A review of world Diallactiini (Diptera, Cecidomyiidae, Winnertziinae), with the description of six new genera and seventeen new species
Author
Jaschhof, Mathias
text
Zootaxa
2016
4127
2
201
244
journal article
38748
10.11646/zootaxa.4127.2.1
55d0500c-80bd-4fa2-8ea1-39c0f251edb9
1175-5326
267022
B2590AFB-62BF-4D53-98E9-3358AB616413
Genus
Johnsonomyia
Felt, 1908
stat. rest.
Johnsonomyia
—
Felt 1908
: 417
.
Type
species,
rubra
Felt
, by original designation.—
Mamaev 1964
: 902
(as junior synonym of
Chastomera
Skuse
);
Panelius 1965
: 17
(listed as distinct from
Chastomera
Skuse
);
Mamaev 1966
: 218
(altered diagnosis, new species);
Parnell 1971
: 281
(review, key to Nearctic species);
Gagné 1978
: 517
(as junior synonym of
Haplusia
Karsch
, discussion);
Spungis 1985
: 47
(discussion, diagnosis, description of Latvian species);
Jaschhof & Jaschhof 2013
: 59
(as junior synonym of
Haplusia
Karsch
, discussion).
Species of
Johnsonomyia
:
alexanderi
Felt, 1921
. Afrotropical.
funebris
(
Plakidas, 2007
)
[
Haplusia
]. New combination. Nearctic.
fusca
Felt, 1908
. Nearctic.
lobata
(
Yukawa, 1968
)
[
Wyattella
]. New combination. Oriental.
palpata
Mamaev, 1966
. Palearctic.
rubra
Felt 1908
. Nearctic.
scabra
Jaschhof
sp. nov.
, described below. Neotropical.
serrata
Jaschhof
sp. nov.
, described below. Afrotropical.
spiculosa
(
Barnes, 1927
)
[
Chastomera
]. Oriental.
Seventeen unnamed species from the Neotropical, Afrotropical, Oriental, and Australasian regions.
Felt (1908)
introduced the genus
Johnsonomyia
for three Nearctic species, of which one,
J. humilis
, was misplaced in this genus and later (
Parnell 1971
) assigned to
Holoneurus
Kieffer,
1894
in
Porricondylinae
, where it provisionally resides (
Gagné & Jaschhof 2014
); the other two species,
J. fusca
and
J. rubra
, are dealt with below. Felt used solely wing characters for differentiating
Johnsonomyia
from the other six genera of his Epidosariae, a taxon nearly equivalent to the modern Winnertziinae and
Porricondylinae
combined. Two other
Johnsonomyia
that he described in later years (
Felt 1912
,
1915
) fall under my concept of
Haplusia
(see there). The name
Johnsonomyia
was taken up by
Mamaev (1966)
to denote
Diallactiini
whose eye bridge covers the entire dorsal head surface, irrespective of the fact that
J. rubra
, the
type
species, does not meet this condition. Mamaev’s redefinition of
Johnsonomyia
, though inappropriate, was followed by subsequent authors, such as
Parnell (1971)
and
Spungis (1985)
.
Gagné (1978)
disputed the merit of eye bridge length for distinguishing diallactiine genera and, led by similarities in venation and general habitus, regarded
Johnsonomyia
as synonymous with
Haplusia
and
Chastomera
. I studied the male
holotype
of
J. rubra
and specimens of several other, similar species and came to the conclusion that
Johnsonomyia
should be treated as a genus distinct from
Haplusia
(see Diagnosis) but in a sense that differs from
Mamaev (1966)
. The basis of my concept of
Johnsonomyia
is supported by characters of the
type
species,
J. rubra
.
Nevertheless,
Johnsonomyia
, as here understood, is no unproblematic group. Its morphology is diverse and, consequently, difficult to condense in a straightforward diagnosis. A possible explanation for this may be that the group as delimited here is not monophyletic. Indeed, among the
Johnsonomyia
species I have seen (which are few compared with the many species that I suppose are yet uncollected) I identified two presumably natural subgroups, each with two respectively four species, which one could regard as possible candidates for discrete genera. It is beyond the scope of this paper to treat these subgroups in detail. Even
J. rubra
is in some way different from other
Johnsonomyia
. Contributing to the problem,
Johnsonomyia
appears to have many species in the tropics, which in my experience feature—more often than species in temperate regions—strange characters and character combinations. This phenomenon, which I have observed also in mycophagous cecidomyiids other than
Johnsonomyia
, complicates the task of identification, especially when those somehow aberrant species are the only fragments known of an otherwise unexplored fauna. It is likely that my present definition of
Johnsonomyia
will need to be reappraised with further knowledge of the world species. I have seen specimens of unnamed
Johnsonomyia
from
Costa Rica
(7 species),
South Africa
(2 species),
Brunei
(6 species), peninsular
Malaysia
(1 species), and
New Zealand
(1 species). This renders the genus cosmopolitan in distribution.
Most of the species assigned here to
Johnsonomyia
were described on the basis of only one sex, usually the male. With respect to preimagines,
Spungis (1985)
described larvae of
H. palpata
and
Plakidas (2007)
described both larvae and pupae of
H. funebris
.
Diagnosis.
Johnsonomyia
and
Haplusia
, which resemble each other in many respects, are distinguished as follows. Species of
Johnsonomyia
lack the striking coloration of
Haplusia
, so have much less white and much less striking color patterns. Antennae are brownish rather than white; wings are never milky white but are brownish to grayish, often with the Rs, but never the CuA, darkened; and if legs are bicolored, then in a way that tarsi are lighter than other segments, without any banding. The eye bridge is on average shorter, typically 4–7 (in an unnamed Costa Rican species 2–3) ommatidia long dorsally; palpi, which are usually 4-segmented, have in some species always 3 segments (in even other species a varying 3 or 4 segments); the scape is usually setose, rarely unsetose; the pedicel, usually unsetose, has 1 or 2 setae in a few species; flagellomere nodes have either a whorl of setae subbasally or irregular setae intermingled with translucent sensilla, and microtrichia usually only basally but sometimes everywhere; thoracal sclerites other than scutum and scutellum are usually unsetose, but an unnamed Costa Rican species has a setose anepisternum; wing length / width is 2.6–2.9; and basitarsi, which never bear a spine, have in some species a small, subtriangular, microtrichose or glabrous lobe. As regards male genitalia, the ventral gonocoxal emargination is multiform; the ventral gonocoxal bridge may have a faint transverse suture; the gonostylus is toothed in most species but untoothed in
J. funebris
and an unnamed species from
Brunei
; and tegmina are poorly to moderately sclerotized, subtriangular to elongate-subtrapezoid, usually rounded apically, and occasionally with slightly serrate edges or granulated surfaces.