Trissolcus darreh Talamas, 2021

Ranjbar, Fateme, Jalali, M. Amin, Ziaaddini, Mahdi, Gholamalizade, Zahra & Talamas, Elijah J., 2021, Stink bug egg parasitoids (Hymenoptera, Scelionidae) associated with pistachio in Iran and description of a new species: Trissolcus darreh Talamas, Journal of Hymenoptera Research 87, pp. 291-308 : 291

Trissolcus darreh Talamas sp. nov.

Description.

Female body length: 0.93-1.17 mm (n = 24). Male body length: 0.92-1.02 mm (n = 6).

Antenna. Color of radicle: yellow. Length of radicle: less than width of clypeus. Color of A1-A6 in female: variably yellow to brown. Color of A7-A11 in female: brown to black. Claval formula: 1-2-2-2-2.

Head. Facial striae: absent. Number of clypeal setae: 2. Shape of gena in lateral view: narrow. Genal carina: absent. Malar striae: absent. Sculpture of malar sulcus: unknown. Orbital furrow: constricted or poorly defined ventrally. Macrosculpture directly dorsal to the antennal scrobe: absent. Preocellar pit: present. Setation of lateral frons: moderately dense. Punctation of lateral frons: absent. Sculpture directly ventral to preocellar pit: smooth. Rugae on lateral frons: absent. OOL: less than one ocellar diameter. Hyperoccipital carina: present, weakened medially. Macrosculpture of posterior vertex: absent. Microsculpture on posterior vertex along occipital carina: coriaceous. Anterior margin of occipital carina: crenulate. Medial part of occipital carina in dorsal view: rounded.

Mesosoma. Epomial carina: present. Macrosculpture of lateral pronotum directly anterior to netrion: finely rugulose. Netrion sulcus: incomplete, not well-defined dorsally. Pronotal suprahumeral sulcus in posterior half of pronotum: undifferentiated from sculpture of dorsal pronotum. Number of episternal foveae: 0; 1; 2. Course of episternal foveae ventrally: distinctly separate from postacetabular sulcus. Course of episternal foveae dorsally: distinctly separate from mesopleural pit. Subacropleural sulcus: present. Speculum: transversely strigose; smooth. Mesopleural pit: extending ventrally into slender, shallow furrow. Mesopleural carina: absent. Sculpture of femoral depression: smooth. Patch of striae at posteroventral end of femoral depression: absent; indicated by lines of microsculpture. Setal patch at posteroventral end of femoral depression: present as a line of setae. Microsculpture of anteroventral mesopleuron: present only on anterior face of mesopleuron bulge. Macrosculpture of anteroventral mesopleuron: absent. Postacetabular sulcus: comprised of small crenulae. Mesopleural epicoxal sulcus: present as a smooth furrow. Setation of posteroventral metapleuron: absent. Sculpture of dorsal metapleural area: absent. Posterodorsal metapleural sulcus: present as a line of foveae. Paracoxal sulcus in ventral half of metapleuron: absent. Length of anteroventral extension of metapleuron: short, not extending to base of mesocoxa. Apex of anteroventral extension of metapleuron: acute. Metapleural epicoxal sulcus: present as coarse rugae. Mesoscutal humeral sulcus: present as a simple furrow. Median mesoscutal carina: absent. Microsculpture of mesoscutum: granular throughout. Mesoscutal suprahumeral sulcus: comprised of foveae. Length of mesoscutal suprahumeral sulcus: two-thirds the length of anterolateral edge of mesoscutum. Parapsidal line: present. Notaulus: present. Median protuberance on anterior margin of mesoscutellum: absent. Shape of dorsal margin of anterior lobe of axillar crescent: unknown. Sculpture of anterior lobe of axillar crescent: dorsoventrally strigose. Area bound by axillar crescent: smooth. Macrosculpture of mesoscutellum: absent. Microsculpture on mesoscutellum: unknown. Median mesoscutellar carina: absent. Setation of posterior scutellar sulcus: present. Form of metascutellum: single row of foveae along anterior margin, rugulose posteriorly. Metanotal trough: foveate, foveae occupying less than half of metanotal height. Metapostnotum: invaginated near lateral edge of metascutellum. Anteromedial portion of metasomal depression: smooth.

Wings. Length of postmarginal vein: about 1.5 times as long as stigmal vein. Color of setae on fore wing: white throughout, brown at distal end.

Legs. Color of legs: coxae and femora dark brown to black, otherwise pale brown to yellow. Anteroventral area of hind femora: not covered by setae.

Metasoma. Width of metasoma: about equal to width of mesosoma. Number of sublateral setae (on one side): 0. Setation of laterotergite 1: absent. Length of striation on T2: extending two-thirds the length of the tergite. Setation of T2: present only in posterolateral corner. Setation of laterotergite 2: present.

Material examined.

Rafsanjan, Kerman Prov., Iran, 2019; Holotype female (FSCA 00095713, deposited in FSCA) reared from eggs of Acrosternum arabicum ; Paratypes: 32 females, 6 males: FSCA 00090925, 00093783-00093784, 00093788, 00093793, 00093798, 00093805, 00093832, 00093842, 00093845, 00093854, 00094227-00094228, 00094230-00094232, 00094235-00094236, 00094238-00094240, 00094242, 00094246-00094247, 00094254-00094255, 00094265, 00094267, 00094269, 00094275, 00094878, 00095711-00095712, 00095760 reared from eggs of Acrosternum arabicum ; FSCA 00094248, 00094273, 00095759 reared from eggs of Brachynema signatum .

Intraspecific variation.

In the specimens reared from B. signatum , the mesopleuron directly ventral to the femoral depression projects more sharply than in the specimens reared from A. arabicum . However, because we have only three females and one male reared from B. signatum , more specimens are needed to confirm that this difference is host related. Other characters with notable variation are the orbital furrow, the hyperoccipital carina, the color of setae on the fore wing and subtle differences in the episternal foveae. In females, the orbital furrow tends to become constricted ventrally, but in some specimens the medial edge of the furrow is not defined where it intersects the malar sulcus. This condition was typical for the small number of males that we examined. The hyperoccipital carina is medially weakened in all specimens and in some it is essentially absent between the lateral ocelli. Variation in the color of the wing setae can be difficult to assess without slide-mounting the wings because the perception of the color is influenced by what is behind the wing, and the color difference is subtle. However, it should still be noted that setae at the apex of the fore wing appear to vary from pale to medium brown. The episternal foveae in T. darreh are shallow and may be irregular in shape. In most specimens, there is a single fovea, but occasionally there are two. Rarely, and usually in males, no foveae are visible.

Comments.

Trissolcus darreh arrives at couplet 16 in the key to Trissolcus species of the Palearctic region by Talamas et al. (2017), where it matches neither of the leads, having neither a continuous line of episternal foveae between the postacetabular sulcus and mesopleural pit, nor abbreviated notauli. It is similar to Trissolcus saakowi , which has been recorded from Iran, but these species can be separated by the setation of the first laterotergite: present in T. saakowi and absent in T. darreh . Trissolcus darreh is also similar to T. tumidus , with which it shares the medially weakened hyperoccipital carina and the reduced episternal foveae. However, these two species are easily separated by the orbital furrow, being well defined at the intersection with the malar sulcus in T. tumidus , and the form of the mesoscutal humeral sulcus, which is a smooth furrow in T. darreh and is comprised of foveae in T. tumidus .

COI barcoding.

Multiple attempts were made to amplify COI from specimens of T. darreh and from one specimen we were able to produce a faint band with LepF1/LepR1 primers. Sequencing produced a quality read in only in the forward direction, precluding us from uploading it to GenBank, which requires bidirectional sequencing. This sequence is unique in BOLD and GenBank. The closest match in GenBank is to Trissolcus euschisti (Ashmead) (MG939339.1, 84% sequence identity). In BOLD, the best matches are all ~89.5% to BINs BOLD:AAZ3289 ( Telenomus Haliday), BOLD:ACB8142 ( Trissolcus ), and BOLD:ACB8142 ( Phanuromyia Dodd). Identification of the latter two BINs was made based on images provided in BOLD. A FASTA file of this sequence is provided in Suppl. material 1.

Etymology.

This species is given the name " Trissolcus darreh ," a Farsi word for valley, because the form of the orbital furrow is one of its diagnostic characters.