Subfamily Limoniinae Speiser, 1909 (Diptera, Limoniidae) from Baltic amber (Eocene): the genus Helius Lepeletier & Serville, 1828AuthorKania, IwonatextZootaxa201438143333352journal article4554010.11646/zootaxa.3814.3.2708ea530-4c8d-473b-8f29-1a54dea92f281175-53262311075391C375-896D-4794-84A6-1846DF9E407DHelius pulcher
(
Loew, 1850
)
(
Figs 7
A–C)
v*1850
Rhamphidia pulchra
: Loew
, p. 37
1856
Rhamphidia pulchra
Loew
: Giebel, p. 242
v1906Rhamphidia pulchra
Loew (Meunier)
: Meunier, p. 358, p. 364, Pl. XII, fig.
3–4 v1906Antocha succinea
Meunier
: Meunier, p. 358, 368, Pl. XII, fig. 8,
9 and 10 v1931Helius 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 succineaMeunier, 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 succineaMeunier, 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.
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.
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 similissp. 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.
FIGURE 8.
Helius similissp. nov.
, No. 3413 (male); A, head; B, relation between the length of palpus (p), antenna (a), rostrum (r) and head (h); C, wing venation.
FIGURE 9.
Relation between the length of palpus (p), antenna (a), rostrum (r) and head (h) in different fossil species known from Baltic amber.
FIGURE 10.
Morphology of
Helius
from Baltic amber. A
H. hoffeinsorumsp. nov.
, No. 1462 (male), holotype, the body, lateral view; B.
H. similissp. nov.
, No. 3413 (male) head and thorax latero-ventral view, C–D.
H. minutus
Loew, 1850
, No. 7895 (male), neotype, C. antennae, palpi, rostrum, D. head.
FIGURE 11.
Morphology of
Helius
from Baltic amber. A–B
H. fossilissp. nov.
, No. 587 (RS64) (male), holotype, A. the body, lateral view; B. head, lateral view C.
H. hoffeinsorumsp. nov.
, No. 1462 (male), hypopygium; D–E
H. formosus
Krzemiński, 1993
, No. 225 (female), holotype, D. antennae, E. wing. Abbreviation of male hypopygium: gx—gonocoxite, ing—inner gonostylus, oug—outer gonostylus, aed—aedeagus, p—paramere.
FIGURE 12.
Scanning electron microphotographs of
Helius flavus
(Walker, 1856)
(female). A. the distal part of rostrum with nasus and palpi visible; B. the last palpal segment; C. the apical part of the last palpal segment with microtrichia. Abbreviation: R—rostrum; NS—nasus; P—palpi; MI—microtrichia; ES—elongated setae.
FIGURE 13.
Morphology of palpi of recent and fossil
Helius
. A–D
Helius flavus
(Walker, 1856)
; E–F.
Helius fossilissp. nov.
Abbreviation: I–IV –segments of palpi; MI—microtrichia; ES—elongated setae.
FIGURE 14.
Morphology of antennae of
recent
Helius flavus
(Walker, 1856) (female).
A scape and pedicel; B. first
flagellomeres. Abbreviation: SCP—scape;
PD—pedicel; III–IV
segments of flagellum;
MI—microtrichia; sc—sensilla
coeloconica (?).
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. similissp. 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.