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Research Article
Revision of Paranastatus Masi (Eupelmidae, Eupelminae) with descriptions of four new species
expand article infoMelanie L. Scallion, Gary A.P. Gibson§, Barbara J. Sharanowski
‡ University of Manitoba, Winnipeg, Canada
§ Agriculture Canada, Ottawa, Canada
Open Access

Abstract

Paranastatus Masi, 1917 (Eupelmidae, Eupelminae) was originally described based on two species from Seychelles: P. egregius and P. violaceus. Eady (1956) subsequently described P. nigriscutellatus and P. verticalis from Fiji. Here, four new species of Paranastatus are described: P. bellus Scallion, sp. n. and P. pilosus Scallion, sp. n. from Indonesia, and P. halko Scallion, sp. n. and P. parkeri Scallion, sp. n. from Fiji. A key to all Paranastatus species based on females is included and lectotypes are designated for P. egregius and P. violaceus. Finally, previously unobserved colour variation from newly collected material of P. verticalis, distribution patterns of species, and possibilities for future research are discussed.

Keywords

Graeffea crouanii, Anastatus, South Pacific, Indian Ocean, dispersal mechanisms, biodiversity, lectotye designation, identification key

Introduction

Paranastatus Masi, 1917 (Eupelmidae, Eupelminae) is one of 33 currently recognized genera within Eupelminae (Gibson 1995). This genus was initially established for two species based primarily on the distinctive triangular shape of the head of females. Four species have been described to date: P. egregius Masi, 1917 and P. violaceus Masi, 1917 from Seychelles, and P. verticalis Eady, 1956 and P. nigriscutellatus Eady, 1956 from Fiji (Masi 1917, Eady 1956). No new specimens of either P. egregius or P. violaceus have been reported since their original description and their biology remains unknown. However, O’Conner et al. (1955) and Rapp (1995) subsequently reared P. nigriscutellatus and P. verticalis from the eggs of the walking stick, Graeffea crouanii Le Guillou (Phasmatodea: Phasmatidae). Males are known only for P. egregius, P. nigriscutellatus, and P. verticalis. A key to these males was provided by Eady (1956).

Eupelmidae is likely a grade-level taxon (Gibson 1989) rather than being monophyletic (Heraty et al. 2013), though Eupelminae is supported as monophyletic (Gibson 1989). The subfamily is characterized in part by its extreme sexual dimorphism, and species and higher level taxonomy is based primarily on female morphology. Eupelmines are parasitoids or predators of eggs and primary or hyperparasitoids of other immature stages of various arthropods, including Blattaria, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Mantodea, Orthoptera and Phasmida, as well as Araneae and even Pseudoscorpionida (Gibson 1995, Austin et al. 1998). Gibson (1995) hypothesized that Paranastatus and five other genera, including Anastatus Motschulsky, formed a monophyletic clade, though with unresolved relationships and with Paranastatus possibly rendering Anastatus paraphyletic. Like known Paranastatus, members of Anastatus are mostly egg parasitoids and have been recorded as endoparasitoids of the eggs of Phasmida (Gibson 1995).

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.

Methods

Type material of P. verticalis, P. nigriscutellatus, P. egregius, and P. violaceus was examined as part of a loan from The Natural History Museum, London, England (BMNH). Paratypes of one female of P. nigriscutellatus and a male and female of P. verticalis were also examined on loan from the U.S. National Museum of Natural History, Washington, DC, USA (USNM). Other material was borrowed from the Canadian National Collection of Insects, Arachnids and Nematodes, Ottawa, ON, Canada (CNC). Some of the latter material was collected in projects requiring primary type material to be returned to the Bernice P. Bishop Museum, Honolulu, HI, USA (BPBM).

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 “JBWM Photo 2015-X” specimen number label. This is cited with other label data given for the respective specimen, in the Suppl. material 1: “Paranastatus Label Data”, and in the figure captions.

Structure and sculpture terminology follows Gibson et al. (1997), but additional clarification on sculpture terminology is provided below. Images are provided for clarity where necessary in the keys and descriptions. Alutaceous and coriaceous are similar in that they both mean leather-like (Harris 1979). Here, alutaceous refers to sculpturing where fine grooves create elongated cells, whereas coriaceous refers to sculpturing where the fine grooves create more square but irregularly-shaped cells. Coriaceous-imbricate refers to cells that appear overlapping. Reticulate refers to cells that are delineated by ridges. Pustulate refers to a bumpy texture, whereas granulate refers to many fine bumps, like granules. Rugose means wrinkled, whereas rugulose means very finely wrinkled.

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 1: “Paranastatus Label Data”. A double line, ǁ, represents a new line on the label, and ++ represents a separate label.

Taxonomy

For a key to the world species of known Paranastatus males (P. egregius, P. nigriscutellatus, and P. verticalis), see Eady (1956).

Key to world species of Paranastatus Masi based on females

Note: When viewing mandible dentition, a dorsolateral view with the teeth directed forward is best for visualizing dentition (see Fig. 3).

1 Mandible tridentate (Fig. 1). Flagellum mostly white or, if mostly brown, then flagellomere 7 entirely brown or white only apically. Lower face reticulate (Fig. 1). Gena mostly reticulate, or coriaceous to coriaceous-imbricate along occipital margin toward temple (Fig. 2) 2
Mandible quadridentate (Fig. 3). Flagellum mostly brown basally but flagellomeres 7 and 8 entirely white or light yellow-brown and sometimes flagellomere 6 white. Lower face smooth to alutaceous or coriaceous (Fig. 3). Gena alutaceous or coriaceous (Fig. 4) 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. 5). Temple smooth. Lower face with fringe of setae below toruli (Fig. 6). Flagellum brown except flagellomere 8 and club white (Figs 15, 17) 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 7, 8). Temple variably sculptured. Lower face with setae, but not arranged as a fringe (Figs 1, 3). Flagellum colour variable 3
3(2) Vertex smooth posterior to ocelli towards temple. Antenna with scape blue (Fig. 8) and flagellum brown except flagellomere 8, club, and usually apex of flagellomere 7 white (Fig. 19). Mesoscutum smooth to slightly rugulose. Gaster with tergites brown except apex of gaster green; sternites brown except white at very base 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. 9). Gaster brown except tergites 1 and 2 white; sternites variable 4
4(3) Vertex rugose posterior to ocelli (Fig. 10). Temple coriaceous and brownish-green to blue-green laterally. Gena blue-green, coriaceous to reticulate along malar sulcus. Antennal club brown. Mesoscutum purple-brown medially, straw yellow laterally, and reticulate. Fore wing hyaline behind distal half of submarginal vein, but deeply infuscate basally, lightly infuscate (tinted brown) in patch behind base of marginal vein, and infuscate from behind postmarginal vein to wing apex. Gaster brown beyond basal white sternites Paranastatus bellus Scallion, sp. n.
Vertex reticulate posterior to ocelli (Fig. 11). Temple reticulate and dark blue-purple. Gena blue-purple, reticulate. Antennal club white except slightly darkened apically. Mesoscutum blue-purple medially, brown laterally, and reticulate. Fore wing hyaline except lightly infuscate in apical half. Gaster purplish-brown beyond basal white sternites 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. 12). Fore wing infuscate with hyaline band behind distal half of submarginal vein 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. 13). Fore wing variable 7
6(5) Head with face green to coppery-green, lower face alutaceous to coriaceous centrally (Fig. 3), and interantennal area and scrobes coriaceous. Frontovertex with blunt teeth projecting towards vertex. Mesoscutum mostly alutaceous, except coriaceous posteromedially (Fig. 12). Legs with profemur black-brown except for light brown patch ventroapically, mesofemur black-brown dorsally and yellow ventrally and basally, and metafemur yellow basally and darkening to brown apically. Gaster brown except green apically, basal tergites white centrally and sternites 1–4 white 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. 13). Fore wing evenly infuscate. Gaster dark brown except apical tergites green and sternites 1 and 2 light brown Paranastatus violaceus Masi
Vertex pustulate, purple except for coppery sheen between ocelli (Fig. 14). Flagellum with apical three funiculars white. Mesoscutum light brown, and slightly coriaceous. Fore wing with hyaline band behind distal half of submarginal vein, lightly infuscate behind base of marginal vein and behind postmarginal vein, hyaline between infuscate regions and apically (Fig. 27). Gaster dark brown except tergites 1 and 2 and sternites 1–3 white Paranastatus egregius Masi
Figures 1–8.

1 Scanning electron micrograph (SEM) of Paranastatus halko, lower face in anterior view showing mandibular dentition (JBWM Photo 2015-01) 2 SEM of P. halko, gena in lateral view (JBWM Photo 2015-02) 3 P. nigriscutellatus, lower face in frontolateral view showing mandible dentition (JBWM Photo 2015-03). Inset: outline of mandible dentition showing four teeth 4 SEM of P. nigriscutellatus, head and anterior part of mesosoma in lateral view (JBWM Photo 2015-03) 5 P. verticalis, head in lateral view. Inset: outline of vertex-temple shape (JBWM Photo 2015-04) 6 P. verticalis holotype, lower face in anterior view showing fringe of setae below toruli 7 P. pilosus, head in lateral view. Inset: outline of vertex-temple shape (JBWM Photo 2015-05) 8 P. halko holotype, head in lateral view. Inset: outline of vertex-temple shape.

Figures 9–14.

9 Scanning electron micrograph (SEM) of Paranastatus pilosus, mesonotum in dorsal view (JBWM Photo 2015-05) 10 P. bellus holotype, head in dorsal view 11 SEM of P. pilosus, head and pronotum in dorsal view (JBWM Photo 2015-05) 12 P. nigriscutellatus holotype, mesonotum in dorsal view 13 P. violaceus lectotype, mesonotum in dorsal view 14 P. egregius lectotype, head in dorsal view.

Figures 15–21.

15 Paranastatus verticalis holotype, lateral habitus 16 P. verticalis holotype, dorsal view 17 P. verticalis (Taveuni, Fiji), lateral habitus (JBWM Photo 2015-06) 18 P. verticalis (Taveuni, Fiji) in dorsal view (JBWM Photo 2015-06) 19 P. halko holotype, lateral habitus 20 P. bellus holotype, head in frontolateral view and antenna 21 P. bellus holotype, body in lateral view.

Figures 22–27.

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.

Paranastatus bellus Scallion, sp. n.

Figs 10, 20, 21

Material examined

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 CNC. Label data: “INDONESIA. Sulawesi Utara, Dumoga Bone Nat. Pk, Toraut IV.1985, JS Noyes, forest edge, MT.”

Diagnosis

Females of P. bellus are differentiated by the following combination of features: vertex rugose (Fig. 10); antenna mostly white except base of scape and club brown (Fig. 20); mandible tridentate; mesoscutum purple-brown medially, straw-yellow laterally and reticulate.

Description

Female. Length: 2 mm.

Colour. Head with vertex dull black-brown (Fig. 10); temple brownish-green dorsally, blue-green laterally (Fig. 10); gena and face metallic blue-green (Fig. 20); frontovertex dull black-brown. Antenna mostly white, except base of scape and club brown (Fig. 20). Pronotum light brown; mesoscutum purple-brown medially, straw-yellow laterally; scutellar-axillar complex dark orange-brown; mesopleuron light brown to white anteriorly (Fig. 21). Legs white with mesofemur darkened along posterior apical edge and metafemur darkening to brown apically. Fore wing hyaline behind distal half of submarginal vein, but deeply infuscate basally, lightly infuscate patch behind base of marginal vein, and infuscate from behind postmarginal vein to wing apex; hind wing hyaline. Gastral tergites 1 and 2 white, remaining tergites dark brown; gastral sternites 1–4 white, remainder brown. Colour of setae on various body regions discussed in appropriate sections below.

Head. Vertex rugose (Fig. 10); temple coriaceous (Fig. 10); gena coriaceous except reticulate along malar sulcus (Fig. 20); face reticulate; frontovertex with blunt teeth projecting posteriorly towards vertex. Mandible tridentate. Vertex, temple and gena with sparse, very light brown setae; face with sparse white setae except scrobes bare; eyes with dense, short white setae.

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.

Etymology

From the Latin bellus, meaning handsome, in memory of Melanie Scallion’s dog Beau (French: handsome). This is an adjective in the nominative singular.

Distribution

Sulawesi Island, Indonesia.

Biology

Unknown.

Remarks

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

Figs 14, 26, 27

Paranastatus egregius Masi, 1917: 165–166.

Material examined

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.”

Diagnosis

Females of P. egregius are differentiated by the following combination of features: vertex behind ocelli and temple pustulate (Fig. 14); antenna brown except flagellomeres 6–8 white (Fig. 26); mandible quadridentate; mesoscutum light brown, slightly coriaceous and only slightly concave posteromedially. Males of P. egregius are differentiated by the following combination of features: vertex weakly reticulate; mandible bidentate; mesoscutum convex; colouration similar to females.

Distribution

Mahé Island, Seychelles.

Biology

Unknown.

Remarks

Masi (1917) established P. egregius based on one female and two males, but without designating a holotype. Of the three specimens, the BMNH only has the female and one of the males in its collection (Dale-Skey, pers. comm.). Here we designate the female as lectotype and the male as paralectotype, and have labelled the specimens accordingly. The location of the second male is presently unknown.

Paranastatus halko Scallion, sp. n.

Figs 1, 2, 8, 19

Material examined

Holotype female, dry pinned, deposited in BPBM (Type No. 17540). Label data: “FIJI: Viti Levu, Vuda Prov., Koroyanitu Pk, 1 km E Abaca Vlg., Savuione Trl, 800m, 22.IV–6.V.03 Malaise 1, Schlinger, Tokota’a. 17.667°S, 177.55°E. FBA 180165.”

Paratype females (24), dry pinned, deposited in BPBM and CNC. Collecting data for all specimens examined are listed below. However, date ranges are provided when multiple specimens were collected from the same locality with the full label data for each specimen listed in Suppl. material 1: “Paranastatus Label Data”.

(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 JBWM Photo 2015-02). FIJI. Viti Levu, Vuda Prov., 0.5 km N Abaca Vlg., Koroyanitu Eco Pk, Mt Evan’s Range. Dates collected range from 26.X–3.XII.2002 by E. Schlinger and M. Tokota’a.

(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 JBWM Photo 2015-01). FIJI. Viti Levu, Naitasiri Prov., 4 km WSW Colo-i-Suva Vlg., Mt Nakobalevu, 372m. Dates collected range from 25.II–14.XI.2003 by E. Schlinger and M. Tokota’a.

Diagnosis

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. 8); mandible tridentate (Fig. 1); mesoscutum smooth or very slightly rugulose.

Description

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 8, 19); frontovertex usually brown, sometimes blue-green with brown centrally (5/25 specimens). Antenna with scape and pedicel blue (Fig. 8), anellus (flagellomere 1) and flagellomeres 2–6 brown, tip of 7 usually white but sometimes brown, 8 and club all white (Fig. 19). Pronotum metallic blue-purple dorsally, coppery-green laterally; mesoscutum reddish-brown to more orange-brown; scutellar-axillar complex dull black; mesopleuron brown. Legs with procoxa light yellow-brown although sometimes dark brown (3/25 specimens), protrochanter dark brown, sometimes light yellow-brown (8/25), and profemur dark black-brown, sometimes with light spot apically on ventral surface (1/25); mesocoxa light yellow-brown, mesotrochanter light brown, mesofemur black-brown dorsally with a lighter streak ventrally, and mesotibia white; metacoxa white, sometimes with brown spot basoventrally (1/25), metatrochanter light brown, sometimes white (2/25), and metafemora dark black-brown; remaining tibiae and tarsomeres light yellow-brown to straw-yellow. Fore wing infuscate with hyaline band behind distal half of submarginal vein; hind wing hyaline. Gastral tergites brown, apex of gaster green; sternites brown except white at very base. Colour of setae on various body regions discussed in appropriate sections below.

Head. In lateral view, vertex distinctly convex between eyes, and temple sloping toward occiput to create a strongly obtuse angle (Fig. 8); vertex granulate between ocelli and smooth posterior to ocelli, sometimes appearing pustulate due to setae; temple smooth; gena coriaceous-imbricate to reticulate along malar sulcus (Figs 2, 8); face reticulate; frontovertex usually with blunt teeth projecting posteriorly towards vertex. Mandible tridentate, possibly appearing quadridentate in some views due to slight bump on ventral edge of large middle tooth (Fig. 1). Vertex and temple with evenly dispersed light brown setae; gena with brown setae, but with a patch of thick white setae on upper part of gena below eye; parascrobal region and region between toruli and clypeus with thick white setae; eye with short white setae; face otherwise with thinner brown setae.

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.

Etymology

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.

Distribution

Viti Levu, Fiji.

Biology

Unknown.

Remarks

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

Figs 3, 4, 12, 23

Paranastatus nigriscutellatus Eady, 1956: 61–64.

Material examined

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 USNM). HY 975 FIJI Taveuni XI.1953 B.A. O’Connor Ex eggs of Graeffea crouani in coconut crowns.

Other material

Females (11), dry pinned, deposited in BPBM and CNC. Collecting data for all specimens examined are listed below. However, date ranges are provided when multiple specimens were collected from the same locality with the full label data for each specimen listed in Suppl. material 1: “Paranastatus Label Data”.

(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 JBWM Photo 2015-03). FIJI: Viti Levu, Vuda Prov., Koroyanitu Pk, 1 km E Abaca Vlg., SavuioneTrl, 800m. 22.IV–6.V.2003 by E. Schlinger and M. Tokota’a.

(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.

Diagnosis

Females of P. nigriscutellatus are differentiated by the following combination of features: face alutaceous to coriaceous centrally; mandible quadridentate (Fig. 3); pronotum smooth dorsally (sometimes coriaceous along anterior margin), alutaceous laterally; mesoscutum purplish-coppery, slightly bluish-green posteriorly, alutaceous to coriaceous posteromedially, distinctly concave posteromedially (Fig. 12). Males of P. nigriscutellatus are differentiated by the following combination of features: head entirely coriaceous; mandible quadridentate; scutellar-axillar complex coriaceous; colouration darker than that of females.

Distribution

Islands of Fiji, Tonga, Western Samoa (Noyes 2015).

Biology

Parasitoids of Graeffea crouanii eggs.

Paranastatus parkeri Scallion, sp. n.

Fig. 24

Material examined

Holotype female, dry pinned, deposited in BPBM (Type No. 17541). Label data: “FIJI: Viti Levu, 3.5 km N Veisari Stlmt, logging rd to Waivudawa, 14.II–8.III.03, 300m, Malaise 3, coll. E. Schlinger, M. Tokota’a 18.068°S, 178.367°E. FBA 136331.”

Diagnosis

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.

Description

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.

Etymology

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.

Distribution

Viti Levu, Fiji.

Biology

Unknown.

Remarks

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.

Paranastatus pilosus Scallion, sp. n.

Figs 7, 9, 11, 22

Material examined

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 CNC.

(4, includes JBWM Photo 2015-05). INDONESIA. Seram, Solea. IX.1987, M. Day.

(4). INDONESIA. Seram, Solea. VIII.1987, M. Day, forest.

Diagnosis

Females of P. pilosus are differentiated by the following combination of features: vertex granulate between ocelli, reticulate posterior to ocelli (Fig. 11); temple reticulate (Fig. 11); antenna mostly white except scape brown basally and club lightly darkened apically (Fig. 22); mandible tridentate; mesoscutum blue-purple medially, brown laterally, and reticulate (Fig. 9).

Description

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. 7); lower face mostly blue-purple but brown centrally below toruli; scrobes and interantennal area green or coppery-green; frontovertex dull black-brown or with blue centrally. Antenna white, except basal half of scape brown and very tip of club slightly darkened, and sometimes club completely white (Fig. 22). Pronotum metallic purple-blue, sometimes purple-brown laterally; mesoscutum blue-purple medially, brown laterally; scutellar-axillar complex dull black; mesopleuron purple. Legs with profemur white; mesofemur white with darkened posterior apical edge; metafemur white becoming yellow-brown apically; rest of legs white. Fore wing lightly infuscate in apical half, hyaline in basal half with small infuscate patch at base; hind wing hyaline. Gastral tergites 1–2 white, rest dark brown; gastral sternites 1–4 white, remainder purplish-brown. Colour of setae on various body regions discussed in appropriate sections below.

Head. Vertex granulate between ocelli, reticulate posterior to ocelli (Fig. 11); temple reticulate (Fig. 11); gena and face reticulate; occipital margin concave in dorsal view; frontovertex with blunt teeth projecting posteriorly towards vertex or sometimes granulate. Mandible tridentate. Head with white setae except scrobes bare; eyes with dense, short white setae.

Mesosoma. Pronotum coriaceous (Figs 9, 11); mesoscutum reticulate, distinctly concave posteromedially (Fig. 9); scutellar-axillar complex reticulate (Fig. 9); mesopleuron coriaceous. Pronotum with white setae, setae longer along posterior edge; mesoscutum with dense white setae; scutellar-axillar complex with few long white setae; mesopleuron with few 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 evenly distributed ventrally, setae sparser and shorter dorsally, and longer at apex of gaster.

Male. Unknown.

Etymology

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.

Distribution

Seram Island, Indonesia.

Biology

Unknown.

Paranastatus verticalis Eady, 1956

Figs 5, 6, 15–18

Paranastatus verticalis Eady, 1956: 64–65.

Material examined

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 JBWM Photo 2015-04). HY 976 FIJI Suva Suva VI.1954.

(1, deposited in USNM). HY 976 FIJI Suva Suva VI.1954 B.A. O’Connor.

Other material

Females (2), dry pinned.

(1, deposited in BPBM). FIJI. Taveuni, Cakaudrove Prov., 5.5 km SE Tavuki Vlg., Devo Pk. 1188m, 30.VI–14.VIII.2004 Malaise 1, Schlinger, M. Tokota’a. 16.843°S, 179.966°W. FBA 152624. JBWM Photo 2015-06.

(1, deposited in CNC). FIJI. Vanua Levu, Bua Prov., 6 km NW Kilaka, 15.VI–24.VI.2004 Batiqere Range. Malaise. 98m ǁ Schlinger, Tokota’a FJVN58b_M05_07 _16.8067, 178.9914 FBA174462.

Diagnosis

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. 5); vertex granulate; lower face with fringe of setae below toruli (Fig. 6); mandible tridentate; mesoscutum smooth and convex or flat, not concave (Fig. 16). Males of P. verticalis are differentiated by the following combination of features: vertex granulate; mandible tridentate; in dorsal view occipital margin deeply excavate; colouration darker than that of females.

Distribution

Islands of Fiji, Tonga, Western Samoa (Noyes 2015).

Biology

Parasitoids of Graeffea crouanii eggs.

Variation

The two specimens collected in 2004 differ in several features compared to the type series described by Eady (1956). The specimen from Taveuni Island has a body length of 2.85 mm, whereas all specimens in the type series range from 2.4–2.5mm. Unfortunately, an accurate measurement of body length was not possible in the specimen from Vanua Levu because the body is contorted. The scutellar-axillar complex in the new material is dark black-brown (Fig. 18) not light orange-brown (Fig. 16), and the legs are darker than in the type series (Fig. 17). Other slight variations in colour include: temple green-purple laterally, not blue-purple; lower face metallic blue-green, not coppery-green; and pronotum purple-blue dorsally, not purple-coppery. The new material has gastral tergite 1 white, tergite 6 light orange-brown, and remaining tergites dark brown, not gastral tergite 1 white and remaining tergites light brown, or gastral tergite 1 white, tergites 2 and 3 dark brown, and remaining tergites grading to light brown at gastral apex.

Paranastatus violaceus Masi, 1917

Figs 13, 25

Paranastatus violaceus Masi, 1917: 166–167.

Material examined

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.”

Diagnosis

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. 25); mandible quadridentate; fore wing evenly infuscate (Fig. 25). Males unknown.

Distribution

Silhouette Island, Seychelles.

Biology

Unknown.

Remarks

Masi (1917) established P. violaceus based on three females, one of which was stated as lacking its gaster. Of the three females, the BMNH only has one complete specimen in its collection (Dale-Skey, pers. comm.). We here designate this female as lectotype and have labelled it accordingly. The location of the other two females is presently unknown.

Discussion

During the last 100 years, Paranastatus has been recorded throughout the South Pacific and from one location in the Indian Ocean (Masi 1917, Eady 1956, Rapp 1995, O’Connor 1955). Paranastatus egregius and P. violaceus were described from Seychelles and additional specimens have not been reported since. This may be because these two species are extremely rare, now extinct, or most likely collecting efforts have been insufficient to recover them. Differentiating between these possible reasons would require more intensive sampling of biodiversity, an issue that is important worldwide because of climate change, habitat destruction, and species extinctions. Paranastatus nigriscutellatus and P. verticalis have been recorded subsequent to their description, mostly from the islands of Fiji, but also from Tonga (Rapp 1995) and only through rearing rather than collecting. Most of the new material described here was obtained through passive collecting by Malaise traps. This and other passive collecting methods may provide the best way to obtain specimens of Paranastatus other than through rearing.

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 (Deesh et al. 2013). Deesh et al. (2013) hypothesized that G. crouanii dispersed in one of three ways: (1) by eggs that fell into canoes from overhanging palms on the beach; (2) by eggs floating across the ocean to other islands because they are saline-tolerant; or (3) simply by the adults being carried on coconut leaves by humans to new locations. The dispersal of eggs of G. crouanii could account for the dispersal of P. verticalis and P. nigriscutellatus, suggesting that wherever this stick insect is found, these two species of Paranastatus could be found as well.

Gibson (1995) proposed a hypothesis to explain dispersal ability of females in Eupelminae. Because of structural modifications to improve jumping ability, females appear to have reduced flight capabilities that reduce their ability to disperse. He used this hypothesis to explain why better known eupelmine species often have several to numerous hosts, it being advantageous to develop on a wide array of hosts within a limited dispersal area for survival of the parasitoid population. This suggests that species of Paranastatus could have a wider host range than is currently recorded.

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 (Deesh et al. 2013). If other hosts are discovered similar dispersal mechanisms might also be discovered. It is also possible that the true distribution of this genus has yet to be discovered. Because two of the new species as well as P. nigriscutellatus and P. verticalis are from Fiji, and the other two new species are from Indonesia, it is conceivable that more species of Paranastatus exist in other regions of the South Pacific and Indian Ocean.

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. Paranastatus nigriscutellatus 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 (Kruess and Tscharntke 2000).

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 Eady’s (1956) description. The two newly collected specimens of P. verticalis are from localities east and west of the original type locality. The slightly more western specimen is from Bua province on Vanua Levu, whereas the eastern specimen is from Cakaudrove province, Taveuni Island. The type specimens were from Savusavu, Vanua Levu, which is centered between Bua province and Taveuni Island. It is possible that continual colour variation would be found across the entire distribution of this species, if sampled, or that females vary in colour pattern based on a specific niche, host, environment or some other difference affecting development.

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.

Acknowledgments

We would like to thank the staff of BMNH and USNM for lending us type material of all previously described species. Dr. Erwin Huebner, Andre Dufresne, Leanne Peixoto, and Derek Eyer were all greatly appreciated for their help in obtaining scanning electron microscope images. We would also like to thank Amber Bass and Jordan Bannerman for their help with wasp photo shoots, and Miles Zhang for offering lots of support and ideas through the course of this research project as well as patiently putting up with all sorts of questions from MLS. We are also grateful to the two reviewers for their valuable comments. This research was funded by the NSERC Discovery program from a grant awarded to BJS and a NSERC Undergraduate Student Research Award to MLS.

References

  • Austin AD, Gibson GAP, Harvey MS (1998) Synopsis of Australian Calymmochilus Masi (Hymenoptera: Eupelmidae), description of a new Western Australian species associated with a pseudoscorpion, and review of pseudoscorpion parasites. Journal of Natural History 32(3): 329–350. doi: 10.1080/00222939800770171
  • Deesh AD, Swamy BN, Khan MGM (2013) Distribution of coconut stick insect, Graeffea crouanii and its parasitoids in selected islands of Fiji. Fiji Agriculture Journal 53(1): 18–24.
  • Eady RD (1956) Two new species of the genus Paranastatus Masi (Hym. Eupelmidae) from Fiji. Bulletin of Entomological Research 47(1): 61–67. doi: 10.1017/S0007485300046514
  • Gibson GAP (1989) Phylogeny and classification of Eupelmidae, with a revision of the world genera of Calosotinae and Metapelmatinae (Hymenoptera: Chalcidoidea). Memoirs of the Entomological Society of Canada 121(S149): 3–121. doi: 10.4039/entm121149fv
  • Gibson GAP (1995) Parasitic wasps of the subfamily Eupelminae: Classification and revision of world genera (Hymenoptera: Chalcidoidea: Eupelmidae). Memoirs on Entomology, International 5: 1–421.
  • Gibson GAP, Huber JT, Woolley JB (1997) Annotated Keys to the Genera of Nearctic Chalcidoidea (Hymenoptera). NRC Research Press, Ottawa, Canada, 794 pp.
  • Harris RA (1979) A glossary of surface sculpturing. Occasional Papers in Entomology 28: 1–31.
  • Heraty JM, Burks RA, Cruaud A, Gibson GAP, Liljeblad J, Munro J, Rasplus J-Y, Delvare G, Janšta P, Gumovsky A, Huber J, Woolley JB, Krogmann L, Heydon S, Polaszek A, Schmidt S, Darling DC, Gates MW, Mottern J, Murray E, Dal Molin A, Triapitsyn S, Baur H, Pinto JD, van Noort S, George J, Yoder M (2013) A phylogenetic analysis of the megadiverse Chalcidoidea (Hymenoptera). Cladistics 29(5): 466–542. doi: 10.1111/cla.12006
  • Holzapfel EP, Harrell JC (1968) Transoceanic dispersal studies of insects. Pacific Insects 10(1): 115–153.
  • Kruess A, Tscharntke T (2000) Species richness and parasitism in a fragmented landscape: experiments and field studies with insects on Vicia sepium. Oecologia 122(1): 129–137. doi: 10.1007/PL00008829
  • Masi L (1917) Chalcididae of the Seychelles Islands. Novitates Zoologicae 24: 121–230.
  • O’Connor BA, Pillai JS, Singh SR (1955) Notes on the coconut stick insect, Graeffea crouani Le Guillou. Fiji Agriculture Journal 25: 89–92.
  • Rapp G (1995) Eggs of the stick insect Graeffea crouanii Le Guillou (Orthoptera, Phasmidae). Mortality after exposure to natural enemies and high temperature. Journal of Applied Entomology 119(1–5): 89–91. doi: 10.1111/j.1439-0418.1995.tb01249.x