Helius pulcher ( Loew, 1850 )

Kania, Iwona, 2014, Subfamily Limoniinae Speiser, 1909 (Diptera, Limoniidae) from Baltic amber (Eocene): the genus Helius Lepeletier & Serville, 1828, Zootaxa 3814 (3), pp. 333-352 : 342-350

Helius pulcher ( Loew, 1850)

( Figs 7 A–C)

v*1850 Rhamphidia pulchra: Loew , p. 37

1856 Rhamphidia pulchra Loew : Giebel, p. 242

v1906 Rhamphidia pulchra Loew (Meunier) : Meunier, p. 358, p. 364, Pl. XII, fig. 3–4 v1906 Antocha succinea Meunier : Meunier, p. 358, 368, Pl. XII, fig. 8, 9 and 10 v1931 Helius pulcher (Meunier) [sic!]: Alexander, p. 42

1931 Rhamphidia pulchra (Meunier) : Alexander, p. 42

1931 Antocha succinea Meunier : Alexander, p.42

1985 Helius pulcher (Meunier) : Krzemiński, p. 116. fig. 8 (fig. after Meunier) 1993 Helius pulcher (Loew) : Krzemiński, p. 597, 598

1993 Helius pulcher (Loew) : Krzemiński, p. 599, Fig. 1–4 —redescription of the Loew holotype. 1994 Helius pulcher Loew : Evenhuis, p. 73.

Remarks. Loew (1850) mentioned that there are four species of the genus Rhamphidia he recognized among Baltic amber inclusions from Berendt’s collection. Of these, two were given names Rhamphidia pulchra and Rhamphidia minuta . Unfortunately, he only mentioned, that Rhamphidia pulchra differs from Rhamphidia minuta by longer rostrum and antennae. Later, Meunier (1906), proposed redescription of Rhamphidia pulchra , based on two other specimens (probably from Klebs collection—Königsberg, later Göttingen). Alexander (1906) transfered the species Rhamphidia pulchra sensu Meunier to the genus Helius and redescribed it based on the number of specimens, including one of the specimens formerly examined by Meunier (No. 235, from Klebs collection). Alexander proposed also to synonymize Antocha succinea Meunier, 1906 under Helius pulcher , after reexamination of Meunier's type and another specimen. Krzemiński (1985) stated that Loew (1850) characterization of two species is not sufficient to validate these names. Krzemiński (1985) subordinated the name Helius pulcher to Meunier, and give a short redescription of this species based on two specimens from the Museum of the Earth, PAS in Warsaw. Later, Krzemiński (1993) presented the diagnostic features and description of Helius pulcher (Loew) —here he corrected the authorships of the species name, based on the holotype (specimen examined by Loew) from the Berendt's collection deposited in Palaeontological Institute of Humboldt University in Berlin, and another specimen from the same collection. It must be noted, that Krzemiński (1993) pointed that Meunier (1906) designated the wrong specimen for his redescription of Rhamphidia pulchra (i.e. Helius pulcher in modern system), which resulted in further misinterpretations. Regarding the status of Antocha succinea Meunier, 1906 — Krzemiński (1993) proposed to synonymize it under Helius minutus ( Loew, 1850) . This statement was later followed by Evenhuis (1994), with no comment to Alexander (1931) opinion.

Material examined. Holotype: No. MB.J. 359 (male) Coll. Berendt, ( ZMHB); additional material: No. MB.J. 358 (female) Coll. Berendt, ( ZMHB).

Diagnosistic characters. Male: rostrum approximately 1.2x the length of the head, shorter than antenna; antenna shorter than 1.5 of rostrum length (female) or at most twice as long as the rostrum (male); palpus 0.75x the length of the rostrum; outer gonostylus narrowing toward the tip and acutely pointed, slightly curved inwardly; vein r-m long, well expressed, cross-vein m-cu almost just distal of the base of fork of M1+2 and M3+4.

Redescription. Body: the length of specimens 5.66 mm (holotype, male), 7.79 (female).

Head ( Fig. 7 A). Male: antenna 16-segmented, short, slightly longer than the rostrum, 0.88 mm long, longer than palpus ( Fig. 7 B), antennae of female shorter than those of male; Female: rostrum approximately 1.2x the length of the head, shorter than twice the head length; antenna only 1.75 times longer than the rostrum;

Male: antenna twice as long as the rostrum; scape long, cylindrical; pedicel broad, barrel-shaped; first flagellomere broad, barrel-shaped; first to seventh flagellomeres with single long setae, about 1.5 the length of the segments bearing them; flagellomeres eighth to thirteenth with three elongated setae each, the setae almost three times longer that the length of flagellomeres bearing them; the last flagellomere without long setae.

Palpus ( Fig. 7 A): Male: palpus 0.75x the length of the rostrum, the last palpal segment 1.5 the length of all the preceding one. Female: palpus 1.2x the length of the rostrum, the last palpal segment 1.16x the length of the all the preceding taken together.

Wing ( Fig. 7 C): wing 6 mm long and 1.69 mm wide (male), 7.62 mm long, 1.57 mm wide (female); pterostigma present, large and oval; vein Sc ending opposite the fork of Rs; cross-vein sc-r at the end of Sc; R1 ending at R2+3+4 midlength; r-r (R2) atrophied; R2+3+4 elongated; d-cell short and broad; d-cell closed, M3 longer than d-cell, shorter than half the length of R5; cross-vein m-cu just beyond the bifurcation of Mb on M1+2 and M3+4; A1 and A2 rather long and straight.

Hypopygium: outer gonostylus rather long, reaching almost 2/3 the length of inner gonostylus, broad basally, narrowing gradually toward the end, acutely pointed and slightly curved to the inside in its 2/3 length. Inner gonostylus broad, strongly curved inside.

Ovipositor: long and narrow.

Helius similis sp. nov. ( Figs 8 A–C)

Material examined. Holotype: No. 3413 (male) ( SNMG); additional material: No. MP/3343 (male); No. MP/3344 (male) ( ISZP); No. 940.3 (male) Coll. Ch. and H. W. Hoffeins ( SDEI).

Diagnosis. Rostrum approximately as long as the head, shorter than palpus and antenna; antenna three times as long as the rostrum, palpus almost 1.2x the length of the rostrum; the last palpal segment shorter than all the preceding taken together; vein r-m rather long, well expressed, cross-vein m-cu in proximal 1/3 of d-cell base.

Etymology. From Latin similis , similar. The species epithet is adjective.

Description. Body: the length of specimens 3.88–4.42 mm (holotype).

Head ( Figs 8 A, 10B): rostrum 0.31mm – 0.42 mm (hototype), approximately as long as the head ( Fig. 8 B); antenna 16-segmented, 0.95 mm long, elongated, three times as long as rostrum; scape and pedicel barrel-shaped, large, its distal part conspicuously widened; pedicel very wide; first flagellomere barrel-shaped, flagellomeres 2–16 cylindrical, rather short; the last segment slightly shorter than penultimate one, dainty; flagellomeres with four elongated setae, the same length or slightly longer than the length of flagellomeres bearing them; the last one short, shorter than other flagellomeres, with three setae at apex.

Palpus ( Fig. 8 A): 0.38 mm; the length of last palpal segment 0.15 mm, penultimate 0.07 mm, first and the second segments 0.08 mm; the last palpal segment elongated but shorter than all the preceding taken together, twice as long as penultimate one.

Wing ( Fig. 8 C): wing 3.82–4.64 mm long and 0.76 mm wide; pterostigma absent; vein Sc elongated, ending opposite midlength of Rs; cross-vein sc-r proximad of the end of Sc; R1 short, ending approximately at the level of ¼ of R2+3+4 length; r-r (R2) atrophied; R2+3+4 elongated rather straight; d-cell closed not very broad, rather small; M3 twice longer than d-cell, M3 longer than half the length of R5; cross-vein m-cu in the proximal 1/3 of d-cell base; A1 and A2 elongated, slightly subsinuous.

Hypopygium: 0-38- 0.54 mm long; gonocoxite elongated and rather narrow, inner gonostylus narrowed in the distal part, wide at the base, shorter than half the length of gonocoxite; outer gonostylus not well visible.

Remarks. The species is similar to H. minutus in having comparatively short rostrum. In the new species rostrum is shorter than in H. minutus , approximately as long as the head. Also the new species differs in ratios of rostrum and palpus lengths. In H. similis sp. nov. rostrum is shorter than palpus and shorter than the half length of antenna (about 1/3 the length of antenna), in H. minutus rostrum is rather equal to palpus and approximately half the length of antennae. In H. similis in contrast to H. minutus wing is without pterostigma.

Figures

FIGURE 1. Helius longirostris (Meigen, 1818), type species.

FIGURE 2. Helius formosus Krzemiński 1993, No. 225 (female), holotype; A, head; B, relation between the length of palpi (p), antenna (a), rostrum (r) and head (h); C, wing venation.

FIGURE 3. Helius fossilis sp. nov. No. 587 (RS 64) (male); A, head; B, relation between the length of palpus (p), antenna (a), rostrum (r) and head (h); C, wing venation.

FIGURE 4. Helius gedanicus sp. nov., No. 4073 (male); A, head; B, relation between the length of palpus (p), antenna (a), rostrum (r) and head (h).

FIGURE 7. Helius pulcher Loew, 1850, No. MB. J. 358 (female) A, head; B, relation between the length of palpus (p), antenna (a), rostrum (r) and head (h); C, wing venation.

FIGURE 8. Helius similis sp. nov., No. 3413 (male); A, head; B, relation between the length of palpus (p), antenna (a), rostrum (r) and head (h); C, wing venation.