Sathon falcatus (Nees, 1834)

Liu, Zhen, Liu, Jia-Jun, He, Jun-Hua & Chen, Xue-Xin, 2023, First record of the genus Sathon Mason, 1981 (Hymenoptera, Braconidae, Microgastrinae) in China, Journal of Hymenoptera Research 95, pp. 85-94 : 85

Sathon falcatus (Nees, 1834)

Microgaster falcatus Nees von Esenbeck 1834: 175; type lost, Neotype designated by Wilkinson 1945: 113, ♀ - Germany: Zoologisches Museum, Hamburg University.

Microgaster equestris Haliday, 1834. Synonymized by Curtis 1837: 116.

Apanteles equestris ; Hincks, 1944: 20.

Apanteles priapus Gautier & Cleu, 1927. Syn. by Wilkinson 1945: 133.

Apanteles gladiator Szepligeti, 1901. Syn. by Tobias 1971: 246.

Sathon falcatus : Mason 1981: 78; Williams 1988: 560.

Diagnosis.

Body length 3.3-3.5 mm, fore wing length 3.6-3.8 mm. Antenna nearly 1.1 × longer than body length, preapical segment of antenna 1.3 × longer than wide. Scutellar sulcus curved, narrow with spare carinae in between. Propodeum 1.8 × wider than long, not shiny, densely longitudinally rugose medially, with punctate-rugose aside, largely polished on anterior-medial part and posterior corners. Pterostigma 2.3 × as long as its widest part. Tergite I slightly narrowing towards posterior margin, 2.2 × longer than hind width, turned-over part as long as wide, shallowly and independently punctate, weakly rugulose-punctate laterally. Tergite II weakly striate laterally, polished medially, strongly curved apically. Ovipositor sheath 0.8 × length of hind tibia, falcate.

Head. Transverse in dorsal view, 1.9 × as wide as long, 1.1 × wider than mesoscutum. Eyes 1.6 × longer than temple dorsally. Gena slightly dull with poorly defined, shallow punctures, constricted behind eyes from dorsal view (Fig. 1e ). Face (Fig. 1f ) a little shiny with fine, sparse punctures with intervals 2-4 times of a puncture diameter, transverse, 0.8 × as high as wide, sparsely pubescent. Ocelli big, posterior tangent to anterior ocellus just touching posterior pair of ocelli, distance between fore and a hind ocelli shorter than diameter of an hind ocellus, hind ocelli separated from one another by 1.5 × their own diameter and from eye by 1.4 × their own diameter. Antenna nearly 1.1 × longer than body length, preapical segment of antenna 1.3 × longer than wide (Fig. 1g ).

Mesosoma. Length:width:height = 29.0:17.5:20. Mesoscutum (Fig. 1j ) shiny, no notaulic courses, punctures fine, intervals 2-3 × of a puncture diameter, a little sparser posteriorly. Scutellar sulcus curved, narrow with spare carinae in between. Scutellum shiny, with sparse punctures, intervals 2-4 × of a puncture diameter. Propodeum (Fig. 1i ) 1.8 × wider than long, not shiny, densely longitudinally rugose medially, with punctate-rugose aside, largely polished on anterior-medial part and posterior corners. Mesopleuron (Fig. 1l ) highly shiny, largely polished, except anterior part shallowly punctate, intervals 2-3 × of a puncture diameter.

Legs. Hind coxa shallowly punctate dorsally. Inner spurs of hind tibia half-length of hind basitarsus, outer spur 2/5. Basitarsus of hind leg as long as tarsomeres 2-4.

Wings. Pterostigma 2.3 × as long as its widest part (Fig. 1c ). Vein 1-R1 1.4 × length of pterostigma, nearly 4.0 × longer than its distance from apex of marginal cell. Vein r arising from apex of pterostigma, nearly perpendicular to and 0.8 × as long as width of latter, r 1.2 × longer than 2-SR, distinctly angled at meeting, 2-M 4/5 length of 2-SR. First discal cell of fore wing nearly 1.2 × wider than high. Second submarginal cell of hind wing 1.5 × wider than high, vein cu-a of hind wing a little incurved (Fig. 1d ).

Metasoma. 1.4 × longer than mesosoma. Tergite I (Fig. 1i ) slightly narrowing towards posterior margin, 2.2 × longer than hind width, basal width 1.4 × longer than apical width, basal 2/5 concave, turned-over part as long as wide, shallowly and independently punctate, weakly rugulose-punctate laterally, no longitudinal channel. Tergite II weakly striate laterally, polished medially, 1.9 × wider than long in middle, strongly curved apically. Tergite III 1.6 × longer than tergite II. Tergites posterior to tergite II polished, shiny, and sparsely pubescent. Hypopygium a little shorter than apex of metasoma. Ovipositor sheath 0.8 × length of hind tibia, falcate.

Colour. Black (Fig. 1a ). Tegula brown. Palpi blackish brown and spurs pale yellow. Flagellum of antenna dark brown. Mandible yellowish brown. Legs mainly reddish yellow, except sometimes hind femur, apical fourth and all tarsi fulvous. Wing membrane hyaline, vein and pterostigma brown.

Male. Similar to female, except preapical segment of antenna much longer, 2.5 × longer, colouration of legs lighter (Fig. 1b ).

Hosts.

Noctuidae : Actinotia polyodon (Clerck, 1759), Apamea lateritia (Hufnagel, 1766), Apamea monoglypha (Hufnagel, 1766); Pterophoridae : Adaina microdactyla ( Hübner, 1813); Sesiidae : Synanthedon tipuliformis Clerck, 1759; Zeiraphera griseana ( Hübner, 1799); Tortricidae : Rhyacionia buoliana (Denis & Schiffermüller, 1775) ( Yu et al. 2016; Fernandez-Triana et al. 2020, see comments above).

Material examined.

(ZJUH). 15♀♀ 5♂♂, Luanchaigou , Helan Mountain, Inner Mongolia, 26.VII.2010, Jie Zeng, Nos. 201006962, 201007079, 201006956, 201006892, 201006933, 201007110, 201006901, 201006900, 201007014, 201007015, 201007019, 201007020, 201007022, 201007013, 201007113, 201006895, 201006946, 201006913, 201007100, 201006910 ; 108♀♀ 29♂♂, Dayanggou , Helan Mountain, Inner Mongolia, 27.VII.2010, Hongfei Chai, Nos. 201007246, 201007253, 201007262, 201007316, 201007391, 201007216, 201007397, 201007399, 201007404, 201007401, 201007396, 201007395, 201007394, 201007380, 201007388, 201007402, 201007406, 201007400, 201007389, 201007390, 201007418, 201007414, 201007332, 201007331, 201007430, 201007429, 201007431, 201007433, 201007435, 201007255, 201007282, 201007434, 201007387, 201007386, 201007385, 201007341, 201007343, 201007359, 201007357, 201007377, 201007344, 201007345, 201007333, 201007348, 201007360, 201007371, 201007378, 201007213, 201007265, 201007252, 201007312, 201007314, 201007315, 201007352, 201007330, 201007327, 201007326, 201007325, 201007324, 201007322, 201007321, 201007318, 201007363, 201007317, 201007335, 201007307, 201007306, 201007303, 201007302, 201007301, 201007299, 201007297, 201007296, 201007293, 201007287, 201007283, 201007284, 201007278, 201007275, 201007272, 201007271, 201007270, 201007267, 201007264, 201007261, 201007257, 201007251, 201007249, 201007245, 201007244, 201007243, 201007242, 201007239, 201007235, 201007234, 201007229, 201007228, 201007227, 201007208, 201007205, 201007206, 201007209, 201007211, 201007212, 201007215, 201007392, 201007222, 201007204, 201007202, 201007201, 201007198, 201007200, 201007199, 201007196, 201007195, 201007194, 201007192, 201007191, 201007187, 201007186, 201007184, 201007185, 201007156, 201007160, 201007164, 201007162, 201007166, 201007169, 201007172, 201007176, 201007173, 201007174, 201007177, 201007179, 201007183, 201007420, 201007419 ; 1♀, Qianggangling , Helan Mountain, Inner Mongolia, 3.VIII.2010, Dingjie Zhang, No. 201006771 ; 1♀, Ganshuwan , Helan Mountain, Inner Mongolia, 9.VIII.2010, Yan Li, No. 201006663 .

Distribution.

China: Inner Mongolia; Afghanistan, Austria, Armenia, Azerbaijan, Belarus, Bosnia and Herzegovina, Croatia, Czech Republic, Denmark, Egypt, Estonia, Finland, France, Georgia, Germany, Hungary, Indonesia, Ireland, Italy, Japan, Kazakhstan, Kyrgyzstan, Korea, Latvia, Lithuania, Luxembourg, Macedonia, Mongolia, Montenegro, Netherlands, Poland, Romania, Russia, Serbia, Slovenia, Spain, Sweden, Switzerland, Tajikistan, Turkey, United Kingdom and Uzbekistan.

Notes.

Characters of the examined specimens from China are mostly in agreement with the description in William (1988), except the legs are lighter (mainly reddish-yellow in female or yellow in male) than what he described (mainly rufo-fulvous in female). Characters combining large inflexible hypopygium, the length of ovipositor with its sheath and the typical large external genitalia in males (Fig. 1k , 1 .5 × wider than width of hind femur), could be a useful way to distinguish S. falcatus from other related genera in China. We treated Sathon provisionally as a valid genus for the Chinese fauna, with only one distinguishable representative for now, though the size of genitalia varies in other Sathon species.

Figures

Figure 1. Sathon falcatus (Nees, 1834) (new record to China) a ♀, habitus, lateral view b ♂, habitus, lateral view c fore wing d hind wing e head, dorsal view f head, frontal view g antenna h metanotum i propodeum and terga I-III j mesosoma, dorsal view k male external genitalia l mesopleuron, lateral view. Scale line: 0.5 mm.