Biodiversity Data Journal :
Single Taxon Treatment
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Corresponding author: Filippo Di Giovanni (aphelocheirus@gmail.com)
Academic editor: Francisco Javier Peris Felipo
Received: 16 Apr 2021 | Accepted: 05 May 2021 | Published: 28 May 2021
© 2021 Filippo Di Giovanni, Diego Pádua, Rodrigo Araujo, Alvaro Santos, Ilari Sääksjärvi
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:
Di Giovanni F, Pádua DG, Araujo RO, Santos AD, Sääksjärvi IE (2021) A striking new species of Dolichomitus Smith, 1877 (Hymenoptera: Ichneumonidae; Pimplinae) from South America. Biodiversity Data Journal 9: e67438. https://doi.org/10.3897/BDJ.9.e67438
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Dolichomitus Smith, 1877 is a genus of Darwin wasps characterised by their large bodies and long ovipositors, that includes more than 75 species worldwide, 20 of which occur in the Neotropical Region. Due to recent efforts, the number of species of this genus continues to increase in South America.
A new iridescent species of Pimplinae, Dolichomitus meii sp. nov., is described and illustrated. It was discovered from the biological station of Yanayacu located in the north-eastern slopes of the tropical Andes. It may be separated from all other species of Dolichomitus Smith by the striking colour pattern and apically strongly decurved ovipositor.
Darwin wasps, Ephialtini, idiobiont, iridescence, parasitoid, cloud forests, rain forest, Amazonia, Andes, Neotropics, tropical
Dolichomitus Smith is a widespread genus of pimpline Darwin wasps, represented in the Neotropical Region by 20 described species (
Structurally, Dolichomitus rather closely resembles Anastelgis Townes and Umanella Gauld in South America. All three genera contain moderately large species with long ovipositors and strong oblique grooves cutting off triangular areas on the anterolateral corners of the second metasomal tergite. Dolichomitus may be easily separated from Anastelgis by the set of the following characters: 1) apex of upper ovipositor valve simple, without tiny denticles (with a row of small denticles in Anastelgis), 2) lower valve of ovipositor laterally expanded to partially enclose the upper valve (lower valve not expanded in Anastelgis) and 3) mid-coxae of males often with prominences which are separated by deep concavities (coxae simple in Anastelgis). Umanella, on the other hand, with only three known species (
The Central American species of Dolichomitus may be identified with the key provided by
The aim of the present study is to describe a striking new species of Dolichomitus from the tropical Ecuadorian Andes. In our opinion, the species is amongst the most spectacular tropical Dolichomitus ever described.
Morphological terminology follows
Holotype, female (Fig.
Head. Face about 0.7 times as high as wide, smooth and shiny, with small and setiferous punctures, distance between punctures greater than their diameter; compound eye slightly convergent ventrally (Fig.
Mesosoma. Pronotum smooth and shiny, impunctate; epomia small (Fig.
Metasoma. Metasoma smooth and shiny, impunctate, only last tergites with barely discernible setiferous punctures (Fig.
Colour. Head, including clypeus and mandible, black, with blue reflections; palps brownish-black with last segment yellowish-brown at the proximal 0.75; antenna, scapus and pedicel black. Mesosoma, including scutellum, postscutellum, tegula and propodeum black with blue reflections. Fore wing yellowish with a distal darkened area that covers the fourth submarginal cell almost entirely; hind wing yellowish; veins and pterostigma orange. All coxae, trochanters and trochantelli black with bluish reflections, inner distal margin of all trochantelli yellowish-brown; fore femur black with bluish reflections, with a yellow line on outer surface running from proximal 0.75 to the apex; mid-femur black with blue reflections, with a yellow spot on outer side at apex; fore and mid-tibiae yellow, fore and mid-tarsi with segments yellow to gradually darker distally, last segment brown; hind femur entirely black with blue reflections, hind tibia and tarsus dull black. Metasoma with tergites I–V orange, tergite II orange with two small black spots on posterior margin just near hind corners, tergites VI+ bluish-black. Ovipositor sheath black.
Dolichomitus meii sp. nov. can be distinguished from the other Neotropical species of the genus by the combination of the following characteristics: 1) body length ca. 22.0 mm, 2) bluish-black head, mesosoma and metasomal tip, with orange metasomal tergites I–V, 3) wings yellowish with distal darkened area, 4) ovipositor sheath length ca. 4.70× as long as hind tibia and 5) ovipositor tip strongly decurved, with subapical dorsal lobe of lower valves not delimited posteriorly, but gradually developing into the apical teeth, dorsal lobe with an anterior groove reclivous, followed by three ridges, the first two almost vertical and the third inclivous.
The specific epithet is in honour of Maurizio Mei, a great entomologist and dear friend of FDG.
Ecuador
Host unknown. Both type specimens have been collected approximately at the same altitude (2000 m a.s.l.).
Dolichomitus meii sp. nov. resembles D. orejuelai Araujo & Pádua, 2020 in colour pattern, with body partly dark and metasomal tergites I-V predominantly orange, but it differs from the latter in having mesosoma entirely black with blue reflections (mesosoma mostly reddish-black with red marks in D. orejuelai), metasomal tergite I and III–V entirely orange and metasomal tergite II orange with two small black spots on posterior margin just near hind corners (metasomal tergites yellowish-brown with posterior margins of tergites II–V reddish-black in D. orejuelai) and wings yellowish-orange with distal darkened area (wings yellowish, but without distal darkened area in D. orejuelai). In case of the wing colouration, D. meii sp. nov. keys out with D. pimmi Araujo & Pádua, 2020 in the updated key to the South American species of the genus, but it can be distinguished from the latter in having mesosoma entirely black with blue reflections and metasomal tergites I–V orange (mesosoma and metasoma yellow with black marks in D. pimmi).
Unknown.
Updated key to the South American species of Dolichomitus Smith, 1877 (adapted from Araujo et al. 2020) Step 6 of the key, provided by |
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6 | Fore wing iridescent or hyaline or yellowish, but always with apex black. | 7 |
– | Fore wing entirely yellowish or yellowish with anterior margin more strongly yellowish. | 9 |
7 | Fore wing hyaline or iridescent. | 8a |
– | Fore wing yellowish. | 8b |
8 | Malar space 0.55× as long as proximal mandibular width; head mostly black; fore wing iridescent with strongly contrasting distal darkened area that at least covers completely the fourth submarginal cell and third discal cell, pterostigma black; metasoma mostly black shining. | D. menai Araujo & Pádua |
– | Malar space 0.30× as long as proximal mandibular width; head mostly yellow; fore wing hyaline with strongly contrasting distal darkened area that covers only the distal half of fourth submarginal cell, pterostigma dark brown; metasoma mostly yellowish with black lateral spots and anterior dorsal longitudinal stripe on tergite I. | D. mariajosae Araujo & Pádua |
9 | Mesosoma yellow with black marks; metasoma mostly orange yellow with anterior half of tergite I, posterior half of tergite V, tergites VI–VII and posterior margin of tergite VIII yellow, lateral spots and an anterior dorsal longitudinal stripe on tergite I, posterior margin of tergites I–IV, tergite VIII black and anterior margin of tergites VI and VII with a dark brown spot dorsally. | D. pimmi Araujo & Pádua |
– | Mesosoma black, with blue reflections; metasomal tergites I–V orange, tergite II orange with two small black spots on posterior margin just near hind corners, tergites VI+ bluish-black. | D. meii Di Giovanni & Sääksjärvi, sp. nov. |
Almost nothing is known about the biology of tropical American Dolichomitus. The ovipositor tip of D. meii sp. nov. is very strongly decurved; as suggested by
The conspicuous colouration of the species, with head and mesosoma shiny black with blue reflections, golden yellow wings with dark distal area and orange metasoma (with only the last tergites black), is unique. Many large-sized and metallic Darwin wasps are known to occur in South America (mainly Cryptinae and Ichneumoninae). However, within the tropical American species of the subfamily Pimplinae, the metallic blue colouration was previously only known in the genera Pimpla Fabricius and Umanella. To our knowledge, D. meii sp. nov. is the only metallic species of Dolichomitus. In case of D. meii sp. nov., the metallic blue colouration (reflections) of head and mesosoma is clearly visible when observing the specimens under a light source. However, it may be difficult to observe in nature.
With the description of this remarkable species, we hope to draw attention to the largely unknown, yet seemingly diverse, Darwin wasp fauna of the tropical Andes. It is obvious that our understanding of the tropical Andean Darwin wasps is incomplete. Future field studies will likely require us to re-define the current understanding of the diversity patterns of the family.
We are indebited to Dr Pierfilippo Cerretti and Maurizio Mei ("Sapienza", University of Rome, Italy) for the material collected in Ecuador and preserved in the entomological collections of “Sapienza”, University of Rome (MZUR). We are deeply grateful to the Ministry of Environment of Ecuador (referent Dr D. Inclán) for providing the collecting permits. The paratype female was collected by Carol Castillo who did her MSc thesis in the University of Turku (Finland) on diversity of Andean ichneumonids under the supervision of IES. We would like to thank Carol for allowing us to use it in the description of D. meii sp. nov. Carol has discovered many highly interesting new species of tropical Andean ichneumonids during her expeditions in the Andes – including, for example, the first record of the subfamily Acaenitinae from South America. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES – Finance Code 001 (DG Pádua), (88887.302820/2018-00, AD Santos)). Finally, we are grateful to Dr Francisco Javier Peris-Felipo (University of Valencia, Spain), Dr Gavin Broad (Natural History Museum, London, UK), Dr Oleksandr Varga (Schmalhausen Institute of Zoology, Kyiv, Ukraine) and one anonymous referee for valuable comments on the manuscript.
FDG and IES determined and described the new species; DGP and ROA updated the taxonomic key for the Neotropical species of Dolichomitus adding the new species; ADS contributed with the insertion of the new species in the identification key, besides having produced and edited the figures available in this study. All authors participated in the writing of the text of this manuscript.