Research Article |
Corresponding author: Barbara J. Sharanowski ( barb.sharanowski@gmail.com ) Academic editor: Andreas Köhler
© 2016 Melanie L. Scallion, Gary A.P. Gibson, Barbara J. Sharanowski.
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:
Scallion ML, Gibson GAP, Sharanowski BJ (2016) Revision of Paranastatus Masi (Eupelmidae, Eupelminae) with descriptions of four new species. ZooKeys 559: 59-79. https://doi.org/10.3897/zookeys.559.6134
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Paranastatus Masi, 1917 (Eupelmidae, Eupelminae) was originally described based on two species from Seychelles: P. egregius and P. violaceus.
Graeffea crouanii , Anastatus , South Pacific, Indian Ocean, dispersal mechanisms, biodiversity, lectotye designation, identification key
Paranastatus Masi, 1917 (Eupelmidae, Eupelminae) is one of 33 currently recognized genera within Eupelminae (
Eupelmidae is likely a grade-level taxon (
More recent collections from the South Pacific revealed new specimens of Paranastatus, including what appeared to be undescribed species. The purpose of this study was to differentiate and describe these new species and provide observations on variation observed among new P. verticalis material. An illustrated key to the world species of female Paranastatus is also included.
Type material of P. verticalis, P. nigriscutellatus, P. egregius, and P. violaceus was examined as part of a loan from The
Two systems were used to image specimens, a Nikon D5200 camera mounted on an Olympus SZX16 stereomicroscope, and a Canon DSLR 7D Mark II camera with a MP-E 65mm macro lens attached to a motorized rail. Images were taken at multiple levels of focus, and stacked into a single image using the program Helicon Focus 6 (Helicon Soft Ltd, 2014). Images were processed and enhanced using Adobe Photoshop CC 2014. Scanning electron microscope images were obtained using a Hitachi Tabletop Microscope TM-1000. Measurements were taken using a Motic SMZ-168 microscope with an Olympus G10x micrometre eyepiece. Body length was measured in millimetres a total of three times and averaged. Excluding primary types, imaged specimens are labelled with a “
Structure and sculpture terminology follows
Facial structuring can be divided into the lower face (region below toruli to clypeus and between malar sulci), scrobes (depressions rising above toruli and joining anterior to frontovertex), and interantennal area (region between scrobes and toruli). Gena refers to the region delineated by the malar sulcus and occipital margin, and extends to halfway along posterior margin of the eye. The vertex lies between the eyes from the frontovertex to the posterior margin of the eyes, where the temple begins. The temple runs between the posterior occipital margin and eyes to the genae.
Colouration of the antennomeres is often a quick identifier to species because females of four species have unique antennal colouration, though females of two species have overlapping colour patterns and two have the same colour pattern. The sculpture of the mesoscutum in combination with the extent of its concavity can be used to separate species with similar antennal colouration.
Due to the number of specimens examined, paratype and other material label data has been condensed for a few species to include localities, dates collected, and collector. A number in brackets corresponds to the number of specimens from each locality. For verbatim label data, see the Suppl. material
For a key to the world species of known Paranastatus males (P. egregius, P. nigriscutellatus, and P. verticalis), see
Note: When viewing mandible dentition, a dorsolateral view with the teeth directed forward is best for visualizing dentition (see Fig.
1 | Mandible tridentate (Fig. |
2 |
– | Mandible quadridentate (Fig. |
5 |
2(1) | Head in lateral view with vertex raised between eyes, and temple flat such that temple and occiput at almost a right angle (Fig. |
Paranastatus verticalis Eady |
– | Head in lateral view with vertex and temple slightly to distinctly convex between eyes, and temple and occiput at an obtuse angle (Figs |
3 |
3(2) | Vertex smooth posterior to ocelli towards temple. Antenna with scape blue (Fig. |
Paranastatus halko Scallion, sp. n. |
– | Vertex rugose or reticulate posterior to ocelli towards temple. Antenna mostly white except basal half of scape brown and club variable in colour. Mesoscutum reticulate (Fig. |
4 |
4(3) | Vertex rugose posterior to ocelli (Fig. |
Paranastatus bellus Scallion, sp. n. |
– | Vertex reticulate posterior to ocelli (Fig. |
Paranastatus pilosus Scallion, sp. n. |
5(1) | Temple smooth, and in dorsal view occipital margin straight. Flagellum brown except flagellomeres 7, 8 and club white. Pronotum smooth dorsally or coriaceous only along anterior edge. Mesoscutum distinctly and deeply concave posteromedially (Fig. |
6 |
– | Temple coriaceous or pustulate, and in dorsal view occipital margin concave. Flagellum variable in colour, but club brown. Pronotum coriaceous dorsally. Mesoscutum slightly concave posteromedially (Fig. |
7 |
6(5) | Head with face green to coppery-green, lower face alutaceous to coriaceous centrally (Fig. |
Paranastatus nigriscutellatus Eady |
– | Head with face dark purple-brown and entirely smooth to alutaceous. Frontovertex smooth with a few small bumps. Mesoscutum smooth, except slightly coriaceous posteromedially. Legs with all femora straw yellow. Gaster green apically, but tergites otherwise dark coppery-green and sternites brown | Paranastatus parkeri Scallion, sp. n. |
7(5) | Vertex coriaceous and dull black-brown. Flagellum with apical two funiculars light yellow-brown. Mesoscutum dark purple-brown, and mostly alutaceous except coriaceous posteromedially (Fig. |
Paranastatus violaceus Masi |
– | Vertex pustulate, purple except for coppery sheen between ocelli (Fig. |
Paranastatus egregius Masi |
1 Scanning electron micrograph (SEM) of Paranastatus halko, lower face in anterior view showing mandibular dentition (
9 Scanning electron micrograph (SEM) of Paranastatus pilosus, mesonotum in dorsal view (
15 Paranastatus verticalis holotype, lateral habitus 16 P. verticalis holotype, dorsal view 17 P. verticalis (Taveuni, Fiji), lateral habitus (
22 Paranastatus pilosus holotype, lateral habitus 23 P. nigriscutellatus holotype, lateral habitus 24 P. parkeri holotype, lateral habitus 25 P. violaceus lectotype, lateral habitus 26 P. egregius lectotype, partial body in lateral view 27 P. egregius lectotype broken body parts glued to the point.
Holotype female, dry pinned, deposited in BMNH (Hym Type 5.4813, barcode NHMUK010198566). Label data: “SULAWESI UTARA: Dumoga-Bone Nat. Pk, edge of rainforest, 0°34'N, 123°54'E. A.D. Austin June 1985, M.T.”
Paratype female, dry pinned, deposited in
Females of P. bellus are differentiated by the following combination of features: vertex rugose (Fig.
Female. Length: 2 mm.
Colour. Head with vertex dull black-brown (Fig.
Head. Vertex rugose (Fig.
Mesosoma. Pronotum coriaceous; mesoscutum reticulate, distinctly concave posteromedially; scutellar-axillar complex reticulate; mesopleuron coriaceous. Pronotum with white setae, setae longer along posterior edge; mesoscutum with many white setae; scutellar-axillar complex with few white setae along edges; mesopleuron with white setae anteriorly, remainder bare. Fore wing with dense, short brown setae; hind wing with relatively fewer short, light brown setae.
Metasoma. Entirely coriaceous with white setae ventrally, the setae very sparse dorsally and long at apex of gaster.
Male. Unknown.
From the Latin bellus, meaning handsome, in memory of Melanie Scallion’s dog Beau (French: handsome). This is an adjective in the nominative singular.
Sulawesi Island, Indonesia.
Unknown.
Holotype deposited in the BMNH at the request of Dr. Andrew Austin, University of Adelaide, Australia. Both specimens are in poor condition. The head of the holotype is glued to the point, and the paratype is contorted with the body curled up on itself.
Paranastatus egregius Masi, 1917: 165–166.
Lectotype female, here designated; dry pinned, deposited in BMNH (Hym Type 5.1,035a). Label data: “Mahe, ’08–9 Seychelles Exp. Percy Sladen Trust Exped. B.M. 1913-170.”
Paralectotype male, here designated; dry pinned, deposited in BMNH. Label data: “Mahe, ’08–9 Seychelles Exp. Percy Sladen Trust Exped. B.M. 1913-170.”
Females of P. egregius are differentiated by the following combination of features: vertex behind ocelli and temple pustulate (Fig.
Mahé Island, Seychelles.
Unknown.
Holotype female, dry pinned, deposited in
Paratype females (24), dry pinned, deposited in
(14). FIJI. Viti Levu, Vuda Prov., 1 km E Abaca Vlg., Koroyanitu Ntl. Pk, Savuione Trl. Dates collected range from 7.X.2002–6.V.2003 by E. Schlinger and M. Tokota’a.
(4, includes
(2). FIJI. Viti Levu, Naitasiri Prov., 4 km WSW Colo-i-Suva Vlg., Mt Nakobalevu, 300m. Collected 12.IV.2004 by E. Schlinger and M. Tokota’a.
(4, includes
Females of P. halko are differentiated by the following combination of features: vertex granulate between ocelli and smooth posterior to ocelli; temple smooth; scape and pedicel blue (Fig.
Female. Length: 2.6–2.95 mm.
Colour. Head with vertex dull black-brown between ocelli and metallic green changing to blue-purple posterior to ocelli towards temple; temple shining metallic blue-purple; gena and face metallic coppery-green (Figs
Head. In lateral view, vertex distinctly convex between eyes, and temple sloping toward occiput to create a strongly obtuse angle (Fig.
Mesosoma. Pronotum coriaceous; mesoscutum usually smooth, sometimes very slightly rugulose, and only slightly concave posteromedially; scutellar-axillar complex reticulate; mesopleuron coriaceous. Pronotum with few brown setae; mesoscutum with sparse light brown setae posteromedially and along margins; scutellar-axillar complex with few light brown setae; mesopleuron bare. Fore wing with dense, short brown setae; hind wing with relatively fewer short, light brown setae.
Metasoma. Entirely coriaceous; short to long brown setae evenly distributed ventrally; very sparse, short brown setae dorsally.
Male. Unknown.
Named in honour of Ed and Eliz Halko from Winnipeg, Manitoba, Canada. Their daughter, Gail Halko, also from Winnipeg, has made a donation to the Wallis-Roughley Museum of Entomology at the University of Manitoba to honour her parents, who both celebrated their 85th birthdays in 2015. This is a noun in apposition to retain integrity of the name Halko in the species name.
Viti Levu, Fiji.
Unknown.
Vertex may appear pustulate under a stereomicroscope due to the setae. Care should be taken when using antennal colouration as a guide to species since flagellomere 7 is sometimes completely brown instead of white at apex, thus resembling the antennae of P. verticalis.
Paranastatus nigriscutellatus Eady, 1956: 61–64.
Holotype female, dry pinned, deposited in BMNH (Hym Type 5.1624a). Label data: “HY 976 FIJI Savu Savu II.1954 B.A. O’Connor. Ex Graeffea crouani eggs. Com. Inst. Ent Coll. No. 13599.”
Allotype male, dry pinned, deposited in BMNH. Label data: “HY 976 FIJI Savu Savu II.1954 B.A. O’Connor. Ex Graeffea crouani eggs. Com. Inst. Ent Coll. No. 13599.”
Paratype females (6), dry pinned.
(2, deposited in BMNH). HY 975 FIJI Taveuni XI.1953 B.A. O’Connor Ex eggs of Graeffea crouani in coconut crowns.
(3, deposited in BMNH). HY 976 FIJI Savu Savu II.1954 B.A. O’Connor Ex Graeffea crouani eggs.
(1, deposited in
Females (11), dry pinned, deposited in
(5). FIJI, Viti Levu, Namosi Prov., 2 km SE Nabukavesi Vlg., Ocean Pacific Rsrt, 40m. Dates collected range from 13.III–11.XII.2003 by E. Schlinger, M. Tokota’a and W. Naisilisili.
(2, includes
(1). FIJI: Kaduva I., 0.25 km SW Solodamu Vlg., Moanakaka Bird Sanctuary, 60m. Collected 9–30.V.2003 by E. Schlinger and M. Tokota’a.
(1). FIJI: Viti Levu, Sigatoka Prov., Sigatoka Sand Dunes Nat. Pk, 44m. Collected 12.II–12.III.2003 by E. Schlinger and M. Tokota’a.
(1). FIJI: Levu Is., Maitaesiri Prov., Hakobalevu Mt, 340m. Collected 12–24.III.2003 by M. Irwin et al.
(1). FIJI: Viti Levu, Naitasiri Prov., Bakobalevu logging rd. Collected 17.III–9.IV.2003 by E. Schlinger and M. Tokota’a.
Females of P. nigriscutellatus are differentiated by the following combination of features: face alutaceous to coriaceous centrally; mandible quadridentate (Fig.
Islands of Fiji, Tonga, Western Samoa (
Parasitoids of Graeffea crouanii eggs.
Holotype female, dry pinned, deposited in
The unique female of P. parkeri is differentiated by the following combination of features: vertex and temple smooth; frontovertex smooth with a few small bumps; face smooth to alutaceous; mandible quadridentate; mesoscutum smooth except faintly coriaceous in posteromedial concavity.
Female. Length: 2.2 mm.
Colour. Head with vertex coppery between ocelli, metallic green to blue-purple posterior to ocelli; temple shining metallic green-purple dorsally to metallic blue-purple laterally; gena shining metallic coppery-green; entire face metallic dark purple-brown; frontovertex blue-green with brown centrally. Antenna with scape lightly shining green; pedicel, anellus (flagellomere 1), and flagellomeres 2–6 brown, 7, 8 and club white. Pronotum coppery-green; mesoscutum purplish-coppery, slightly bluish-green posteriorly; scutellar-axillar complex dull black; mesopleuron purple-coppery. Legs with procoxa dark brown, protrochanter light brown; mesocoxa light yellow-brown; metacoxa brown basally and white apically; remaining leg segments straw-yellow. Fore wing very lightly infuscate with hyaline band below distal half of submarginal vein; hind wing hyaline. Gaster green apically, tergites otherwise dark coppery-green and sternites brown. Colour of setae on various body regions discussed in appropriate sections below.
Head. Vertex and temple smooth; gena smooth to alutaceous along occipital margin; lower face smooth to alutaceous centrally, scrobes smooth to weakly alutaceous, interantennal area alutaceous; occipital margin straight in dorsal view; frontovertex smooth with a few small bumps. Mandible quadridentate. Entire head with sparse brown setae; eyes with sparse, very short white setae.
Mesosoma. Pronotum smooth; mesoscutum smooth to slightly coriaceous posteromedially, distinctly concave posteromedially; scutellar-axillar complex reticulate; mesopleuron coriaceous. Pronotum, mesoscutum, and scutellar-axillar complex with very few brown setae; mesopleuron with few short white setae anteriorly, remainder bares. Fore wing with dense, short brown setae; hind wing with relatively fewer short, brown setae.
Metasoma. Entirely coriaceous with long, brown setae sparsely distributed.
Male. Unknown.
Named in honour of Parker Brant, nephew of Barb Sharanowski, born November 2, 2012 in Australia to Julie and Billy Brant. This is a noun in the genitive case.
Viti Levu, Fiji.
Unknown.
Abdomen was broken and lost after description and imaging had been completed. Antennae cannot be used as an identifying character in this species because the antennal colouration is the same as that of P. nigriscutellatus.
Holotype female, dry pinned, deposited in BMNH (Hym Type 5.4814, barcode NHMUK010198567). Label data: “INDONESIA: Seram, Solea VIII.1987, MT M. Day, forest.”
Paratype females (8), dry pinned, deposited in BMNH and
(4, includes
(4). INDONESIA. Seram, Solea. VIII.1987, M. Day, forest.
Females of P. pilosus are differentiated by the following combination of features: vertex granulate between ocelli, reticulate posterior to ocelli (Fig.
Female. Length: 2.6 mm.
Colour. Head with vertex dull black-brown, sometimes purple-brown posterior to ocelli; temple dark blue-purple; gena blue-purple (Fig.
Head. Vertex granulate between ocelli, reticulate posterior to ocelli (Fig.
Mesosoma. Pronotum coriaceous (Figs
Metasoma. Entirely coriaceous with white setae evenly distributed ventrally, setae sparser and shorter dorsally, and longer at apex of gaster.
Male. Unknown.
From Latin pilosus-hairy, in reference to the females having noticeably more setae than the other species. This is an adjective in the nominative case.
Seram Island, Indonesia.
Unknown.
Paranastatus verticalis Eady, 1956: 64–65.
Holotype female, dry pinned, deposited in BMNH (Hym Type 5.1625a). Label data: “HWY 976 FIJI Suva Suva VI.1954 B.A. O’Connor. ex eggs of Graeffea crouani C.I.E.Coll. 13792.”
Allotype male, dry pinned, deposited in BMNH. Label data: “HWY 976 FIJI Suva Suva VI.1954 B.A. O’Connor. ex eggs of Graeffea crouani C.I.E.Coll. 13792.”
Paratype females (7), dry pinned.
(6, deposited in BMNH, includes
(1, deposited in
Females (2), dry pinned.
(1, deposited in
(1, deposited in
Females of P. verticalis are differentiated by the following combination of features: vertex raised between eyes, and temple flat such that temple and occiput form almost a right angle (Fig.
Islands of Fiji, Tonga, Western Samoa (
Parasitoids of Graeffea crouanii eggs.
The two specimens collected in 2004 differ in several features compared to the type series described by
Paranastatus violaceus Masi, 1917: 166–167.
Lectotype female, here designated; dry pinned, deposited in BMNH (Hym Type 5.1,036). Label data: “Silhouette, ’08. Seychelles Exp. Percy Sladen Trust Exped. B.M. 1913-170.”
Females of P. violaceus are differentiated by the following combination of features: vertex and temple coriaceous; antenna brown except flagellomeres 7 and 8 light yellow-brown (Fig.
Silhouette Island, Seychelles.
Unknown.
During the last 100 years, Paranastatus has been recorded throughout the South Pacific and from one location in the Indian Ocean (
Graeffea crouanii, the coconut stick insect, is a pest of coconut palms and is found on many islands throughout the South West Pacific, including Fiji (
The current known distribution of Paranastatus is perplexing because there are large distances between localities, which leaves the question of how the wasps dispersed through time. One hypothesis that could explain Paranastatus distribution is wind dispersal as aerial plankton. Insects have been collected far from land in both the Indian and South Pacific Ocean through aerial netting (Holzapfel and Harrel 1968), and since Paranastatus wasps are very small it is possible that they were carried across the ocean on the wind. Another hypothesis is that the wasps dispersed passively through their hosts, such as what may have occurred with parasitized Graeffea crouanii eggs (
Another possible explanation for the distribution of Paranastatus is that it was once larger than it is now. Paranastatus species are basically confined to geographical clusters: the Fijian species have not been found in Indonesia and vice versa. Paranastatusnigriscutellatus and P. verticalis have been found on several other South Pacific islands, but only east of Fiji. The two Seychelles species (P. egregius and P. violaceus) have never been found since their original capture. It may be that species of Paranastatus did exist in other regions, but have since become extinct. Extinction, if it has happened, may have occurred through habitat fragmentation that reduced the genus to its current number of species and localities. Fragmented habitats can lead to extinction by decreasing available habitat and causing smaller population sizes, and parasitoids tend to be more sensitive to habitat fragmentation than other trophic levels (
It is interesting that the newly collected female specimens of P. verticalis are darker in colour than the original specimens collected in 1954. One possibility for this is that the type specimens have faded over the course of 50 years; however, this does not seem likely as the specimens still conform to
One complication that arises when studying the taxonomy of Eupelminae is their extreme sexual dimorphism. Non-chalcidologists are likely to identify male eupelmines as Pteromalidae rather than Eupelmidae, and most identification keys to species of eupelmine genera are based only on females, which makes it difficult to correctly identify males unless they are reared together with females. There is a chance that Paranastatus males have been collected before, but were misidentified or unidentified. This may account for the lack of males recorded in this genus.
Future work on Paranastatus could include a closer examination of the biogeography of the different species. The disparate distribution between P. egregius and P. violaceus from Seychelles, and the remaining species from islands in the South Pacific, suggests that locations between these regions may have additional species of Paranastatus. Therefore, it could be worthwhile collecting in regions between Seychelles and Indonesia to improve knowledge of the distribution of the genus or to discover new species.
We would like to thank the staff of BMNH and
Paranastatus Label Data
Data type: Label data
Explanation note: This file contains complete label data for all material examined, including localities