Drilus iljini Barovskij, 1922

Packova, Gabriela, Hoffmannova, Johana & Kundrata, Robin, 2021, Drilini (Coleoptera: Elateridae: Agrypninae) of Iran, The Coleopterists Bulletin 75 (3), pp. 579-586 : 582-583

Drilus iljini Barovskij, 1922

( Fig. 4 )

Drilus iljini Barovskij 1922: 25 .

Type Locality. Iran: Gīlān prov., Hassankiadeh .

Type Material. Holotype, male, “Persia septentrionalis [ North Iran]: Hassan-Kiadeh (B. Iljin 27. IV. 1916 leg.)” (coll. Barovskij, ZIN?) ( Barovskij 1922). The type specimen has not been located at the ZIN collection (M. G. Volkovitsh and A. Kovalev, personal communication).

Other Material Examined. 1 male, “N-IRAN, Pr. Mazandaran /N-Elburz, Now Shahr, Om / 36° 36’ 17”N, 51° 38’ 23”E / 6. V. 2012. leg. D. Frenzel ” ( NKME) ; 1 male, “N-IRAN, Pr. Mazandaran /NElburz, Now Shahr, Om / 36° 36’ 17”N, 51° 38’ 23”E / 6. V. 2012. leg. D. Frenzel ” ( NKME) ; 1 male, “ Iran, Mazandaran, 1400 m / 20 km südlich Nowshahr,/ Weysser , 9.–14. 6. 1977 /leg. Holzschuh & Ressl // D./ iljini /Barov.//Naturhistorisches/Museum Basel/ Coll. W. Wittmer ” ( NHMB) ; 1 male, “ ♂ // Persia/[unreadable data]//coll. Richard /Hicker, Wien//Naturhistorisches/Museum Basel/ Coll. W. Wittmer ” ( NHMB) ; 1 male, “ IRAN, Ardabil prov., 4.-5. VI. 2006 / 5 km NW KOLUR /” Shahrud ” river valley/ 37°26, 1’N 48° 41,2’E; 1670 m / Jiří Hájek & Pavel Chvojka leg.” ( NMPC). The following specimens were examined based only on photographs kindly provided by Dr. A. Kovalev ( ZIN) : 3 males, “Астрабад [Astrabad; = Gorgan]/13.IV.[19]14. [other two specimens: “24.IV.[19]14” and “2. V.[19]14”] [the dates in Russia before 1918 are in the Julian calendar, with the difference in the 20th century of 13 days compared to the Gregorian calendar, e.g., 13.IV.1914 is 26.IV.1914]/А. Кириченко [A. N. Kiritshenko]” ( ZIN) .

Comparison. This species differs from Drilorhinus klimenkoi in the dark brown to blackish head, pro- and mesothorax (yellowish to reddish brown in D. klimenkoi ), the short, widely concave frontoclypeal region (strongly projected forwards in D. klimenkoi ), the distinctly transverse pronotum, which is 1.6–1.8 times as wide as long (subtrapezoidal, 1.30–1.35 times as wide as long in D. klimenkoi ), and elytra adjacent to each other for almost their whole length (adjacent only at basal third, then divergent in D. klimenkoi ) ( Figs. 1–2 , 4 ). Drilus iljini differs from D. iranicus in the dark brown to blackish pronotum, hypomeron and scutellar shield (yellowish to reddish brown in D. iranicus ), pronotum widest at about middle (at posterior angles in D. iranicus ), and relatively slenderer parameres (more robust and relatively wider in D. iranicus ) ( Figs. 4–5 ).

Diagnostic Redescription. Body ( Fig. 4A ) 5.0– 7.2 mm long, 2.8–3.3 times as long as width at humeri. Body dark brown to black, antenna brown, with antennomeres I and II slightly lighter, mouthparts and legs yellowish brown to brown (femur and tibia darker, tarsus distinctly lighter), and apical abdominal segment yellowish brown.

Head ( Figs. 4B, C ) including eyes 0.70–0.80 times as wide as pronotum, frontoclypeal region between antennal insertions widely concave; eyes medium-sized, their frontal distance 1.95–2.35 times eye diameter; mandible moderately long and curved; antenna ( Fig. 4A ) pectinate, antennomere III subtriangular; antennomeres IV–X each with moderately long, slightly flattened branch, which is 1.00–1.25 times as long as its respective stem; antennomere XI approximately as twice as long as antennomere X.

Pronotum ( Figs. 4B, C ) transverse, widest around middle, 1.60–1.80 times as wide as long; sides more or less rounded, narrowed anteriorly; posterior angles subrectangular, apically rounded. Elytra ( Fig. 4A ) elongate, covering almost whole abdomen, adjacent to each other for almost whole length, both combined 2.05–2.45 times as long as wide, 0.70–0.75 times as long as body, 3.90–4.40 times as long as pronotum.

Abdominal sternite IX 1.90–1.95 times as long as wide. Male genitalia ( Fig. 4D ) 1.65–1.70 times as long as maximum phallobase width; median lobe elongate, 1.3 times as long as phallobase; paramere robust, without latero-apical projection, apically rounded, partly membranous; phallobase U-shaped, 1.15–1.20 as wide as long.

Female and immature stages unknown.

Variability. There is variability in the coloration of labrum and body appendages, i. e., antennae, palpi, and legs. In darker specimens they are brown, with only tarsi always being lighter, while in lighter specimens they are yellowish brown to light brown, with tarsi again lighter ( Figs. 4A–C ). Additionally, there is slight variability in the shape of the pronotum, especially the length/width ratio and the shape of the posterior angles ( Figs. 4A–C ), and in the relative length of the elytra compared to the pronotum.

Distribution. Iran (Ardabil, Gīlān and Mazandaran provinces).

Figures

Fig. 4. Drilus iljini, male.A) Habitus, dorsal view, B–C) Head and pronotum, dorsal view, D) Male genitalia, dorsal view. Scale bars = 2.0 mm (A), 0.5 mm (B, C), 0.3 mm (D).

Fig. 1. Drilorhinus klimenkoi, male. A–C) Habitus, dorsal, ventral and lateral view, respectively. Scale bars

Fig. 2. Drilorhinus klimenkoi, male. A–C) Head, dorsal, ventral and frontal view, respectively, D) Antenna, E–F) Pronotum, dorsal and lateral view. Scale bars = 0.5 mm (A–C, F), 1.0 mm (D, E).