Amphithectus coriaceus, Paretas-Martínez & Pujade-Villar, 2013

Paretas-Martínez, Jordi & Pujade-Villar, Juli, 2013, Review of Amphithectus Hartig, 1840 (Hymenoptera: Cynipoidea: Figitidae: Figitinae), with description of Amphithectus coriaceus n. sp., Zoosystema 35 (2), pp. 183-194 : 188-192

Amphithectus coriaceus n. sp.

( Fig. 2 )

TYPE MATERIAL. — Holotype ♀ ( MNHN) with the following labels: “Reichenau, 1 juill.” (handwritten), “Muséum Paris, Amphitectus dahlbomii Coll. Giraud ” (white label), “ Holotype Amphithectus coriaceus ♀ Paretas-Martínez & Pujade-Villar n. sp. design. JP-V-2012” (red label).

ETYMOLOGY. — The specific name coriaceus (Latin) refers to the diagnostic character of this new species, the fine coriaceous sculpture in the head and mesoscutum.

DISTRIBUTION. — Germany.

DIAGNOSIS. — Amphithectus coriaceus n. sp. is distinguished from A. areolatus having coriaceous sculpture on head and mesoscutum ( Fig. 2 A-D), notauli completely defined and deep (wider in basal half; see Fig. 2B ), and interfoveal carina long, extending till half scutellum (arrow in Fig. 2B ).

DESCRIPTION

Length

Female: 3.75 mm. Male: unknown.

Head ( Fig. 2A, C )

Surface coriaceous ( Fig.2A, C ). Short setae uniformly distributed on frons, vertex and occiput, sparse on face. Area below each torulus clearly wrinkled. Clypeopleurostomal lines deep, strongly marked.

Antenna

Female 13-segmented; antennal formula: 6: 3(3): 6.5(x 2): 5.5(x 2.3): 5.5(x 2.6): 5: 5: 5: 5: 5: 5: 4.5: 4.5: 8. Placoid sensilla beginning on F3.

Forewings

Radial cell 2.5 times as long as wide.

Mesosoma ( Fig. 2 B-E)

Pubescence: all mesosoma covered with uniformly distributed short setae, but not densely. Pronotum: lateral areas of pronotum coriaceus, without carinae. Mesoscutum:completely coriaceus;notauli complete, deeper and wider in basal half; parapsidal lines clearly seen but superficial; antero-admedian lines clearly seen but superficial, reaching anterior one-third of mesoscutum; median mesoscutal impression deep but short, not reaching basal one-third of mesoscutum. Scutellum: interfoveal carina long, extending till half scutellum.

Biology

Unknown.

REMARKS

One specimen collected by Giraud in Reichenau ( Germany) and determined as A. dahlbomi ( Giraud 1860: 53) is the holotype of A. coriaceus n. sp.; the other three specimens are true A. areolatus .

Amphithectus areolatus ( Hartig, 1840) ( Fig. 3 )

Sarothrus areolatus Hartig, 1840: 203 , male.

Amphithectus dahlbohmii Hartig, 1840: 203 , female, specific name misspelling (species dedicated to Dahlbom, not Dahlbohm), lapsus calami. Synonymised by Reinhard (1860: 227).

Amphitectus piceus – Dahlbom 1842: 6 nomen nudum.

Amphitectus dahlbomi – Giraud 1860: 53.

Amphithectus dahlbomii – Reinhard 1860: 227. Incorrect subsequent spelling.

Melanips fumipennis Giraud, 1860: 43 , male. — Synonymised by Reinhard 1860: 227.

TYPE MATERIAL. — Sarothrus areolatus Hartig, 1840 : lectotype ♀ (deposited in ZSM) with the following labels: “201”, “Golden triangle”, “1”, “leg. Prof. Leunis Hildesheim” (handwritten), “ Lectotype Sarothrus areolatus Hartig, 1840 , det. 1980 M. Sotherlung” (red label), “ Lectotype ” (round label blue in margin), “ Lectotype of Sarothrus areolatus , det. N. D. M. Fergusson, 1983” (white label), Amphitectus areolatus Hartig, 1840 , Paretas- Martínez & Pujade-Villar det-2012” (white label).

Amphitectus dahlbomi Hartig, 1840 : lectotype ♀ (deposited in ZSM) with the following labels: “Golden triangle”, “Weld, 1931” (red label), “Voralpe und Steiermark, leg. Karsch” (handwritten), “4”, “ Lectotype ” (round label blue in margin), “ Lectotype of Amphitectus dahlbomii , det. N. D. M. Fergusson, 1983” (white label), “= Sarothrus areolatus , det. N. D. M. Fergusson, 1983” (white label), “ Amphitectus areolatus Hartig, 1840 , Paretas-Martínez & Pujade-Villar det-2012” (white label). Paralectotype ♀ (deposited in ZSM, non conspecific) with the following labels: “ Amphitectus dahlbohmii Hart. ” (handwritten), “ Paralectotype ” (round blue label in margin), “ Amphitectus dahlbomii ”= Sarothrus areolatus , det. N. D. M. Fergusson, 1983, Paralectotype ” (white label), “ Amphitectus sp , Paretas-Martínez det-2012” (white label).

Melanips fumipennis Giraud, 1860 : holotype ♂ (deposited in MNHN) with the following labels: “Salzb.” (handwritten), “ Saroth. areolatus ♀ H.” (handwritten), “ Melanips fumipennis, Gir. , ♂, A. dalbomii ” (handwritten), “Muséum Paris, Amphitectus dahlbomi Coll. Giraud ” (white label), “ Holotype ♂ Melanips fummipennis Giraud, 1860 ” (red label), “ Amphithectus areolatus ♂ Hartig, 1840 , Pujade-Villar det-2012” (white label).

ADDITIONAL MATERIAL. — 1♂, 3♀: 1♀ “Reichenau” (handwritten), “ Saroth. areolatus ♀ H.” (handwritten), “Muséum Paris, Amphitectus dahlbomi Coll. Giraud ” (white label), “ Amphithectus areolatus ♀ Hartig , Paretas- Martínez & Pujade-Villar det-2012” (white label) ; 1♀ “Muséum Paris, Amphitectus dahlbomi Coll. Giraud ” (white label), “ Amphithectus areolatus ♀ Hartig , Paretas- Martínez & Pujade-Villar det-2012” ; 1♂ & ♀ “gust.” (handwritten), “Muséum Paris, Amphitectus dahlbomi Coll. Giraud ” (white label), “ Amphithectus areolatus Hartig, Paretas-Martínez & Pujade-Villar det-2012” (white label) .

DISTRIBUTION. — Austria ( Hartig 1843: 419; Giraud 1860: 43). — Finland ( Hellén 1958: 58). — France ( Reinhard 1860: 228). — Germany ( Hartig 1840: 203; Giraud 1860: 53; Reinhard 1860: 228). — Holland and Switzerland ( Hellén 1958: 58). — Poland ( Hartig 1843: 419). — Russia ( Belizin 1928: 3). — Scandinavia ( Dahlbom 1842: 6). — Sweden (Thomson 1862: 417). — United Kingdom ( Cameron 1890: 168; Ferguson 1986: 27).

DIAGNOSIS. — Amphithectus areolatus Hartig, 1840 is distinguished from A. coriaceus n. sp. lacking coriaceous sculpture ( Fig. 3A, B ), having notauli not completely defined, only clearly seen superficially in basal half ( Fig. 3B ), and interfoveal carina not extending till half scutellum ( Fig. 3B ).

NOTE According to the article 33.3.1 of the ICZN for “Incorrect subsequent spellings” and 33.4 for “Use of - i for - ii and vice versa”, after corrections of Reinhard (1960) – dahlbomii – and Giraud (1960) – dahlbomi – and following authors spelling ( dahlbomi as Thomson [1862]; Cameron [1890]; Kieffer [1902], among others), the correct name of Amphithectus dahlbohmii is Amphithectus dahlbomi .

REDESCRIPTION

Length

Female: 4.4-4.6 mm. Male: 3.3-3.5 mm.

Head ( Fig. 3A )

Surface smooth, with uniformly distributed short setae on all areas. Area below each torulus not wrinkled or if so, very slightly. Clypeopleurostomal lines not strong, but clearly marked by a change of curvature on surface.

Antenna

Female:13-segmented, antennal formula:9: 2.5(x 2): 5.5(x 1.5): 4.5(x 2): 4.5: 4.5: 4.5: 4.5: 4: 4: 4: 4: 8. Placoid sensilla beginning on F2.Male:14-segmented, antennal formula: 5: 2(x 2): 6.5(x 2.4): 5.5: 6: 6: 6: 6: 5: 5: 5. 5. 5. 9. Placoid sensilla beginning on F1. F1 very few modified, weakly excavate ( Fig. 3C ).

Forewings

Radial cell 2.5 times as long as wide.

Mesosoma ( Fig. 3B )

Pubescence: pronotum and propodeum with uniformly distributed short setae, but not densely; mesoscutum with sparse setae. Pronotum: lateral areas smooth, without carinae.Mesoscutum:smooth, with piliferous points; notauli incomplete, only superficially seen in basal half; parapsidal and anteroadmedian lines absent; median mesoscutal impression only slightly marked. Scutellum: interfoveal carina not extending till half scutellum.

Biology According to Ferguson (1986: 27) the hosts are Pegohylemyia gnava (Meigen,1826) and Pegohylemyia sonchi (Hardy, 1872) ( Diptera : Anthomyiidae ). Previously, Reinhard (1860: 228) comments:“in July and August both sexes are often collected together on Umbelliferae”.

REMARKS

The paralectotype of A. dahlbomi (♀, ZSM) lacks the head. This specimen may belong to a different species than the lectotype, because notauli are completely defined and more complete.We consider this specimen not belonging to A. coriaceus , because the mesoscutum is smooth with piliferous points (not coriaceous) neither belonging to A. areolatus because the notauli are complete ( Fig. 4F ), but we cannot describe a new species without the head ( Fig. 4E ).

DISCUSSION

As for many small-bodied Hymenoptera , cynipoid biodiversity is certainly under-estimated, and much remains to be learned of their systematics. This lack of knowledge is particularly acute in several figitid subfamilies, among them the Figitinae with several genera known only from the type species. Until now, Amphithectus was only known from the type species A. areolatus . Here we redescribe A. areolatus , and describe A. coriaceus n. sp., which is characterised by having fine coriaceous sculpture. This new species has the same female metasomal morphology as A. areolatus . The female metasoma of Amphithectus is very different from that of Sarothrus , genus to which Amphithectus has been previously considered as synonym ( Reinhard 1860; Kieffer 1902; Dalla Torre & Kieffer 1910; Weld 1952; Fergusson 1986). Metasomal morphology is a very important character within Figitidae in order to distinguish different genera and even different subfamilies. Among Figitidae , two species of a same genus always have the same metasomal morphology. Nevertheless, in Trybliographa Förster, 1869 ( Figitinae : Eucoilinae ) is one particular species-group, the “ melanoptera group” has a similar hypertrophy of the female metasoma as Amphithectus has (Forshage pers.com.). The shape in Amphithectus could be an apomorphic hypertrophy (probably to facilitate housing a much longer ovipositor, or possibly to be able to insert the entire metasoma into some narrow space during oviposition) derived from a more plesiomorphic state in other Sarothrus (Forshage pers. com.). However, Forshage (pers. com.) considers that this character is important enough to consider Amphithectus as a valid genus separated from Sarothrus because both genera can also be distinguished by the wing coloration and the facial sculpture (these characters useful in both sexes).

According to Pujade-Villar et al. (2013), the morphological revisions of Amphithectus and Sarothrus (in process) are needed to make a phylogenetic study of the Figitinae + Aspicerinae including all genera of both subfamilies in order to elucidate the placement and relationships of genera with very “particular” morphology like Lonchidia , Melanips , Nebulovena , Ferpereira , Amphithectus and Sarothrus .

Figures

FIG. 2. — Amphithectus coriaceus n. sp.: A, head, anterior view; B, mesosoma, dorsal view (arrow indicates long interfoveal carina); C, head posterior view, and pronotal plate dorsal view; D, mesoscutum, detail of coriaceous sculpture; E, habitus ♀. Scale bar: 1 mm.

FIG. 3. — Amphithectus areolatus Hartig, 1840 (= A. dahlbomi Hartig). A, head, anterior view; B, mesosoma, dorsal view; C, F1-F3 ♂, dorsal view; D, ♂, dorsal view of scutellum+metasoma; E, forewing and radial cell; F, T2-T3 ♀, lateral view. Scale bar: 1 mm.

FIG. 4. — Diagnostic characters of Amphithectus and Sarothrus (A-D) and paralectotype not conspecific of A. dahlbomi (E,F): A, head in anterior view of A. areolatus; B, head in anterior view of S. tibialis; C, forewing of A. areolatus; D, forewing of S. tibialis; E, habitus of paralectotype not conspecific of A. areolatus (= A. dahlbomi Hartig); F, detail of anterior part of mesosoma of paralectotype not conspecific of A. areolatus.