Research Article |
Corresponding author: Mei-Ying Lin ( linmeiying2021@126.com ) Academic editor: Lyubomir Penev
© 2015 Wen-Xuan Bi, Chang-Chin Chen, Mei-Ying Lin.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Bi W-X, Chen C-C, Lin M-Y (2015) New record of Jacobsoniidae (Coleoptera) from China with description of a new species of Sarothrias Grouvelle. ZooKeys 496: 53-60. https://doi.org/10.3897/zookeys.496.8620
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The family Jacobsoniidae Heller (短跗甲科) is newly recorded from China upon the discovery of Sarothrias sinicus Bi & Chen, sp. n. (中华短跗甲) from Motuo, Southeast Xizang. Description and illustrations of the habitus and major diagnostic features of the new taxon are provided. A key to the species of Sarothrias and some ecological notes on the new species are presented.
Jacobsoniidae , Sarothrias , new record, new species, taxonomy, Oriental region
The family Jacobsoniidae Heller, 1926 was considered incertae sedis within the series Bostrichiformia by
Jacobsoniidae includes 21 known species in three genera: Sarothrias Grouvelle, 1918, Saphophagus Sharp, 1886 and Derolathrus Sharp in Sharp & Scott, 1908 (
Currently, 13 species of Sarothrias have been described (
During July to August 2014, the first author participated in an expedition to Motuo (=Mêdog), Xizang, the third time that he visited that area. A small but remarkable beetle collected during this expedition represented an interesting, unexpected result in that it is an undescribed species of Sarothrias which belongs to the Jacobsoniidae – a family so far not recorded from China. In this paper, we describe a new species, Sarothrias sinicus Bi & Chen, sp. n., based on this specimen. An identification key to the species of Sarothrias is also included. Based on
Holotype: male, “China: Xizang, Motuo / Baricun / 2014.VII.27 1850 m / leg. Wen-Xuan Bi” [white label printed]. The holotype was deposited in the Insect Collection of Shanghai Normal University, Shanghai, China (SNUC).
This new species can be separated from most congeners by the elytra, which are predominantly shiny, and elytral row 5 unimpressed; the pronotum is devoid of squamiform setae. It differs from S. hygrophilus Pal by the elytra, with row 1 largely represented by fine punctures, row 2 interrupted by punctures after basal quarter, and with supplementary series (s1) between rows 3 and 4; the pronotum has secretions on the lateral margins instead of on the side below the protrusions. It also resembles S. papuanus Ślipiński but can be easily distinguished by the elytra, bearing four squamiform setae in the distal half of row 2, row 3 merging with row 2 and with s1 between rows 3 and 4; the pronotum is devoid of secretions.
Male (Figs
Head broader than long, width across eyes 0.45 mm, clypeus smooth, rounded anteriorly, fronto-clypeal suture clearly visible; frons slightly broad anteriorly with sides moderately raised, sparsely and distinctly setigerous punctured; eyes large, rounded, nearly as long as half of head length, coarsely facetted. Antenna length 0.88 mm, scape slightly elongate, antennomeres 2–11 transverse, with secretions on antennomeres 1–8, squamiform setae at apex of scape and on antennomeres 2–10 and normal setae on antennomeres 9–11.
Pronotum length 0.67 mm, width 0.48 mm, subparallel-sided, widest near middle; anterior margin rounded; disc with a shallow median groove, extending from the anterior one-fifth to little above base, slightly broad posteriorly; punctures on disc of similar size, shape and distribution to those on head; median groove, lateral margins and one-sixth of pronotal base with secretions. Scutellum invisible.
Elytra length 1.38 mm, width 0.79 mm, fusiform, widest slightly after middle; basal transverse bulge well developed, with subbasal band of secretions on which three subbasal depressions on each elytron, each depression with one squamiform setae posteriorly. Each elytron with striae or fine puncture forming 8 rows and 3 supplementary series (Fig.
Prosternum and mesoventrite largely covered with secretions. Metaventrite covered with the same secretions after mesocoxal insertions (cavities) and between metacoxal insertions, other parts shiny with very sparser and fine punctures; with deep median impression in apical half which with rounded sides and not delimited by lateral ridges. Legs moderately long, tarsi 3-segmented.
Adult Sarothrias have been collected in leaf litter and rotten wood, but the larvae are as yet unknown (
China: Xizang (Tibet) Autonomous Region, Motuo County.
The new species is named after the country of the type locality.
(modified from
1 | Elytra entirely mat and covered by secretions, except a narrow shiny stripe along the suture and which is devoid of secretions | 2 |
– | Elytra partly shiny, not completely covered by secretions | 6 |
2 | Terminal antennomere with a whorl of squamiform setae as on antennomeres 2 to 10 | 3 |
– | Terminal antennomere devoid of a whorl of squamiform setae | 4 |
3 | Sides of pronotum with 2–3 squamiform setae; antennomere 2 twice as long as antennomere 3. Sabah | S. crowsoni Löbl & Burckhardt, 1988 |
– | Sides of pronotum devoid of setae; antennomere 2 about 1.4× as long as antennomere 3. Moluccas | S. audax Ślipiński & Löbl, 1995 |
4 | Epipleural keel of elytra extending more towards base than lateral keel | 5 |
– | Epipleural and lateral keels of elytra ending at about the same level. New Britain | S. boumei Ślipiński, 1986 |
5 | Median depression of metaventrite indistinctly delimited, narrowing towards apex beyond middle; mat, covered by secretions. Seychelles | S. eximius Grouvelle, 1918 |
– | Median depression on metaventrite well delimited laterally, gradually narrowing towards apex; apical portion shiny, devoid of secretions. Fiji | S. fijianus Löbl & Burckhardt, 1988 |
6 | Secretions on head and pronotum strongly expanded, those on elytra forming longitudinal stripes which are separated by shiny stripes. South India | S. indicus Dajoz, 1978 |
– | Dorsal surface of body predominantly shiny; pattern formed by secretions on elytra different | 7 |
7 | Pronotum with 2–3 squamiform setae on sides | 8 |
– | Pronotum devoid of squamiform setae | 9 |
8 | Elytral secretions forming apical drop-shaped loop; antennomere 11 with squamiform setae. Sumatra | S. dimerus (Heller, 1926) |
– | Elytral secretions strongly reduced; antennomere 11 without squamiform setae. New Caledonia | S. pacificus Ślipiński & Löbl, 1995 |
9 | Elytron with row 5 entirely deeply impressed, merged. with row 4 apically. Queensland | S. lawrencei Löbl & Burckhardt, 1988 |
– | Elytron with row 5 at most impressed near base and then continued as separate punctures, not joined with row 4 | 10 |
10 | Elytron with rows 1 and 3 impressed only at base and then continued as a row of separate punctures | 11 |
– | Elytron with rows 1 and 3 well impressed, row 3 with impression at least surpassing middle of elytron | 12 |
11 | Elytron with row 2 presented two squamiform setae apically, disconnected with row 3; devoid of s1. Papua New Guinea | S. papuanus Ślipiński, 1986 |
– | Elytron with row 2 presented four squamiform setae after middle, connected with row 3; with s1 between rows 3 and 4 (Fig. |
S. sinicus sp. n. |
12 | Rows 2 and 3 of elytron entirely impressed, join far before level of metacoxae and at level of last puncture of row 5. Malaysia | S. amabilis Ślipiński & Löbl, 1995 |
– | Rows 2 and 3 of elytron join near the level of metacoxae or behind it, further below level of last puncture of row 5, row 3 completely or incompletely impressed | 13 |
13 | Row 3 of elytron entirely impressed before joining with row 2. New Guinea | S. morokanus Poggi, 1991 |
– | Row 3 of elytron impressed but interrupted just before joining with row 2, where it is represented by separate punctures. Northeast India | S. hygrophilus Pal, 1998 |
We wish to express our heartfelt thanks to Adam Ślipiński (Australian National Insect Collection, Canberra, Australia) for providing us with pertinent literature, improving the earlier draft of this paper and for his continuous encouragement, to Richard Leschen (New Zealand Arthropod Collection, Auckland, New Zealand) and another anonymous reviewer for critical comments, and to Jennifer Hammock (Smithsonian Institute, National Museum of Natural History, Washington, USA) for improving the English. Chao Wu (Beijing, China) and Xiao-Dong Yang (Sichuan, China) provided great companionship to the first author during the Xizang expedition. We are very grateful to Hong-Liang Shi (Beijing, China), Gan-Yan Yang (Beijing, China) and Xiao-Bin Song (Shanghai, China) for their passion for collecting little-known beetles and for sharing their knowledge. Special thanks are due to a Chinese entomology forum “http://insect-fans.com/bbs/forum.php”, which provided a communication platform for amateurs for more than ten years.