New tribe Labiobaetini tribus n., redefinition of Pseudopannota Waltz & McCafferty 1987 and descriptions of new and little known species from Zambia and Uganda
Author
Kluge, Nikita J.
Author
Novikova, Eugenia A.
text
Zootaxa
2016
4169
1
1
43
journal article
10.11646/zootaxa.4169.1.1
1e9b4934-1b5a-42c1-93c4-386a0b1829a1
1175-5326
267393
F15C0038-DF14-4E4B-98F5-FE1BD7A5759F
Labiobaetis tenuicrinitus
(Kopelke1980)
comb. n.
(Figs 113–141)
Pseudocloeon tenuicrinitum
Kopelke 1980a
: 117
(
♂
imago);
Kopelke 1980b
: 304
(egg);
Kopelke 1981
: 16
(ecology); Lugo- Ortiz,
McCafferty & Waltz 1999
: 24
.
Baetis tenuicri
[
ni
]
tus
:
Gillies 1994
: 117
;
Baetis spatulatus
Gillies 1994
: 108
(
♂
imago, larva)
syn. n.
;
Gillies 1997
: 114
,
Fig. 2
D (tergalius);
Gillies 1999
: 53
.
Material
examined.
UGANDA
:
Kasese District
,
Kiburara
,
river Nyamagasan
,
8–13.VIII.2007
, coll.
N. Kluge
: 5 L-S-IƋ, 12 L-S-I
♀
, 2 L-SƋ
, 33 larvae.
Descriptions.
Larva.
CUTICULAR COLORATION. Dorsal side of head, thorax and abdomen ocher-brown, with lighter median stripe along all abdominal terga (Figs 116, 117). Legs unicolor light ocher. Cerci unicolor ocher-brown, paracercus lighter (Fig. 115). Tergalii light ocher.
HYPODERMAL COLORATION. On legs absent. On abdomen, if present, coincides with cuticular color pattern (Figs 113, 114).
STRUCTURE. Frons between antennae bases flat; frontal suture blunt-angled in female and acute-angled in male (
Figs 124, 125
). Scapus of antenna simple, without lateral-apical projection. Labrum with pair of branched submedian setae and with pair of arched latero-anterior rows of branched setae (
Fig. 122
). Mandibles with convex inner margin between prostheca and mola (
Fig. 4
;
Gillies 1994
:
Figs 17, 18
). Maxilla stout; second segment of maxillary palp thick, with shallow incision in distal part of median margin (
Fig. 123
). Hypopharynx without long apical spines (
Fig. 137
). Labium (
Figs 126, 127
): glossa with setae of medio-ventral row stout, subapical median seta much longer; paraglossae wide, with apical setae forming 3 rows; 2nd segment of labial palp with median projection wide and rounded.
Vestiges of hind protoptera present (
Fig. 128
). Legs stout, with short spine-like setae (
Fig. 133
). Outer side of femur with irregular row of short stout blunt setae; in proximal part of femur these setae often form more than one row; two most distal setae often attached close one to another. Apical margin of femur with minute stout blunt setae (
Fig. 135
). Inner side of femur with sparse minute stout blunt setae.
No
structures resembling femoral patch of Baetofemorata. Tibia flattened and widened; outer margin of tibia with irregular row of minute stout blunt setae; apex of tibia bears prominent outer-apical projection with one enlarged stout blunt seta (
Fig. 136
); inner side of tibia with two or more irregular longitudinal rows of stout pointed setae. Outer side of tarsus with irregular minute stout blunt setae; inner side of tarsus with one regular row of stout pointed setae. Claw hooked, with 11–14 denticles (
Fig. 132
).
FIGURES 113–117.
Labiobaetis tenuicrinitus
. 113, mature
|
male |
larva ready |
to molt to subimago |
(with |
cuticular |
and |
hypodermal pigmentation combined); 114, abdomen extracted |
from |
mature male |
larva; 115, caudalii of |
larval |
exuviae; |
116, |
117, larval exuviae of abdomen of two individuals. |
FIGURES 118–121.
Labiobaetis tenuicrinitus
. 118, female imago; 119, subimaginal exuviae of right half of mesonotum; 120, subimaginal exuviae of left pleurite with postsubalar sclerite and lateropostnotal crest; 121, male imago.
FIGURES 122–125.
Labiobaetis tenuicrinitus
, larva. 122, labrum, dorsal view; 123, left maxilla (muscle in 1st palpomere shown by interrupted lines); 124, frontal suture of female larva; 125, frontal suture of male larva. Abbreviations: 1, 2, segment of maxillary palp; ds1, ds2, ds3, dentisetae.
FIGURES 126–129.
Labiobaetis tenuicrinitus
, larva. 126, labium, ventral view (at left half, muscles shown by interrupted lines); 127, glossae and paraglossae (at left half, ventral view; at right half, dorsal view); 128, margin of ultimolarval metanotum with vestige of hind protopteron; 129, paraproct.
FIGURES 130–133.
Labiobaetis tenuicrinitus
. 130, subimaginal gonostyli folded under larval cuticle (1, 2, 3, segments of gonostylus); 131, genitals of male imago (at right half, muscles shown by interrupted lines; places of attachment of median paraproctal muscles shown by dotted lines; 1, 2, 3, segments of gonostylus); 132, larval claw; 133, larval fore leg, dorsal view. Abbreviations: gv, gonovectis; pgs, protogonostylus (paired convexity on posterior margin of IX sternum of male larva); mIX- X, areas of anterior attachment of median paraproctal muscles (i.e., muscles going from sternum IX to common base of paraprocts); pb, median projection of penial bridge; usg, unistyliger.
FIGURES 134–141.
Labiobaetis tenuicrinitus
. 134, tarsus of subimaginal middle leg; 135, apex of femur of larval leg; 136, apex of tibia of larval leg; 137, hypopharynx; 138, larval abdominal tergum VII; 139–141, eggs.
Abdominal segments II–IX with equally small, pointed, sclerotized posterolateral spines (Figs 116, 117). Surface of abdominal terga and sterna densely covered with scales in wide semicircular sockets. Posterior margin of each tergum I–X with regular triangular pointed denticles (
Fig. 138
). Sterna I–V with posterior margin entirely smooth, sternum VI with few small denticles, sterna VII–IX with pointed denticles on posterior margin. Paraprocts with shorter and longer marginal denticles (
Fig. 129
). Tergalius I absent. Tergalii II–VII oval, with anal margin more convex than costal margin; margin entirely bordered by well-developed rib, serrate; surface without denticles and scales; tracheae colored with light brownish (Fig. 116, 117). Cerci somewhat shorter than body length, paracercus somewhat shorter than cerci (Figs 113, 115). Posterior margins of segments of cerci and paracercus with equal triangular denticles, subequal to denticles on posterior margin of abdominal terga.
Subimago
.
CUTICULAR COLORATION. Light ocher and brownish. Pronotum light brownish. Mesonotum light brownish with medioparapsidal suture contrastingly light, other sutures slightly darkened (
Fig. 119
). Thoracic pleura ocher, with some sclerites light brownish, lateropostnotal crest and postsubalar sclerite without contrasting coloration (
Fig. 120
). Abdomen unicolor light brownish, legs and cerci lighter ocher.
TEXTURE (see
Table 2
). On fore leg of male 1st–4th tarsomeres covered by blunt microlepides, 5th tarsomere covered by pointed microlepides. On fore leg of female 1st tarsomere covered mainly by microtrichia (as tibia), 2ndt–4th tarsomeres covered by blunt microlepides, 5th tarsomere covered by pointed microlepides. On middle and hind legs of male and female proximal part of 1st+2nd tarsomere (corresponding to primary 1st tarsomere) covered by microtrichia, distal part of 1st+2nd tarsomere (corresponding to primary 2nd tarsomere), 3rd and 4th tasomeres covered by blunt microlepides, 5th tarsomere covered by pointed microlepides (
Fig. 134
).
Imago, male
(
Fig. 121
). Head ocher with brown. Turbinate eyes widened apically, with facetted surface ocher, stem light ocher. Thorax light brown with ocher areas. Wing membrane colorless, veins ocher. Pterostigma with several oblique complete and incomplete veins (
Kopelke 1980a:
Fig. 28
). Hind wing absent. Legs unicolor ocher. Tarsus of middle and hind leg with 3 apical spines, on segments 1st+2nd, 3rd and 4th (the same in subimago—Fig. 134) (
Table 2
). All abdominal terga ocher-brownish with lighter longitudinal median stripe and lighter paired medioanterior and medioposterior sigilla (the same in subimago—Fig. 114). Abdominal sterna lighter than terga, ocher. Cerci unicolor ocher.
Male genital structure and development.
Imaginal genitals as in
Figs 1
,
131
. Sterno-styligeral muscle completely absent. Each gonovectis with apex free end straight, not hooked and not bordering distal margin of membranous sack. Penial bridge forms prominent median projection rounded apically. Apical margin of each unistyliger medially with roundish projection directed medially. Gonostylus with 1st segment smoothly narrowed toward apex, with inner margin convex; 2nd segment slightly widened toward apex; 3rd segment short.
Protogonostyli of male larva represent very shallow convexities of posterior margin of abdominal sternum IX. In mature larva ready to molt to subimago, subimaginal gonostyli are packed under larval cuticle in «
Labiobaetis
- pose»: second segments directed medially and bent (
Fig. 130
).
Imago, female
(
Fig. 118
). Head and thorax ocher with light brownish, lighter than in male. Wings as in male. Tarsus of fore leg with 2 apical spines, on segments 2nd and 3rd (i.e., without apical spine on penultimate tarsomere); middle and hind legs as in male (i.e., with apical spine on penultimate tarsomere). All abdominal terga ocher-brownish with lighter longitudinal median stripe; terga II–VI with posterior margins diffusively darkened with brown, except light longitudinal median stripe.
Eggs
(
Figs 139–141
). About 0.1 mm length. Broad-oval or nearly spherical, with fine punctuation (
Kopelke 1980b:
Fig. 20
). One pole with round, shallowly convex cap; several long and thin processes arise from periphery of this cup; each process bears on its end spherical or ellipsoid adhesive knob (
Kopelke 1980b:
Figs 19
,
21
). Unlike coiled knob-terminated threads of eggs of some other mayflies, the knob-terminated processes of
L. tenuicrinitus
are always straight or arched, resilient, unable to coil up.
Dimension.
Fore wing length of male and female about
5 mm
.
Discussion.
The description given above, is based on the specimens collected in the west of
Uganda
, close to the boundary with the Democratic Republic of
Congo
.
The species under the name
Pseudocloeon tenuicrinitum
was described from
River
Kalengo, located in the neighboring region of the D. R.
Congo
. The original descriptions were based on male and female imagoes and eggs (
Kopelke 1980a
,
1980b
). Characters reported in these papers allow to determine this species without doubt: eggs have unusual structure (
Kopelke 1980b:
Figs 19–21
); genitals of male imago are described and figured in detail, including pointed gonovectes, rounded median projection, characteristic shape of medio-apical projection of unistyligers and characteristic shape of gonostyli (
Kopelke 1980a
:
Figs 27
a, b); pointed apical spine on penultimate tarsomere is figured (
Kopelke 1980a:
Fig 29
,
8
th position
). Judging by these characters, as well as by coloration, our imagoes reared from larvae in Uganda, undoubtedly belong to this species.
Gillies (1994)
described the species under the name
Baetis spatulatus
based on imagoes reared from larvae in
Tanzania
. He did not describe its eggs, and did not compare imagoes of
spatulatus
[
Baetis
] with
tenuicrinitum
[
Pseudocloeon
], but only noted that "The adult of
B. spatulatus
is poorly differentiated from several other species in which the hind wing is lost". Examination of the reared material from
Uganda
allows to conclude that
spatulatus
[
Baetis
] is conspecific with
tenuicrinitum
[
Pseudocloeon
].
Distribution.
Kongo
,
Tanzania
,
Uganda
.