooth straight chaetae on the manubrium and base of dens; it differs from two closely related species by the smooth manubrial chaetae, the labial chaetae, the Ant. III organ, and the macrochaetae on Abd. II. Sinella fuyanensis Chen & Christiansen and Sinella quinocula Chen & Christiansen were also newly recorded from Nanjing.
Project description:A third species of the genus Sinhomidia is described from South China: S. uniseta sp. nov. This new species can be distinguished from the two other species of the genus by the following characters: colour pattern, single labial chaeta M, chaetotaxy on terga and ventral tube, unguis with three inner teeth, and 15 clypeal ciliated chaetae. Also, the chaetotaxy of the first instar of Sinhomidia is described for the first time in the present paper, and confirms the close relationship between Sinhomidia and Homidia. A key to species of Sinhomidia is provided.
Project description:The first Tomocerus species with a postantennal organ (PAO) in the adult stage is described from Vietnam. Tomocerus postantennalis sp. n. differs from the other PAO-possessing tomocerid, Tomolonus reductus Mills, 1948, mainly in the morphology of PAO, the number of ocelli, the number of chaetae in trochantero-femoral organ and several features of the furca. The new species is placed in Tomocerus because of the presence of a toothlet on the outer basal mucronal tooth and the absence of the diagnostic character states of Plutomurus Yosii, 1956 and Aphaenomurus Yosii, 1956. Besides the presence of PAO, the new species is peculiar in having six prelabral chaetae, instead of four as in other Tomocerus species. The new species is similar to Tomocerus folsomi Denis, 1929 and Tomocerus ocreatus Denis, 1948 in the type of dental spines but different from them in the body colour, the relative length of antennae to body, the number of unguis inner teeth and the number of mucronal intermediate teeth.
Project description:Two new species of Neanurinae (Collembola) are described from the Western Cape, South Africa: Ectonura monochaetasp. n. and Ectonura barraisp. n.Ectonura monochaetasp. n. differs from other species in the genus by its strongly reduced chaetotaxy, and the lateral shift of dorso-internal chaetae on Abd. V and their integration in the tubercles (De+DL). Ectonura barraisp. n. is similar to Ectonura natalensis (Womersley, 1934), but differs in chaetotaxic details and chaetal group arrangement. A key to the seven species of Neanurinae recorded from South Africa is given.
Project description:Dicranocentrus liuae sp. n. is described from the northern subtropical region of China. The new species is most similar to D. wangi Ma & Chen, 2007, but differs from it in the relatively shorter Ant. V, the 1+1 central macrochaetae on Abd. III, the number of chaetae on tenaculum, and the absence of dental spines. The systematic position of Dicranocentrus is also discussed. Present evidence, particularly S-chaetotaxy, indicates that the genus is closer to Heteromurus than to the unscaled species of Orchesella and Orchesellides.
Project description:The genus Acrocrytus is reported from Chinese mainland for the first time, with description of two new species Acrocyrtus zhujiensis sp. n. and Acrocyrtus finis sp. n. from Zhejiang Province, East China. They can be separated from other species of this genus by colour pattern, unscaled appendages (antennae, legs and ventral tube), interocular chaetae, labial basal chaetae, bothriotrichal complex chaetae on Abd. II-IV, microchaeta a2 on Abd. II, im on Abd. III and C1p on Abd. IV. Illustrations and a table showing main differences with closest Acrocyrtus species are provided.
Project description:Insect colour is extremely diverse and produced by a large number of pigmentary and nanostructural mechanisms. Considerable research has been dedicated to these optical mechanisms, with most of it focused on chromatic colours, such as blues and greens, and less on achromatic colours like white and gold. Moreover, studies on the evolution of these colours are less common and largely limited to inferences from extant organisms, in part because of the limited amount and types of available fossil material. Here, we directly compare nanostructure and colour of extant and amber-preserved (approx. 15 and 99 Myr old, respectively) gold-coloured representatives of micromoths (Lepidoptera: Micropterigidae) and springtails (Collembola: Tomoceridae). Using electron microscopy, microspectrophotometry and finite domain time difference optical modelling, we show that golden coloration in the extant micromoth is produced by nanometre-scale crossribs that function as zero-order diffraction gratings and in the springtail by a diffraction grating without crossribs. Surprisingly, nanostructure and thus predicted colour of the amber-preserved specimens were nearly identical to those of their extant counterparts. Removal of amber enabled direct colour measurement of the fossil micromoth and further revealed that its colour matched both that of the extant specimen and the predicted colour, providing further support for our optical models. Our data thus clearly show an early origin and striking conservation of scale nanostructures and golden coloration, suggesting strong selection pressure either on the colour itself or on the mechanisms that produce the colour. Furthermore, we show the thus-far untapped potential for the use of amber-preserved specimens in studies on the evolution of organismal coloration.