Research Article |
Corresponding author: John T. Huber ( john.huber2@agr.gc.ca ) Academic editor: Petr Janšta
© 2017 John T. Huber.
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 (2017) Eustochomorpha Girault, Neotriadomerus gen. n., and Proarescon gen. n. (Hymenoptera, Mymaridae), early extant lineages in evolution of the family. Journal of Hymenoptera Research 57: 1-87. https://doi.org/10.3897/jhr.57.12892
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Eustochomorpha Girault, with one described species, E. haeckeli Girault, from Australia is redescribed. Neotriadomerus Huber, gen. n., is described, together with seven new species, all from Australia: N. burwelli Huber, sp. n., N. crassus Huber, sp. n., N. darlingi Huber, sp. n., N. gloriosus Huber, sp. n., N. longiovipositor Huber, sp. n., N. longissimus Huber, sp. n. (one of the largest species of Mymaridae), and N. powerae Huber, sp. n. Proarescon Huber, gen. n., is described for P. primitivum (Huber), comb. n., transferred from Borneomymar Huber, and P. similis Huber, sp. n., from Thailand. The previously unknown male of Borneomymar madagascar Huber is described and the genus is redescribed from critical point dried and slide mounted specimens. Triadomerini, stat. n., is proposed to include six genera: Borneomymar, Eustochomorpha and Neotriadomerus, and the Cretaceous Carpenteriana Yoshimoto, Macalpinia Yoshimoto and Triadomerus Yoshimoto. Aresconini is proposed to include five (possibly six) genera: Arescon Enock, Kikiki Huber and Beardsley, Proarescon Huber and Tinkerbella Huber and Noyes, and the Cretaceous Myanmymar Huber and, tentatively, also Enneagmus Yoshimoto. The two tribes are proposed as being the earliest lineages in Mymaridae, with Neotriadomerus and Triadomerus being sister genera to the remaining extant and extinct genera, respectively.
Taxonomy, Chalcidoidea , fairyfly, new genera, Australia, Thailand, earliest lineages
Eustochomorpha Girault (Hymenoptera: Mymaridae) includes a single species, E. haeckeli Girault (
This study is based on about 35 specimens on card-mounts, point-mounts and slides. Slides of the specimens were prepared as described in
Eustochomorpha haeckeli Girault, by monotypy.
Female. Antenna with funicle 8-segmented and clava 2-segmented (Figs
Female. Body ≈1280–1290 μm in length, excluding section of ovipositor exserted beyond apex of hypopygium. Colour. Generally brown (Fig.
Male. Unknown.
Hosts are unknown. The holotype was collected in forest (
Eustochomorpha
haeckeli
Holotype female (
Female. Among extant genera, E. haeckeli is distinguished from the first new genus described below, having a 2-segmented clava (3-segmented in the first new genus), and the ovipositor strongly exserted posteriorly beyond apex of gaster and not extending anteriorly under the mesosoma. It differs from the second new genus described below by the postmarginal vein shorter than the marginal vein (postmarginal vein longer than marginal vein in the second new genus), hypochaeta absent (hypochaeta present in the second new genus), and it differs from Borneomymar by its 2-segmented clava (1-segmented in Borneomymar).
Eustochomorpha haeckeli, female. 11 head + prothorax, lateral 12 head + prothorax, dorsal 13 base of antenna, lateral (right antenna) and ventral (left antenna) 14 apex of antenna 15 mesosoma, dorsal 16 mesosoma, posterolaterodorsal 17 mesosoma, lateral 18 base of wings + mesosoma, lateral (medial portion). Scale bar for 11, 12, 16 = 50 μm; 13, 14, 18 = 20 μm; 15, 17 = 100 μm.
Eustochomorpha haeckeli, female. 19 wings 20a parastigma, ventral 20b base of marginal vein, ventral 20c apex of marginal vein, stigma + postmarginal vein, ventral 21a parastigma, dorsal 21b stigma, dorsal 22 gaster apex showing cerci, posterolaterodorsal 23 gaster apex showing cerci, dorsal 24 gaster apex, posterolaterodorsal. Scale bar for 19 = 200 μm; 20a, 20b, 21b, 22–24 = 20 μm; 20c, 21a = 50 μm.
Eustochomorpha haeckeli, female. 25 gaster apex, lateral 26 ovipositor apex, dorsal 27 ovipositor apex, ventral 28 ovipositor + sheaths, lateral 29 apex of ovipositor + sheaths, lateral 30 ovipositor + sheaths, dorsal 31 apex of sheaths (one sheath folded over on itself). Scale bar for 25 = 50 μm; 26, 27 = 5 μm; 28, 30 = 100 μm; 29, 31 = 20 μm.
Female. Body length ≈1280 (critical point dried specimen, Stirling Range National Park). Colour. Body mainly brown (Fig.
Male. Unknown.
Two females, collected in Malaise traps in combination with yellow pan traps underneath. AUSTRALIA. Western Australia: Yanchep National Park, 20–21.xii.1986, J.S. Noyes (1♀ on slide,
Eustochomorpha
:
Neotriadomerus longiovipositor Huber, by present designation.
Female. Antenna with funicle 8-segmented and clava 3-segmented (Figs
Female. Body 1380–5500 in length, excluding basal sac of gaster (enclosing anterior extension of ovipositor). Colour. Generally brown (Figs
Male. Similar to female. Body 1280–2560 in length (males still unknown for the largest species). Flagellum with 11 relatively wide segments (Figs
Neotriadomerus spp. 32 N. gloriosus female head, anterior 33 N. darlingi male head + pronotum, dorsal 34 N. gloriosus lower face + mouthparts, anterior 35 N. gloriosus maxillae + labium, anterior 36 N. longissimus head, scape and mandibles, dorsoanterolateral 37 N. longissimus radicle, anterolateral (and showing 3-way junction of transverse, supraorbital and preorbital trabeculae). Scale bar for 32, 33, 36 = 100 μm; 34 = 50 μm; 35, 37 = 20 μm.
Neotriadomerus spp. 38 N. longissimus female scape–base of fl2, lateral 39 N. sp. female fl8 + clava, lateral 40 N. darlingi male apex of pedicel–base of fl2, lateral 41 N. darlingi male fl11–fl13, lateral 42 N. darlingi male fl11, lateral 43 N. darlingi male apex of fl11, lateral. Scale bar for 38 = 100 μm; 39, 41 = 50 μm; 40, 42, 43 = 20 μm.
Neotriadomerus spp. 44 N. darlingi mesosoma, dorsal 45 N. sp. mesosoma, dorsolateral (arrows indicate pores) 46 N. sp. base of left wings (ventral) and surrounding mesosoma, dorsolateral 47 N. darlingi fore wing base, dorsal 48 N. longissimus fore wing base, ventral 49 N. sp., hind wing attachment to fore wing, ventral. Scale bar for 44, 45, 48 = 100 μm; 46, 47, 49 = 50 μm.
Neotriadomerus spp. 50 N. darlingi male parastigma, dorsal 51 N. longissimus female parastigma, ventral 52 N. darlingi male stigmal vein, dorsal 53 N. longissimus female calcar, lateral 54 N. sp. female calcar, dorsolateral 55 N. sp. female pretarsus, dorsolateral. Scale bar for 50, 53, 54 = 50 μm; 51 = 100 μm; 52, 55 = 20 μm.
Neotriadomerus spp. 61 N. sp. apex of gaster, lateral 62 N. sp. gt7 + ovipositor apex, lateral 63 N. longissimus ovipositor sac, lateral 64 N. sp. male ovipositor apex, lateral 65 N. darlingi apex of gaster, posterolateral 66 N. powerae male genitalia, lateral. Scale bar for 61 = 100 μm; 62 = 50 μm; 63 = 200 μm; 64–66 = 20 μm.
The name is masculine. The prefix Neo is Greek for new or recent, young, + Triadomerus, apparently the closest related genus.
Neotriadomerus species occur only in Australia where seven are described (below) and as many as four others are illustrated (Figs
Hosts are unknown. The estimated ovipositor length, when fully extended, is about 12 mm for the largest species of Neotriadomerus. This suggests that its host might be eggs of Orthoptera laid quite deeply inside plant tissue or in soil. Perhaps only Orthoptera, but possibly Coleoptera or Cicadidae, would have eggs long enough to host a developing female parasitoid (5.9 mm long) of this species. Specimens of Neotriadomerus have been collected in a variety of habitats in all Australian states except Victoria and Tasmania. Some specimens have been collected at light, suggesting they may be active at night.
Females.
1 | Body 5000 long; ovipositor at least 5900 long, extending anteriorly under mesosoma to well beyond level of head (Fig. |
N. longissimus sp. n. |
– | Body at most about 2600 long; ovipositor at most 2240 long, extending under mesosoma at most to level of head (Figs |
2 |
2(1) | Fore wing with cubital line of setae extending proximally to base of parastigma, i.e., clearly proximal to other microtrichia on wing surface (Figs |
3 |
– | Fore wing with cubital line of setae extending proximally only to apex of parastigma, about level with other microtrichia on wing surface (Figs |
9 |
3(2) | Fl1 with 2 mps; fl2 with about 4 (5?) mps (Fig. |
N. burwelli sp. n. |
– | Fl1 with at least 4 mps; fl2 with at least 6 mps (Figs |
4 |
(3) | Fl2 with 2 barely overlapping whorls of mps (Figs |
5 |
– | Fl2 with 1 whorl of mps (Fig. |
6 |
5(4) | Fl8 length/width 2.6 (Fig. |
N. sp. 1 |
– | Fl8 length/width 2.2 (Fig. |
N. sp. 3 |
6(4) | Fl1 about 0.7× as long as fl2 (Fig. |
N. gloriosus sp. n. |
– | Fl1 at least 0.9× as long as fl2 (Figs |
7 |
7(6) | Fl2–fl7 each slightly more than 2.0 × as long as wide; clava about 3.2× as long as wide | N. powerae sp. n. |
– | Fl2–fl7 each at most 1.6× as long as wide; clava about 2.6× as long as wide (Fig. |
8 |
8(7) | Fl2–fl3 each about 1.6× as long as wide | N. crassus sp. n. |
– | Fl2–fl3 each almost quadrate | N. sp. 2 |
9(2) | Ovipositor extending anteriorly under mesosoma to level of head (Figs |
N. longiovipositor sp. n. |
– | Ovipositor extending anteriorly under mesosoma to level of apex of procoxa (Fig. |
N. darlingi sp. n. |
Males.
Males of darlingi, longiovipositor and powerae are known and almost certainly correctly associated with the corresponding females; males are unknown for N. burwelli, N. crassus, N. gloriosus and N. longissimus. Two unnamed males are also keyed; one (sp. 4) is not definitely associated with a female and the other (sp. 1) is definitely associated with a female.
1 | Fore wing with cubital line of setae extending at least to base of parastigma, clearly proximal to other microtrichia on wing surface (Fig. |
2 |
– | Fore wing with cubital line of setae extending at most to apex of parastigma (level with distal macrochaeta), about level with other microtrichia on wing surface (Fig. |
4 |
2(1) | Fl6 wider, its length/width about 1.8 (Fig. |
Neotriadomerus sp. 4 |
– | Fl6 narrower, its length/width at least 2.0 (Fig. |
3 |
3(2) | Fl6 about 2.0 | N. powerae sp. n. |
– | Fl6 about 3.5 | N. sp. 1 |
4(1) | Flagellomeres each with 2 barely overlapping whorls of shorter mps (Fig. |
N. longiovipositor sp. n. |
– | Flagellomeres each with 1 whorl of longer mps (Fig. |
N. ? darlingi sp. n. |
Holotype female (
Neotriadomerus burwelli differs from the other small (body length less than 2600) species of Neotriadomerus, as follows: fore wing with cubital line extending proximally to base of parastigma (Fig.
Female. Body length ≈ 1590 (holotype). Colour. Holotype body almost uniformly dark brown; legs brown, with trochantelli, base and apex of femora and entire protibia, base and apex of meso- and metatibiae, and tarsi except tarsomere 5 paler, almost white; tarsomere 5 brown. Head. Head width 305 (Figs
Male. Unknown.
The species is named after Chris Burwell, curator of insects at the Queensland Museum, who collected the only known specimen of this species.
Holotype female (
Neotriadomerus crassus differs from the other small (body length less than 2600) species of Neotriadomerus as follows: fore wing with cubital line extending proximally to about base of parastigma (Fig.
Female. Body length ≈ 1685 (holotype). Colour. Body almost uniformly dark brown; legs brown, with trochantelli, base and apex of femora and entire protibia, base and apex of meso- and metatibiae, and tarsi except tarsomere 5 of all legs and metatarsomere 1 paler, almost white; tarsomere 5 brown and metatarsomere 1 light brown. Head. Width not measurable (Fig.
Male. Unknown.
The species name, crassus, is Latin for thick or stout, referring to the fairly short, thick funicle segments in females.
Holotype female (
Paratypes. 3 females, 1 male. AUSTRALIA. South Australia: Same locality data as holotype (1 ♀ and 1♂,
Two males with the following data questionably belong to this species so are not labelled as paratypes. They were collected from South Australia, Brookfield Conservation Park, 34.21°S, 139.29°E, 17 & 18.ii.1992, J. Cardale, A. Roach, light trap (2♂,
Neotriadomerus darlingi differs from the other small (body length less than 2600) species of Neotriadomerus as follows: fore wing with cubital line extending proximally to about level of other microtrichia (Fig.
Female. Body length 1420–1560 (n=2, card-mounted paratypes). Colour. Body (Fig.
Male. Body length 1330 (point-mounted paratype) and 1230 (slide-mounted specimen, Brookfield Conservation Area). Colour as for female but with legs almost entirely brown (Fig.
The species is named after Chris Darling, curator of Entomology at the Royal Ontario Museum, Toronto, who collected the type series.
Holotype female (
Neotriadomerus gloriosus differs from the other small (body length less than 2600) species of Neotriadomerus, as follows: fore wing with cubital line extending to just proximal to base of parastigma (Fig.
Female. Body length ≈ 1840 (holotype). Colour. Holotype body almost uniformly dark brown; legs brown, with trochantelli, base and apex of femora and entire protibia, and base and apex of meso- and metatibiae, and tarsi except tarsomere 5 paler, almost white; tarsomere 5 brown. Head. Head width 374 (Figs
Male. Unknown.
The species is named after the type locality, Mt. Glorious National Park.
Holotype female (
Paratypes. 4 females, 4 males, 1 deformed male (gynandromorph?). AUSTRALIA. Queensland: Batavia Downs, 12.40°S; 142.39°E, 22.vi–23.viii.1992, P. Zborowski & J. Cardale, flight interception trap (1♂,
Neotriadomerus longiovipositor differs from the other small (body length less than 2600) species of Neotriadomerus, as follows: fore wing with cubital line extending proximally to about level of other microtrichia (Fig.
Female. Body length ≈ 1700–2250 (n=6). Colour. Body (before slide mounting one specimen) uniformly shiny black except mouthparts brown; antenna dark brown but scape and pedicel ventrally slightly lighter; pro- and mesocoxa dark brown except extreme apices yellowish, metacoxa dorsally almost black; the rest of each leg yellowish except for femur ventrally of fore- and mid leg, entire femur except extremities of hind leg, and apical tarsomere of all legs brown. Head. Head width 344–412 (Figs
Male. Colour. As for female. Head. Head (Figs
The name is a noun in apposition, referring to the long ovipositor (the second longest in the genus) that extends anteriorly to the head.
Holotype female (
Paratype. 1 female. AUSTRALIA. Queensland: Brisbane Forest Park, 27°25'04"S; 152°49'48"E, 23–29.x.1998, N. Power, dry sclerophyll, MT (1♀,
Neotriadomerus longissimus differs from other species of Neotriadomerus as follows: body 5000—almost twice the length of any other species (Fig.
Female. Body length 5000–5450 (n=2, card and point-mounted holotype and paratype), excluding basal sac of gaster (5900–6300 if this included). Colour. Holotype body black except for brown mandibles, scutellum, and most of middle segments of metasoma; legs and apex of anterior extension of ovipositor brownish yellow; paratype body (Figs
Male. Unknown.
The species name, longissimus, is Latin for longest, referring the extremely long gaster.
Holotype female (
Paratypes. 1 female, 3 males. AUSTRALIA. Queensland: Same data as holotype but 14–20.iii.1998 (1♀ and 1♂,
Neotriadomerus powerae differs from other small (body length less than 2600) species of Neotriadomerus as follows: fore wing with cubital line extending to just proximal to base of parastigma (Fig.
Female. Body length ≈ 1560 (holotype). Colour. Body (Fig.
Male. Colour. As for female (Fig.
The species is named after Narelle Power, who ran a Malaise trap for many months in Brisbane Forest Park.
AUSTRALIA. Australian Capital Territory: 3 km E. Piccadilly Circus, Blundells Creek, 35.22°S, 148.50°E, 850m, xii.1984, Weir, Lawrence, Johnson (1♀ and 1♂,
The female (Fig.
AUSTRALIA. Western Australia: 29 km SE by E of Coolgardie, 31.07°S, 121.24°E, 5.v.1983, E.S. Nielsen, E.D. Edwards (1♀,
Body length 1380. Female antenna with 1whorl of mps on each segment and the shortest and widest funicle segments (Fig.
AUSTRALIA. New South Wales: Kosciusko National Park, Leather Barrel Creek, 0.8 km SW. Picnic Area, 36°32'S, 148°11'E, 1080m, 7–21.ii.1993, A. Newton, M. Thayer, open Eucalyptus forest (gum + delegatensis) with shrubby understory, window trap (1♀,
Body length 1920; fore wing with cubital line of setae extending to base of parastigma. This specimen is similar to the female from Blundells Creek but fl1 is even shorter than fl2 so it is provisionally treated as distinct.
AUSTRALIA. Northern Territory: 12 km WNW Ross River, Tourist Camp, 23.32°S, 134.23°E, 13.v.1978, J.C. Cardale (1♂,
Male. Body length ≈ 1330. Colour. Body almost uniformly dark brown; legs brown, with trochantelli, base and apex of femora and tibiae, and tarsi except tarsomere 5 paler; tarsomere 5 brown. Antenna. Measurements, length/width: scape 139/46, pedicel length/width 52/46, flagellar segment length: fl1 100/68, fl2 94/67, fl3 97/61, fl4 100/56, fl5 100/56, fl6 98/54, fl7 96/54, fl8 96/53, fl9 92/50, fl10 87/46, fl11 94/37; total flagellar length 1053; fl6 length/width 1.81, with 11 (12?) mps (Fig.
The flagellar segments are wider than those of N. darlingi (Figs
Borneomymar primitivum Huber, by present designation.
Female. Antenna with funicle 8-segmented (in Arescon 5-segmented) and clava 1-segmented, gradually narrowing apically to a point (Figs
Female. Body 635–720 in length (critical point dried). Colour. Body generally light brown with some areas yellow to creamy white; darker brown are mouth margin, trabeculae, ocellar triangle, clava except apex, dorsellum, meso- and metapleuron, propodeum, and gt4–gt5 (Figs
Male. Body length ≈ 585 (slide mounted paratype). Colour. Similar to female but with slightly more extensive brown on mesosoma (Fig.
The genus is masculine. The prefix, pro- is Latin for in front of, earlier or first, + Arescon, apparently the most closely related genus.
Females.
1 | Clava 4.7× times as long as wide, with ventral margin distinctly concave (Figs |
P. similis Huber, sp. n. |
– | Clava less than 3.5× as long as wide, with ventral margin almost straight ( |
P. primitivus (Huber) |
Borneomymar primitivum Huber, 2002: 49 (description, figs 5, 6).
In
Female. Body length 634 (paratype). Antenna. Length/width measurements (holotype): scape 184/35, pedicel 50/26, fl1 16/13, fl2 16/12, fl3 23/16, fl4 26/16, fl5 29/18, fl6 62/25, fl7 59/26, fl8 63/31, clava 120/35.Wings. Fore wing length 583, width 154, length/width 3.78, longest marginal setae 122. Hind wing length 560, width 23, longest marginal setae 90.
THAILAND: Chanthaburi, Khao Kitchakut Nat. Park, Khao Prabaht Peak, 12°50.45'N 102°9.81'E, 875m, 27.ii-6.ii.2009, MT, Suthida and Charoenchai, #4046 (1♀,
Holotype female (
Paratypes. 1 female and male. THAILAND. Nakhon Si Thammarat. Namtok Yong Nat. Park, TV aerial, 966m 8°14.262'N; 99°48.289'E, 15-22.ix.2008, Malaise trap, Paiboon, #3540 (1♂ on slide,
Female. Clava 4.7× times as long as wide, with ventral margin distinctly concave (in P. primitivus, clava about 3.4× as long as wide, with ventral margin almost straight); fore wing with cubital line not extending proximally beyond first apical macrochaeta, barely proximal to remainder of microtrichia (in P. primitivus, cubital line extending proximally almost to level of proximal macrochaeta, distinctly proximal to other microtrichia).
Female. Body length 740 (holotype), 634 (paratype on card). Head. Head width 182 (holotype). Face with weak elongate reticulate sculpture, vertical laterally becoming horizontal medially, with thin setae distributed on each side as follows: 2 medial to torulus and 7 ventral to torulus, the 2 setae submedially above mouth margin longer and thicker than the others (Fig.
Male. Colour. As in generic description. Head. Head width 192 (n=1). Wings. Fore wing length (n=1) 563, width 146, length/width, 3.88, longest marginal setae 107. Hind wing length 542, width 26, longest marginal setae 114. Antenna. Measurements (n=1): scape length/width 74/22, pedicel length/width 30/37, flagellar segment length: fl1 44, fl2 59, fl3 62, fl4 61, fl5 60, fl6 60, fl7 64, fl8 61, fl9 61, fl10 62, fl11 58; total flagellar length 652; fl6 length/width 2.73, with 4 mps (Fig.
The species name, similis, is Latin for similar, referring to the similarity of this species to the only other described species in Proarescon.
Proarescon similis, male. 159 mesosoma, dorsal 160 base of wings + axilla, dorsal 161 fore wing, dorsal 162 mesosoma, laterodorsal 163 apex of gaster + genitalia, dorsolateral 164 apex of gaster + genitalia, ventral. Scale bar for 159 = 50 μm; 160, 163, 164 = 20 μm; 161 = 200 μm; 162 = 100 μm.
Borneomymar discus
Female. Head without stemmaticum (Fig.
Borneomymar
madagascar
: Huber, 2002: 48 (original description);
This species differs from, B. discus Huber, the only other extant species now included in the genus, as follows: radicle about as long as wide, scape 2.84× as long as wide (in B. discus radicle much longer than wide, scape 5.86× as long as wide); fore wing uniformly hyaline (Fig.
Female. Body length 922–998 (n = 4, critical point dried specimens, measured to apex of hypopygium), ovipositor length ≈ 2022–2330 (not completely straight so probably slightly longer). Head (Fig.
MADAGASCAR. Antananarivo. Botanic garden near entrance to Andasibe National Park, 1025 m, 18°55.58'S; 48°24.47'E, 1-5.xi.2001, R. Harin’Hala, tropical forest, Malaise trap, lot # 007164 (1♀ on slide,
I treat Yoshimoto's Triadomerinae as a tribe, defined as follows, based mainly on extant genera and species: mandible with 3 (Borneomymar, Eustochomorpha) or 4 teeth; pronotum entire; fore wing wide, with marginal setae much shorter than wing width; venation more than 85% of wing length, with marginal vein present and longer than submarginal vein, and with postmarginal vein present and longer than marginal vein; hypochaeta, when present, closer to proximal than to distal macrochata; hind wing wide with marginal setae shorter than wing width; tarsi 5-segmented, with tarsomere 1 distinctly longer than any of the others; petiole clearly shorter than wide, ring like. Female. Antenna with flagellum at most 11 segmented (funicle 8-segmented and clava 1–3-segmented); ovipositor usually greatly exserted beyond either posterior (Borneomymar, Eustochomorpha) or anterior (Neotriadomerus) apex of body but in the extinct genera not projecting either anteriorly or posteriorly. Male. Antenna 11-segmented, the flagellomeres each with several mps; genitalia encapsulated, with short, thick parameres, apparently without digiti (in Neotriadomerus) but thinner walled and with digiti (in Borneomymar)
Triadomerini is treated here as the sister clade to the remainder of Mymaridae. The only apomorphy that defines the tribe is reduction in number of flagellar segments (at most 11) relative to Rotoitidae, whose species have a 12-segmented flagellum in females of both included extant genera. An additional diagnostic feature of the extant species of Triadomerini is the exserted cerci on a distinct prominence, similar to that of Torymidae. The occurrence of elevated cerci, number of teeth in mandibles, and several other features cannot definitely be determined from the fossil specimens studied. The lack of a hypochaeta apparently occurs in Triadomerus and Eustochomorpha and apparently also in at least one of the Neotriadomerus species.
Triadomerus is known only from Cretaceous amber from present day western Canada (
Arescon is almost worldwide (
See
1 | Clava 2 or 3-segmented; propodeum with 2 or 3 setae | 2 |
– | Clava 1-segmented (i.e., entire); propodeum with 1 seta | 5 |
2(1) | Clava 2-segmented | 3 |
– | Clava 3-segmented [ovipositor extending anteriorly well under mesosoma but not exserted posteriorly much beyond gastral apex (Figs |
Neotriadomerus Huber, gen. n. |
3(2) | Ovipositor extending posteriorly well beyond posterior apex of gaster (Figs |
Eustochomorpha haeckeli Girault |
– | Ovipositor not or barely exserted beyond posterior apex of gaster; tarsi 3- or 4-segmented; funicle 4- or 5-segmented | 4 |
4(3) | Tarsi 4-segmented; funicle 5-segmented | Tinkerbella Huber & Noyes |
– | Tarsi 3-segmented; funicle 4-segmented | Kikiki Huber & Beardsley |
5(1) | Funicle 5-segmented | Arescon Walker |
– | Funicle 8-segmented | 6 |
6(5) | Fl1–fl5 each much shorter than fl6–fl8 (Fig. |
Proarescon Huber, gen. n. |
– | Fl1–fl5 as long as fl6–fl8 ( |
Borneomymar Huber |
The distribution of the extinct and extant genera that can definitely be placed in Mymaridae encompasses a time span of almost 100 my.
The widespread distribution of Mymaridae already existed at least 80 my ago (described taxa from Canadian and Burmese Cretaceous amber) and the family is currently worldwide, except for Antarctica. Two scenarios may explain this: 1) The family may have evolved before the breakup of Pangaea, 200–180 million years ago, and was already widespread throughout the supercontinent wherever suitable hosts occurred, which would suggest a Jurassic origin; 2) The family is more recent, having originated in only part of Pangea, probably Gondwana, and some species then spread to Laurasia after the two parts became well separated from each other. This is quite possible because Mymaridae are small and easily carried long distances on wind and some would have survived the trip. Mymaridae as a recognizable taxon may therefore be a lot older than the present evidence shows, going back well into the early Cretaceous.
The following curators and collectors are thanked for sending specimens for study: J. Cardale (