Review Article |
Corresponding author: John T. Huber ( john.huber2@agr.gc.ca ) Academic editor: Michael S. Engel
© 2015 John T. Huber, Serguei Triapitsyn.
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:
Huber JT, Triapitsyn S (2015) Redescription of Chrysoctonus and description of Chrysoctonoides (Hymenoptera, Mymaridae), a new genus from the Australian Region. ZooKeys 505: 79-101. https://doi.org/10.3897/zookeys.505.9472
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Chrysoctonoides longisetosa Huber & Triapitsyn (Hymenoptera: Mymaridae), gen. n. and sp. n., is described from Australia. It is compared with the related genus Chrysoctonus, known from Africa and the New World. Myrmecomymar Yoshimoto, syn. n., is synonymized under Chrysoctonus Mathot and its type species is transferred to Chrysoctonus as C. masneri (Yoshimoto), comb. n.
Australia, Chrysoctonus, Myrmecomymar, redescription
The type specimens and about 85 specimens of Myrmecomymar masneri Yoshimoto, 30 unidentified specimens (several species) of the genus from Canada and USA, and 55 specimens from Central and South America were examined, from Belize and the Dominican Republic in the north to Uruguay in the south. The holotype of Chrysoctonus apterus Mathot and several additional specimens from central Africa were also examined. Abbreviations used are: fl =funicle segment (in female) or flagellar segment (in male), gt = gastral tergum, LOL = least ocellar length (i.e., shortest distance between anterior and a posterior ocellus), mps = multiporous plate sensillum, OOL = ocular-ocellar length (i.e., shortest distance between posterior ocellus and eye), POL = posterior ocellar length (i.e., shortest distance between posterior ocelli). The term “fenestra”, used below in the descriptions, was defined and illustrated for Mymaridae in
ANIC Australian National Insect Collection, Canberra, ACT, Australia.
CAS California Academy of Sciences, San Francisco, California, USA.
CNC Canadian National Collection of Insects, Arachnids and Nematodes, Ottawa, Ontario, Canada.
IRSNB Institut Royale des Sciences Naturelles de Belgique, Brussels, Belgium.
UCRC University of California, Riverside, California, USA.
Photographs were taken with a ProgRes™ C14plus digital camera attached to a microscope, and the resulting layers combined electronically using Syncroscopy Auto-Montage™ and, except for primary types, retouched as needed with Adobe™ Photoshop. Micrographs of gold-coated specimens were taken with a Phillips scanning electron microscope.
Chrysoctonus Mathot, 1966: 224. Type species: C. apterus Mathot. Type locality: Democratic Republic of the Congo, Yangambi, 0°46'N, 24°27'E, in forest litter.
Myrmecomymar Yoshimoto, 1990: 28. Type species: M. masneri Yoshimoto. Type locality: Canada, Ontario, Spencerville. Syn. n.
Female. Body length 425–890. Wingless (Figs
Male. Body length 425–760. Fully winged. Head (Figs
The greatest range in number of funicle segments of any genus of Mymaridae is found in Chrysoctonus species: one specimen from Panama had 4 segments and two from Costa Rica had 8 segments; the usual number appears to be 5 segments.
The only described species in Myrmecomymar is transferred here to Chrysoctonus as C. masneri (Yoshimoto), comb. n.
Hosts are unknown. Specimens from the type locality were collected in August in pan traps placed near the base of trees in a forest normally flooded in spring and early summer (L. Masner, personal communication). Other specimens of the type species and other, undescribed, species were collected in Canada from a sedge pond, hollows and hummocks in a bog, peat bog, old forest, Carya grove, and spring flood debris. In the USA specimens have been collected from a hardwood forest, beaver swamp, oak forest, and forest hammock. In Central and South America and various Caribbean islands specimens were collected from wet cloud forest litter, forest litter, compost pile, forested creek, montane oak forest, cloud forest, rainforest, palm forest, and thicket forest, from about sea level to 2000m. The habitat types strongly suggest that females parasitize hosts found in moist soil or associated with water. The holotype of C. apterus and other African specimens were collected from forest litter.
Western Hemisphere and Afrotropical Region. Specimens have been seen from 22 countries in the New World, from southern Canada to northern Argentina and Uruguay, and 4 countries in central Africa.
Chrysoctonus apterus Mathot, 1966: 225 (description). Holotype female (IRSNB), on slide (Fig.
Female. Body length 495–561 (n=8). Funicle 7-segmented, with 2 mps on fl4, fl6, and fl7, and 1 mps on fl5. Vertex uniformly covered with short setae arising at interstices of reticulate sculpture, and anteromedially with a distinct cluster of short setae in a circular area (Fig.
Male. Body (Fig.
One female from Gabon, collected 29.ii.2000, has a one antenna with the funicle 6-segmented (fl3 absent) and another female collected on the same day has one funicle with fl4 and fl5 fused.
CENTRAL AFRICAN REPUBLIC. Sangha-Mbaéré: Parc National Dzanga-Ndoki, 39.6 km 174°S of Lidjombo, 340 m, 2°21'03"N, 16°08'50"E, 20–28.v.2001, B. L. Fisher, sifted litter in rainforest, seasonally flooded riparian, CAS/BLF4146 (3 ♀, CAS, UCRC). GABON. Ogooue-Maritime: Mont Doudou, 24.3 km 307°NW Doussala, 375 m, 2°13'21"S, 10°24'21"E, 29.ii.2000, B. L. Fisher, sifted litter in rainforest, CAS/BLF2122 (6 ♀, CAS, CNC, UCRC); Réserve de Faune de la Moukalaba-Dou 12.2 km 305°NW Doussala, 110 m, 2°17°00"S, 10°29'49"E, 24.ii.2000, B. L. Fisher, sifting, litter in rainforest, CAS/BLF2170 (1 ♀, CAS). DEMOCRATIC REPUBLIC OF THE CONGO. Pool: Lesio-Louna Reserve, Iboubikro site, 340 m, 3°16.196'S, 15°28.267'E, 23.vii.2008, M. Sharkey, Y. Braet (1 ♂, UCRC).
Chrysoctonus masneri Yoshimoto, 1990: 84 (description). Holotype female (CNC), examined.
(length and width, except length only for flagellar segments): scape 148/28, pedicel 59/27, fl1 87, fl2 98, fl3 98, fl4 97, fl5 98, fl6 96, fl7 102, fl8 98, fl9 102, fl10 100, fl11 97; fl6 length/width 5.09; total flagellum length 1072. Wing measurements: fore wing length/width 795/152, longest marginal setae 216; hind wing length/width 494/11, longest marginal setae 126.
Myrmecomymar:
Chrysoctonoides longisetosa Huber & Triapitsyn.
After the genus Chrysoctonus + eidos, Greek for shape, form, resembling, like; referring to the similarity of females and males to those of Chrysoctonus. Gender: feminine.
Female. Wingless (Figs
Male. Fully winged (Fig.
Chrysoctonoides longisetosa, paratype female and paratype male from Lake Eacham Nat. Park. 58 female antenna 59 female mesosoma (crushed), dorsal 60 male mesosoma, dorsal 61 fore leg 62 male wings 63 female metasoma, lateral 64 male antennal cleaner 65 male genitalia 66 male antenna. Scale bars: 58–61, 63 = 50 µm; 62, 66 = 100 µm; 64, 65 = 20 µm.
Chrysoctonoides differs from Chrysoctonus, the most similar-looking genus, as follows. Female: mesoscutum and scutellum each medially much longer than pronotum (each about the same length in Chrysoctonus); median and lateral lobes of mesoscutum, and scutellum with strong setae (setae absent in Chrysoctonus); fenestra small, somewhat triangular and occupying much less than half width of scutellum (fenestra large, oval, occupying most of scutellum in Chrysoctonus). Male: Flagellum with each segment somewhat irregular-shaped, often slightly wider medially and with at most only 1 mps and 4 setae, the setae much longer than segment length (each segment with straight edges and parallel-sided, with several mps and setae, the setae much shorter than segment length in Chrysoctonus). Both sexes: prosternum large, about as long as line of junction of propleura (small, much shorter than line of junction in Chrysoctonus).
Female. Medium in length and wingless in the only included species. Head. Almost cuboidal, about 1.25× as wide as long and about 1.2× as wide as high; in lateral view projecting forward for about length of radicle beyond level of anterior margin of eye then, more ventrally, flat and receding to mouth (Figs
Male. Medium in length and fully winged (Fig.
Hosts are unknown. The habitat is rainforest litter.
Australian Region.
(ANIC) on slide, labelled: 1. “17.37S 145.34E, QLD BS3 Massey Creek, 1000m, 30 May–1 July 1996, P. Zborowski, 1000m, FI Trap JCU”. 2. “Chrysoctonoides longisetae ♀ Huber & Triapitsyn HOLOTYPE”.
4 ♀ and 2 ♂. AUSTRALIA. Queensland: Atherton, 17.17°S, 145.29°E, 2–16.iii.1988, D.C.F. Rentz, stop A-1, flight intercept trap (1♀, ANIC); Heberton, 30.xii.97–5.i.1998, A. Zwick, rainforest (1♂, CNC); Lake Eacham National Park, 17.17°S, 145.37°E, 760m, 3–7.xi.1976, R.W. Taylor & T.A. Weir (1♀, 1♂, ANIC); Massey Creek, 17.37°S, 145.34°E, 1000m, 3.x–2.xi.1995, L. Umback (1♀, ANIC); 11 km ENE of Mt. Tozer, 12.43°S, 143.18°E, 11-16.vii.1986, T. Weir, rainforest litter, Berlese, 1063 (1♀, ANIC).
AMERICAN SAMOA. Tutuila Island, Mapusaga, 20–27.i.2002, M. Schmaedick, YPT on forest floor (1 ♂, UCRC).
This male is not given paratype status because its specific identity is uncertain. Conspecific females from American Samoa must be collected and compared with the Australian females to determine if they are the same.
From Latin, longus, meaning long, and setosa, meaning bristly, referring to the long setae on the flagellum of the male and the mesosoma of the female. The name is treated as a noun in apposition.
Female. Body length 570–675 (n=2). Colour. Yellow; brown are trabecula, sockets of setae on mesosoma, and, especially, propodeum, and gaster dorsally and laterally in about apical half but anterior to cerci. Head. Width 174 (n=1). Vertex with two pairs of fairly short setae, eye orbit dorsally with three long setae, one posteriorly and two anteriorly. Antenna. Fl1 the shortest segment (Figs
Male. Body length 535 µm (n=1). Flagellar segments with uneven edges and varying widths, apparently with 1 mps on each segment; fl11 distinctly narrower than fl10. Measurements of length/width (n=1): scape length/width 138/23, pedicel 50/25, fl1 25/13, fl2 55/13, fl3 60/13, fl4 53/18, fl5 55/13, fl6 58/15, fl7 55/18, fl8 63/25, fl9 43/25, fl10 43/23, fl11 43/10; total flagellum length about 350; flagellomeres each with a whorl of 4 setae usually at least twice length of segment.
Chrysoctonoides and Chrysoctonus may be sister genera though there are still considerable structural differences between them, especially in the mesosoma. Features that suggest a sister group relationship are: females apterous whereas males macropterous, wing shape in males identical, with long venation, antennal (especially funicle) and gastral structure in females very similar.
We thank J. Read and K. Bolte (Natural Resources Canada, Ottawa), the senior author’s technicians (retired), for preparing the photographs and micrographs, respectively, except for figures 48 and 49 prepared by R. Burks (UCRC, Riverside, California) and figures 23, 25, 27, and 30 prepared by the junior author. J. Cardale (ANIC, Canberra) is thanked for the loan of specimens of Chrysoctonoides (unidentified at the time) to the senior author. P. Groetaart (IRSNB, Brussels) is thanked for the loan of the holotype of Chrysoctonus apterus.