Gryon Haliday, 1833

Talamas, Elijah J., Bremer, Jonathan S., Moore, Matthew R., Bon, Marie-Claude, Lahey, Zachary, Roberts, Cheryl G., Combee, Lynn A., McGathey, Natalie, van Noort, Simon, Timokhov, Alexander V., Hougardy, Evelyne & Hogg, Brian, 2021, A maximalist approach to the systematics of a biological control agent: Gryon aetherium Talamas, sp. nov. (Hymenoptera, Scelionidae), Journal of Hymenoptera Research 87, pp. 323-480 : 323

Gryon Haliday

Gryon Haliday, 1833: 271 (original description. Type species: Gryon misellum Haliday, by monotypy, keyed); Walker, 1836: 343 (description); Westwood, 1840: 77 (description); Blanchard, 1840: 289 (junior synonym of Teleas Latreille); Brullé, 1846: 619 (description); Förster, 1856: 101, 105 (diagnosis, keyed); Marshall, 1873: 16 (catalog of species of Britain); Walker, 1874: 9 (keyed); Howard, 1886: 172 (keyed); Cresson, 1887: 84 (keyed); Ashmead, 1893: 181, 205 (description, keyed, key to species of U.S. and Canada); Dalla Torre, 1898: 502 (catalog of species); Ashmead, 1900: 327 (list of species of West Indies); Ashmead, 1903: 90 (keyed); Kieffer, 1908: 188, 189 (description, keyed); Brues, 1908: 19, 25, 49 (diagnosis, keyed, list of species); Kieffer, 1910: 91, 92 (description, list of species, keyed); Kieffer, 1912: 109 (description); Kieffer, 1913: 212 (description, taxonomic status, key to species of Europe and Algeria); Dodd, 1914a: 75 (keyed); Kieffer, 1926: 173, 260 (description, keyed, key to species); Morley, 1929: 54 (catalog of species of Britain); Dodd, 1930: 42 (keyed); Nixon, 1936: 115 (taxonomic status, position); Maneval, 1940: 112, 113 (keyed); Fouts, 1948: 92 (keyed); Muesebeck & Walkley, 1951: 356 (citation of type species); Masner, 1961: 158 (synonymy, systematic position, description); Kozlov, 1963a: 354, 357 (description, key to species of USSR, keyed); Kozlov, 1963b: 661, 667 (description, keyed, key to species); Szabó, 1966: 422 (keyed); De Santis, 1967: 225 (catalog of species of Argentina); Safavi, 1968: 418 (parasitized eggs of Scutelleridae keyed); Hellén, 1971: 5, 21 (description, keyed); Kozlov, 1971: 38 (keyed); Kozlov, 1972: 654 (key to new species described); Alayo Dalmau, 1973: 99 (catalog of species of Cuba); Simons, Reardon & Ticehurst, 1974: 15 (keyed); Viggiani & Mineo, 1974: 160, 161 (keyed); Mani & Mukerjee, 1976: 497 (key to new species described); Masner, 1976: 7, 57 (description, synonymy, keyed); Fergusson, 1978: 118 (checklist of species of Britain); Kozlov, 1978: 619 (description, key to species of European USSR); Mineo, 1979b: 91 (diagnosis, key to species parasitizing Aelia and Eurygaster ( Hemiptera : Pentatomidae )); Muesebeck, 1979: 1157 (catalog of species of U.S. and Canada); Masner, 1980: 12, 13 (keyed); Mineo, 1980b: 216 (diagnoses and keys to species of Gryon insulare and Gryon pubescens species groups); De Santis, 1980: 311 (catalog of species of Brazil); Mineo, 1981a: 119 (description and key to species of the Gryon muscaeformis species group); Mani & Sharma, 1982: 152, 191 (description, keyed); Mineo & Villa, 1982b: 175 (taxonomic value of pleural structures, clypeus, and antennal sensilla); Mineo & Villa, 1982a: 134 (taxonomic value of structures on the posterior surface of the head); Sharma, 1982: 336 (key to species of India); Masner, 1983: 126, 127 (description, morphology, division into species groups, key to species of North America, keyed); Mineo, 1983b: 285 (description and key to species of the Gryon pubescens species group); Mineo, 1983c: 546, 551 (descriptions and keys to species of the Gryon insulare and Gryon oculatum species groups); Mineo, 1983a: 12 (description and key to species of the Gryon charon species group); Galloway & Austin, 1984: 6, 78 (diagnosis, synonymy, list of species described from Australia, keyed); Mineo & Caleca, 1987b: 41 (diagnoses of the Gryon misellum , Gryon artum , Gryon austrafricanum and Gryon hospes species groups; key to species of the Gryon artum group); Kozlov & Kononova, 1989: 78 (key to species of the USSR); Kozlov & Kononova, 1990: 96, 265, 266 (description, division into species groups, key to species of Palearctic, keyed); Caleca, 1990a: 116 (description, key to species of Gryon pentatomum group); Mineo, 1990a: 171, 174, 180, 182 (description of Gryon artum , Gryon muscaeforme , Gryon myrmecophilum , Gryon oculatum , Gryon pubescens groups); Mineo, 1990b: 49, 52 (description of Gryon hiberus , Gryon leptocorisae species groups); Mineo, 1990c: 90 (description of Gryon letus group, key to species of Gryon letus group); Mineo, 1991: 1, 2, 7, 9, 10, 12 (description of Gryon aculum , Gryon acuteangulatum , Gryon aureum , Gryon cydnoide , Gryon hungaricum , Gryon introversum species groups, synonymy, key to species of Gryon hungaricum group); Johnson, 1992: 374 (cataloged, catalog of world species); Mineo & Caleca, 1994: 114, 116, 121, 127 (designation of hirsuticolum group, Gryon fulviventre subgroup of Gryon muscaeforme group, Gryon subfasciatum group, Gryon lymantriae group, key to species of Gryon lymantriae group); Kononova, 1995: 62, 81 (keyed, diagnosis, key to species of Russian Far East); Austin & Field, 1997: 36, 68 (structure of ovipositor system, discussion of phylogenetic relationships); Lê, 2000: 32, 95 (keyed, description, key to species of Vietnam); Kononova & Petrov, 2001: 1468 (description); Kononova & Petrov, 2002: 53 (key to species of Palearctic); Loiácono & Margaría, 2002: 557 (catalog of Brazilian species); Rajmohana K., 2006: 115, 123 (description, keyed); Fabritius & Popovici, 2007: 11, 13, 14, 26, 29, 63 (description, key to Romanian species, key to species related to Gryon longiabdominalis and buhli, keyed); Kononova & Kozlov, 2008: 25, 321, 322 (description, keyed, key to species of Palearctic region); Popovici & Johnson, 2012: 382 (description of internal genitalia); Rajmohana, 2014: 8, 33 (description, keyed); Talamas & Buffington, 2015: 21 (fossil in Dominican amber). Comments. The lectotype and paralectotype specimens of G. misellum Haliday are in excellent condition considering their age (~190 years old) and these specimens display all the diagnostic characters that we associate with the genus (Figures 21 - 25 ).

Acolus Förster, 1856: 100, 102 (original description. Type species: Acolus opacus Thomson, designated by Ashmead (1903), keyed. Synonymized by Masner (1961)); Thomson, 1859: 417, 422 (description, keyed); Walker, 1874: 9 (keyed); Howard, 1886: 172 (keyed); Cresson, 1887: 83, 313 (keyed, catalog of species of U.S. and Canada); Ashmead, 1893: 167, 168, 174 (description, keyed); Dalla Torre, 1898: 510 (catalog of species); Ashmead, 1903: 88, 89 (keyed); Kieffer, 1908: 179, 180 (description, key to species, keyed); Brues, 1908: 14, 15, 16, 47 (diagnosis, keyed, list of species); Kieffer, 1910: 100, 101 (description, list of species, keyed); Kieffer, 1912: 89, 92 (description, key to species of Europe and Algeria); Kieffer, 1912: 55 (key to species of Seychelles); Dodd, 1914a: 58, 70 (key to species of Australia, keyed); Brues, 1916: 542 (keyed); Kieffer, 1926: 133, 156 (description, keyed, key to species); Jansson, 1939: 173 (keyed); Maneval, 1940: 111 (keyed); Muesebeck & Walkley, 1956: 324 (citation of type species); Masner, 1961: 158 (junior synonym of Gryon Haliday).

Plastogryon Kieffer, 1908: 119, 141 (original description. Type: Plastogryon foersteri Kieffer, designated by Brues (1908)); Brues, 1908: 51 (diagnosis, list of species, type designation); Kieffer, 1910: 65, 81 (description, list of species, keyed); Dodd, 1913a: 131 (keyed); Kieffer, 1913: 230, 245 (description, key to species of Europe and Algeria); Dodd, 1915: 24 (key to species of Australia); Dodd, 1915: 24 (key to species of Australia); Kieffer, 1926: 270, 446 (description, keyed, key to subgenera, key to species); Jansson, 1939: 172 (keyed); Muesebeck & Walkley, 1956: 385 (citation of type species); Masner 1961: 158 (junior synonym of Gryon Haliday).

Psilacolus Kieffer, 1908: 179, 180 (original description. Type species: Acolus xanthogaster Ashmead, designated by Kieffer (1926)); Brues, 1908: 47 (diagnosis, list of species); Kieffer, 1910: 100, 101 (description, list of species, keyed); Kieffer, 1912: 88 (description); Dodd, 1914a: 59 (keyed); Kieffer, 1926: 132, 151 (description, keyed, key to species); Muesebeck & Walkley, 1956: 393 (citation of type species); Muesebeck & Masner, 1967: 299 (junior synonym of Gryon Haliday).

Holacolus Kieffer, 1912: 89, 106 (original description. Type species: Acolus opacus Thomson, designated by Muesebeck & Walkley (1956). Key to species of Europe and Algeria); Kieffer, 1926: 133, 169 (description, keyed, key to species); Jansson, 1939: 173 (keyed); Maneval, 1940: 111 (keyed); Muesebeck & Walkley, 1956: 359 (designation of type species); Masner, 1961: 158 (junior synonym of Gryon Haliday).

Plesiobaeus Kieffer syn. rev., 1913: 229, 282 (original description. Type: Plesiobaeus hospes Kieffer, by monotypy); Kieffer, 1926: 271, 556 (description, keyed); Morley, 1929: 54 (catalog of species of Britain); Jansson, 1939: 172 (keyed); Maneval, 1940: 112 (keyed); Muesebeck & Walkley, 1956: 386 (citation of type species); Szabó, 1966: 422 (keyed); Kozlov, 1971: 38 (keyed); Fergusson, 1978: 118 (checklist of species of Britain); Kozlov, 1978: 621 (description); Mineo, 1979a: 248 (junior synonym of Gryon Haliday); Masner, 1980: 13 (keyed); Kozlov & Kononova, 1990: 96, 265, 307 (description, keyed); Fabritius & Popovici, 2007: 11, 34, 63 (description, keyed); Kononova & Kozlov, 2008: 25, 445 (description, keyed, treated as valid genus). Comments. Mineo (1979a) stated that Plesiobaeus hospes seemed to be conspecific with Gryon misellum based on its original description. He also stated that the type was examined but did not provide characters based on this examination to support the generic transfer. Mineo and Caleca (1987b) reported that the species in this group, containing only G. hospes , had a 1-2-2-0 claval formula, which is consistent with some species of Gryon , e.g., G. moczari , whereas no species of Hadronotus known to us has such a claval formula.

Hadronotellus Kieffer, 1917: 341 (original description. Type: Hadronotellus pedester Kieffer, by monotypy and original designation. Synonymized by Kieffer (1926)); Muesebeck & Walkley, 1956: 357 (citation of type species); Szabó, 1966: 421, 422 (description, key to Palearctic species known to the author, keyed); Hellén, 1971: 5, 22 (description, keyed).

Heterogryon Kieffer, 1926: 271, 446, 448 (original description. Type: Plastogryon sagax Kieffer, designated by Muesebeck & Walkley (1956). Proposed as a subgenus of Plastogryon , keyed. Synonymized by Masner (1961)); Muesebeck & Walkley, 1956: 359 (designation of type species); Masner, 1961: 158 (junior synonym of Gryon Haliday).

Eremioscelio Priesner syn. rev., 1951: 129 (original description. Type: Eremioscelio cydnoides Priesner, by monotypy and original designation); Muesebeck & Walkley, 1956: 351 (citation of type species); Kozlov, 1963a: 354, 357 (description, keyed); Kozlov, 1963b: 661, 666 (description, keyed); Kozlov, 1971: 38, 49 (synonymy, keyed); Kozlov, 1972: 656 (key to species); Masner, 1976: 59 (description); Kozlov, 1978: 621 (description, key to species of European USSR); Kozlov & Kononova, 1990: 95, 265, 310, 311 (description, key to species of USSR, keyed); Mineo, 1991: 1, 9 (junior synonym of Gryon Haliday, described as Gryon cydnoide species group); Johnson, 1992: 372 (cataloged, catalog of world species); Kononova, 1995: 62, 85 (keyed, diagnosis, key to species of Russian Far East); Fabritius & Popovici, 2007: 11, 36, 63 (description, key to Romanian species, keyed); Kononova & Kozlov, 2008: 25, 451 (description, keyed, key to species of Palearctic region, treated as a valid genus). Comments. Images of the holotype specimen of Eremioscelio cydnoides illustrate important diagnostic characters of Gryon : the lateral pit on T1 and the presence of subgenual spines (Figures 31 , 33 ). Examination of additional material revealed that the clypeus is anteriorly projecting with sharp corners (Figure 30 ) and that the axillula is striate (Figures 32 , 34 ). The transverse, wavy sculpture on the mesoscutum and mesoscutellum of this species is an oddity for the genus (Figures 31-32 ).

Hungarogryon Szabó syn. n., 1966: 422, 443 (original description. Type: Hungarogryon moczari Szabó, by monotypy and original designation, keyed); Kozlov, 1971: 38 (keyed); Kozlov, 1978: 621 (description); Masner, 1980: 13 (keyed); Kozlov & Kononova, 1990: 96, 265, 320 (description, keyed); Johnson, 1992: 402 (cataloged, catalog of world species); Fabritius & Popovici, 2007: 63 (keyed); Kononova & Kozlov, 2008: 25, 461 (description, keyed). Comments. Gryon moczari (= Hungarogryon moczari ) was the sole species in Hungarogryon , and is very small, only slightly longer than 0.5 mm in length. We place this species in Gryon based on the presence of subgenual spines on the hind tibia (Figure 38 ), a frons without transverse sculpture in the frontal depression (Figure 35 ), a protruding clypeus with sharp corners (Figure 35 ), and the lateral pit on T1 (Figure 37 ). However, in two characters, Gryon moczari differs from the rest of Gryon : the axillula is mostly smooth with crenulae present only along the anterodorsal margin (Figure 36 ) and the antenna has three clavomeres instead of the usual four (Figure 39 ). We consider it most likely that these characters are derived within the genus and are related to reduction in body size. The forewing has a fringe of long, delicate setae. The slide-mounted wing illustrated in Figure 40 retains only one of these setae.

Masneria Szabó, 1966: 422, 442 (original description. Type: Hadronotus lymantriae Masner, by monotypy and original designation, keyed. Synonymized by Masner (1976)); Masner, 1976: 57 (junior synonym of Gryon Haliday).

Pannongryon Szabó, 1966: 422, 435 (original description. Type: Pannongryon szelenyii Szabó, by original designation. Key to species known to author, keyed. Synonymized implicitly by Kozlov (1971), explicitly by Masner (1976)); Kozlov, 1971: 47 (junior synonym of Gryon Haliday).

Sundholmia Szabó, 1966: 422, 438 (original description. Type: Sundholmia nitens Szabó, by monotypy and original designation, keyed. Synonymized by Mineo (1980a)); Kozlov, 1971: 38 (keyed); Mineo, 1980a: 200 (junior synonym of Gryon Haliday).

Breviscelio Sundholm syn. n., 1970: 383 (original description. Type: Breviscelio crenatus Sundholm, by monotypy and original designation); Mineo & Villa, 1982b: 175 (taxonomic value of pleural structures, clypeus, and antennal sensilla); Mineo & Villa, 1982a: 138 (taxonomic value of structures on the posterior surface of the head); Caleca, 1990b: 139 (description); Johnson, 1992: 354 (cataloged, catalog of world species); Caleca, 1992: 52, 53 (key to species, discussion of relationships); Austin & Field, 1997: 39, 68 (structure of ovipositor system, discussion of phylogenetic relationships) Comments. Our treatment of Breviscelio as a junior synonym of Gryon is supported by molecular and morphological evidence. Specimens of Gryon crenatum (= Breviscelio crenatus , the type species of Breviscelio ) were retrieved within the Gryon clade in the 4-gene and COI analyses. The striate axillula and the lateral pit on T1 are visible in the holotype specimen (Figure 41 ). Figures 42-46 illustrate other specimens of Gryon crenatum from South Africa, showing that this species also has the suite of characters used to diagnose Gryon : antennal scrobe without transverse sculpture (Figure 42 ); head and dorsal mesosoma covered with microsculpture (Figures 42-44 ); metapleuron mostly glabrous and undivided by change in sculpture or setation (Figure 43 ), subgenual spines present on the hind tibia (Figure 46 ). The conspicuous frontal ridge in G. crenatum is associated with an elongation and oblique orientation of the mandibles. This association is known from other platygastroids, including Encyrtoscelio Dodd, Tyrannoscelio Masner, Johnson & Arias-Penna, Acanthoscelio ( Scelionidae ) and Sparasion Latreille ( Sparasionidae ) (Figures 47-50 ) and may be an adaptation for using the mandibles to dig through soil. Gryon crenatum has spines throughout the tibiae and tarsi on all legs and unusual spatulate setae found on the fore tarsus (Figure 45 ), which may also be adaptations for fossorial behavior.

Exon Masner syn. rev., 1980: 12, 22 (original description. Type: Exon californicum Masner, by original designation, keyed. Synonymized by Mineo (1980b)); Mineo, 1980b: 215 (junior synonym of Gryon Haliday); Kozlov & Kononova, 1990: 95, 265, 308 (description, key to species of USSR, keyed); Kononova & Petrov, 2002: 57 (description, key to species of Palearctic); Fabritius & Popovici, 2007: 11, 41, 63 (description, keyed); Kononova & Kozlov, 2008: 25, 446 (treated as valid genus, description, keyed, key to species of Palearctic region). Comments. Like Eremioscelio , Exon has moved in and out of Gryon since it was first described. Our examination of a paratype specimen indicates that it belongs in Gryon . The antennal scrobe lacks transverse sculpture, the metapleuron is mostly glabrous and undivided, and striation of the axillula is visible (Figures 51-52 ). Figure 53 illustrates the dorsal metasoma. The quality of the image does not enable us to see the lateral pit on T1, but the uniform size of the foveae along the anterior margin of T1 is apparent, and this supports its placement in Gryon .

Diagnosis.

Head with coriaceous microsculpture throughout; mandibles usually bidentate with teeth large and roughly equal in size, sometimes tridentate with medial tooth the smallest; clypeus projecting, typically with pointed corners; ventral frons sometimes with weakly indicated facial striae; central keel present or absent; antennal scrobe convex to concave, without transverse rugae or striation, never delimited by carinae; female antenna with ten flagellomeres (nine in G. paradigma ) and four clavomeres (three in G. moczari ); mesoscutum and mesoscutellum with coriaceous microsculpture throughout, occasionally with longitudinal striation or microsculpture in the form of transverse waves; epomial carina absent or weakly developed; netrion absent; mesoscutal suprahumeral sulcus absent; mesoscutal humeral sulcus absent or indicated by a smooth furrow; mesoscutum without humeral pit (sensu Chen et al., 2020); axillula obliquely striate; metapleuron with 1-3 setae in anterodorsal corner, sometimes with a single seta in dorsal metapleural area, otherwise glabrous; metapleuron undivided dorsoventrally by a change in sculpture or setation; hind tibia with one or two pairs of subgenual spines; foveae along anterior T1 roughly equal in size, ending in a sublateral carina followed by a lateral pit.

The two most unusual species, as far as diagnostic characters are concerned, are G. moczari and G. paradigma . The former is discussed in the comments section for the synonymy of Hungarogryon . Gryon paradigma is unusual in that the females have eleven antennomeres instead of twelve, the ventrolateral corners of the clypeus are not pointed, and the axillular striae are wavy and irregular (Figures 26-28 ). This species otherwise complies with the diagnosis above and we consider it to be a derived species of Gryon .

Figures

Figure 21. Gryon misellum, lectotype male (NMINH _ 2018 _ 11 _ 02), dorsal view.

Figures 24 - 25. Gryon misellum, paralectotype female (NMINH _ 2018 _ 11 _ 03) 24 habitus, dorsolateral view 25 mesosoma and T 1, dorsolateral view.

Figures 29 - 34. Gryon cydnoide 29 holotype female (USNMENT 01059665), head and mesosoma, anterior view 30 female (OSUC 395743) head, anterior view 31 holotype female (USNMENT 01059665), habitus, dorsal view 32 female (OSUC 395739), habitus, dorsolateral view 33 holotype female, habitus, lateral view 34 mesosoma and T 1, dorsolateral view.

Figure 35 - 40. Gryon moczari 35 female (CNC 664036), head, anterior view 36 holotype female, head and mesosoma, lateral view 37 female (CNC 664036), head and mesosoma, dorsolateral view 38 female (CNC 664036), metasoma, dorsal view 39 female (CNC 664036), antennal clava, ventrolateral view 40 female (CNC 664036), wings, dorsal view.

Figures 41 - 46. Gryon crenatum 41 holotype female (MZLU Type no. 911: 1), habitus, dorsolateral view 42 female (SAM-HYM-P 093658), head, anterior view 43 female (SAM-HYM-P 093675), head and mesosoma, lateral view 44 female (SAM-HYM-P 093658), head, lateral view 45 female (SAM-HYM-P 093658), fore tarsus, lateral view 46 female (SAM-HYM-P 093658), subgenual spines on hind tibia, posterolateral view.

Figures 47 - 50. 47 Encyrtoscelio (OSUC 334153), head, lateral view 48 Tyrannoscelio genieri Masner & Johnson (OSUC 545772), head and mesosoma, lateral view 49 Acanthoscelio (OSUC 232241), head, anterior view 50 Sparasion philippinensis (USNMENT 00872835), head, anterior view.

Figures 51 - 53. Gryon californicum, paratype female (USNMENT 01109308) 51 habitus, lateral view 52 head, anterior view 53 metasoma, dorsal view.

Figures 26 - 28. Gryon paradigma (CNC 664037) 26 head, anterior view 27 mesosoma and T 1, dorsolateral view 28 hind leg, lateral view.