Macao elegant flat wasp: a new species insect

from Macau






A New Insect Species of the First Recorded Genus Eleganesia from Macau

(Eleganesia macavensis Ng et al., 2022. sp. nova., Bethylidae, Hymenoptera, Insecta)


Owen et E. Ng

L  Cognitio Sapiens Ngensis, Acta Scientrium Ngensis,
  email address:  hongkongensis@gmail.com

20th January, 2022



Acta Scientrium Ngensis was founded on Macau, Macaology studying  is our righteousness. Index Pteridoflora hongkongense et macaoense was included in the updated checklist species of ferns of Hong Kong & Macau (2007), after our investigation project of pteridology of Macau. In 2011, the Geological Survey for the entire territory of Macau (geographical boundaries of the Portuguese Era) was carried out, we summarized our researching and published our special topic in geology of Macao, Aetas Geologica Macaoense.

Until recently, this new wingless flat wasp species is only found in Colina de Ilha Verde, Macau, and decided to investigate this area and wish to have some new finding, we believe that this is undoubtedly beneficial for insect investigation, so we decided to do some our own small, and this is also the authors wish!


Key words:
Colina de Ilha Verde, MACAU,  Eleganesia, a genus new to Macau, Subfamily: Pristocerinae, Family: Bethylidae,  Eleganesia macavensis Ng et al., 2022., sp.nov.


Considerable Methodology of collecting:
Eleganesia is subterranean wasp and rarely found due to their cryptic habitat, They may be found in litter soil near ground level, In general, there are three collecting methods:
Wrinkle extractor - Soil samples are collected from habitat area, placing in the inner net bag then covered with outer bag which the collecting bottle with water is attached to the hole, hanging up for 7 ~ 15 days, waiting the tiny creatures drops from the soil bag into collecting bottle.
(2) Subterranean traps, this method seems to be not suitable for this species.
(3) Hand Collecting, directly but depends on probability, although it's not the best way, the female caste is collected by this way.

Living specimen of female (Eleganesia macavensis Ng et al., 2022., sp. nov.),  06th Oct., 2018.




● Class: Insecta
● Subclass: Pterygota
● Superorder: Endopterygota
● Order: Hymenoptera
● Family: Bethylidae
● Subfamily: Pristocerinae
● Genus: Eleganesia Alencar et Azevedo, 2018
Macao elegant flat wasp Eleganesia macavensis Ng et al., 2022., sp.nov.

Typical thoracal structure of the genus Eleganesia[2] (Redrawn by Owen)

Based on the scarcity of the references for classification of  this subfamily, we can only identified the Macau specimen as an unknown species in the genus Apenesia. In fact, the morphological characteristics of head, thorax, abdomen structure and size ratio are quite fit for this genus. However, no updated references about the genus Eleganesia were applied to the regions of  Macao and adjacent areas until the second half of 2021. The latest data shows that the properties of some species in the genus Apenesia have been revised, so that the specimens collected in Macao can also be reviewed. After  a seials of careful comparison, it shows that its thoracic structure (see the figure) is more similar to that of the genus Eleganesia (2018), and is more distantly related to the genus Apenesia, many species of the genus Apenesia found in Taiwan or Ryukyu have been revised as within the genus Eleganesia. Therefore, we decided to classify this specimens collected from Colina de Ilha Verde, Macau in 2018 as a new species of the genus Eleganesia.


Eleganesia macavensis Ng et al., 2022., sp.nov. (Drawn by Owen)
At: Apical tooth of mandible, Ma: Mandible (a. upper view, b. lower view), Pro: Propodeum,  Scut: Scutellum / Mesoscutellum, Prop: Metapectal propodeal complex

NGIN-731154 Type specimen of the new species

I. Dorsal view; II. Side view;  III. Ventral view

● Description of various parts of Eleganesia macavensis Ng et al., 2022., sp. nov. female

Ac: Antennal club,   Ap: Acidopore,   Cly: Clypeus,   Co: Coxa,   Fe: Femur,   Es: Eyespot,   Fl: Flagellum,   Ga: Gaster,   Ma: Mandible,  Meso: Mesoscutum;  
Oc: Occiput,   Pet: Petiole,   Pro: Propodeum,   Prop: Metapectal propodeal complex,   Py: Pygidium,   Sc: Scape,   Scut: Scutellum / Mesoscutellum,  
Se: Stemite,   T: Tibia,   Tc: Tarsal claw,   Te: Tergite;   Ts: Tarsus
Measurings: (Values or "l=" are indicate in length, TL: Total length "w=" width, "h=" hight, "d=" diameter)

The real time video record of the discovery of this new species in Colina de Ilha Verde, Macau, 06th Oct., 2018.

Etymology: This tiny new species is named after its locality, Macav, the ancient Portuguese name of Macau, and no suitable Chinese translation name for this new genus, so the author suggests to add the descriptive Chinese name, it means "Elegant ant-like wasp" (Elegant flat wasp).
Specimen ID: NGIN-713154, Tyrus, female,
Identification record: cf. Apenesia sp. 'Macaunica' Ng et al., 2018 (unpublished)

Locality: Colina de Ilha Verde, MACAU,  alt. 55m
Geographic coordinates: ca.22°12'43"N, ca.113°32'17"E,
Climate condition: 27°C, Sunny / Clear, Date of collected: 06 X 2018,
Method of Collecting: Hand selection.
Preservation State: Natural death in the feeding tube, persevered by 80% ethanol-glycerol buffered mixture solution,
Depository: Acta Scientrium Ngensis (Natural History Section), HONG KONG.

Sampling and discovering the new species from the site  (the cave has been refilled and restored to its original state after done)

Habitat: Highly weathered Granito de Macau / Macau Granite (Jmo), forms a black soil rich in humus, loose texture, the following small organisms has been easily found under Wrinkle extractor method: Campodea staphylinus Westwood, 1842, Campodeidae,  Monomorium pharaonis (L.), 1758, Formicidae, Brachyponera obscurans (Walker), 1859, Formicidae, Meristolohmannia macaoensis Ermilov, 2018, Lohmanniidae, Scheloribates praeincisus (Berlese), 1910, Scheloribatidae, Dimiodiogalumna ilhaverdeensis Ermilov, 2018, Galumnidae, Epidamaeus sp., Damaeidae & tiny geophilomorpha

I. Head

Antenna: Sc:0.15mm, Fl: 0.36mm, Ac:0.15mm,  Head: (l=0.51mm, w=0.28mm, h=0.21mm),  Ma: (l=0.18mm,w=0.05mm); Es: d=0.02(0.017)mm, Neck: (w=0.09mm)

II. Thorax & Petiole:

Frontal leg: Co: 0.13mm, Fe:0.18mm, Ts: 0.22mm, Ts: ca.0.08mm, Mesosoma: TL=0.78mm: Pro: (L=0.22mm, h=0.25mm), Scut: (l=0.25mm, h=0.24mm) Prop: (l=0.20mm; h=0.19mm), Pet: (l=0.07mm, w= ca. 0.04mm)

III. Gaster


TL=1.1mm, h (max.)=0.40mm, Se IV: h=0.38, Se V: (h=0.35mm), Se VI: (h=0.31mm),  Se VII:( h=0.25mm) Ap: (w=0.06mm)

This new species differs from other known species in that the apical tooth of mandible (At) is significantly longer, and are very pointed, and the exoskeleton is less chitinized, so the whole body is translucent amber. scutellum / mesoscutellum (Scut) is wider with ridges at the top, and metapectal propodeal complex (Prop) is larger and wider than other known species.

Total Length: 2.1mm, antennal club to scape: 0.6mm, 12 flagella segments, Length of head: 0.4mm, wide: 0.2mm, mesosoma (D): 0.6mm, gaster (G): 1.1mm, redish brown color /  amber color (living specimen), the size for naked eye is clearly recognize, with eyespots (Es), Pronotum, Scutellum and metathoracic plates are clearly differentiated, gaster enlargement, the speed of movement in the soil is slow, was found alone in the underground about 10 cm under the soil.



In early 2019, the author has consulted two entomology professors from Hong Kong and Japan on the this sole specimen, Dr. Benoit Guénard from the School of Biological Sciences, University of Hong Kong has pointed out that it belongs to Bethylidae and not formicidae, and  Professor Mamoru Terayama from the Department of Biology, University of Tokyo presumed that bethylid wasp female may belong to the genus Eleganesia or Epynesia and both are not known in female during 2019, due to insufficient reference materials and none of new specimens to be found for advanced researching, the project can only be put on hold. The confirmation of this species for the genus is also based on a paper on the revision of the known species of Eleganesia found in Taiwan and the Ryukyu Islands [2].

The author hereby expresses great respect to Dr. Benoit Guénard & Professor Mamoru Terayama, and is deeply grateful for their valuable academic insights!


[1] C. O. Azevedo, I. D. C. Alencar, M. S. Ramos, D. N. Barbosa, W. D. Colombo, J. M. Vargas, and J. Lim. 2018. Global guide of the flat wasps (Hymenoptera, Bethylidae). Zootaxa 4489:1-294
[2] Hauchuan Liao, Mamoru Terayama, Katsuyuki Eguchi, Revision of Taiwanese and Ryukyuan species of Eleganesia Alencar & Azevedo, 2018 (Hymenoptera, Bethylidae), Zoologischer Anzeiger, Volume 294, 2021, Pages 62-79.
[3] I. D. Alencar,  Sistemática de Apenesia: abrindo a caixa de Pandora dos Pristocerinae, 13 January 2017, Doutorado em Biologia Animal.



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