Description of a new African genus and a new tribe of Speleketorinae (Psocodea: `Psocoptera': Prionoglarididae)

Abstract

Prionoglaridids are probably the most basal family of extant psocids and may be considered as living fossils. The genus Afrotrogla gen. n. is described for three new species from southern Africa, two of them only known from caves: A. oryx sp. n. (South Africa, in cave, type species), A. maraisi sp. n. (Namibia) and A. fabella sp. n. (Namibia, in cave). The male of the second African genus of the subfamily, Sensitibilla Lienhard, is described for the first time and two new species of Sensitibilla are described, one of them only known from a cave: S. brandbergensis sp. n. (Namibia) and S. roessingensis sp. n. (Namibia, in cave). Some structures of the type species S. strinatii Lienhard are also illustrated. A comparison of these two genera with the third known genus of the subfamily, the North American Speleketor Gurney, shows that the African genera are characterized by some striking synapomorphies in male and female genitalia. Thus a subdivision of the subfamily Speleketorinae in two tribes is proposed: Speleketorini for Speleketor and Sensitibillini trib. n. for Sensitibilla and Afrotrogla. Among other features, Sensitibillini are characterized by the presence of a trichobothrium on the hindtarsus. Tarsal trichobothria are not known elsewhere in insects. Male and female terminalia of Speleketor irwini Mockford are also illustrated.

Full text

Description of a new African genus and a new tribe of
Speleketorinae (Psocodea: ‘Psocoptera’: Prionoglarididae)
Charles LIENHARD
Muséum d’histoire naturelle, c. p. 6434, CH-1211 Genève 6, Switzerland.
E-mail: charles.lienhard@ville-ge.ch
Description of a new African genus and a new tribe of Speleketorinae
(Psocodea: ‘Psocoptera’: Prionoglarididae). - Prionoglaridids are pro -
bably the most basal family of extant psocids and may be considered as
living fossils. The genus Afrotrogla gen. n. is described for three new
species from southern Africa, two of them only known from caves: A. oryx
sp. n. (South Africa, in cave, type species), A. maraisi sp. n. (Namibia) and
A. fabella sp. n. (Namibia, in cave). The male of the second African genus
of the subfamily, Sensitibilla Lienhard, is described for the first time and
two new species of Sensitibilla are described, one of them only known from
a cave: S. brandbergensis sp. n. (Namibia) and S. roessingensis sp. n.
(Namibia, in cave). Some structures of the type species S. strinatii Lienhard
are also illustrated. A comparison of these two genera with the third known
genus of the subfamily, the North American Speleketor Gurney, shows that
the African genera are characterized by some striking synapomorphies in
male and female genitalia. Thus a subdivision of the subfamily
Speleketorinae in two tribes is proposed: Speleketorini for Speleketor and
Sensitibillini trib. n. for Sensitibilla and Afrotrogla. Among other features,
Sensitibillini are characterized by the presence of a trichobothrium on the
hindtarsus. Tarsal trichobothria are not known elsewhere in insects. Male
and female terminalia of Speleketor irwini Mockford are also illustrated.
Keywords: Trogiomorpha - new species - cave fauna - living fossils -
tricho bothria - Namibia - South Africa - North America.
INTRODUCTION
Within the order Psocodea (sensu Yoshizawa & Johnson, 2006) the ‘Psocoptera’
family Prionoglarididae forms one of the most basal clades of the basal suborder
Trogiomorpha and has recently been classified in an infraorder of its own, the
Prionoglaridetae (see Yoshizawa et al., 2006). The family has been subdivided into two
subfamilies by Lienhard (2004), Prionoglaridinae and Speleketorinae. Each of the sub-
families has been shown to be monophyletic by both morphological and molecular
analyses (Lienhard, 2004; Yoshizawa et al., 2006). The nominate subfamily contains
the Palaearctic genus Prionoglaris Enderlein (3 species, see Lienhard & Smithers,
REVUE SUISSE DE ZOOLOGIE 114 (3): 441-469; septembre 2007
Manuscript accepted 07.03.2007

2002) and the Oriental genus Siamoglaris Lienhard (monotypic, see Lienhard, 2004);
the subfamily Speleketorinae contains the Nearctic genus Speleketor Gurney (3
species, see Lienhard & Smithers, 2002) and the Aethiopian genus Sensitibilla
Lienhard (up to now monotypic, see Lienhard, 2000). Most of the few known priono -
glaridid species live in caves or similar habitats and are considered as very rare.
The family is characterized among extant members of the Psocoptera by its
unique and absolutely diagnostic forewing venation, in particular by the well- de -
veloped and strongly arched basal section of Sc, joining R1 near base of pterostigma,
and by the presence of a long cross-vein between base of pterostigma and distal section
of Rs. However, very similar wing venations have been observed in several of the
oldest known fossil Trogiomorpha, recently described from Cretaceous amber and
assigned to different families (see Baz & Ortuño, 2000, 2001; Perrichot et al., 2003;
Azar & Nel, 2004). Therefore the characters of wing morphology have to be consi -
dered as symplesiomorphic in extant Prionoglarididae for which the term “living
fossils” may be appropriate. Thus, Yoshizawa et al. (2006) have tentatively postulated
that they are Pangaean relicts, in view of their extremely disjunct distribution, their
cavernicolous biology and in agreement with the results of the most recent phylo -
genetic and palaeontological analyses of Psocodea.
Contrary to the monophyly of the subfamilies, the monophyly of the family
Prionoglarididae was only weakly supported by the available molecular data
(Yoshizawa et al., 2006) and its morphological definition is only based on the tentative
autapomorphy of the phallosome structure and the possibly autapomorphic simpli fi -
cation or reduction of the lacinia in adults (Mockford, 1984; Lienhard, 2004).
However, the latter may also be interpreted as an adaptive homoplasy related to the
particular biology of these generally cavernicolous psocids.
In this paper five new African species of the subfamily Speleketorinae,
belonging to the genus Sensitibilla and to a new genus, Afrotrogla gen. n., are
described on the basis of material from Namibia and South Africa deposited in the
National Museum of Namibia, Windhoek. This material allows the description of the
formerly unknown male of Sensitibilla and of both sexes of the new genus, enabling
us for the first time to compare also male genital structures between the African and
American members of the subfamily. The African genera have some striking synapo-
morphies in male and female genitalia rendering these structures completely different
from the genitalia of Speleketor. This fundamental difference in genital morphology,
together with some other characters, justifies the establishment of a new tribe,
Sensitibillini trib. n., for the African genera. The remaining genus of the subfamily, the
North American Speleketor, constitutes the nominate tribe Speleketorini.
From this study of new African material the presence of tibial and tarsal tri-
chobothria in these psocids, as described for Sensitibilla strinatii Lienhard (see
Lienhard, 2000), can be confirmed. The first SEM micrographs of such trichobothria,
which are unique in Psocoptera, are presented together with a brief discussion on leg
trichobothria in insects.
The following abbreviations are used in the descriptions: BL = body length (in
alcohol); F = hindfemur (length); f1, f2, etc. = antennal flagellomeres (length); FW =
forewing (length); HW = hindwing (length); IO/D= shortest distance between
C. LIENHARD
442

compound eyes divided by anteroposterior diameter of compound eye in dorsal view
of head; P1-P4 = articles of maxillary palp; T = hindtibia (length); t1, t2, t3 = tarso -
meres of hindtarsus (length, measured from condyle to condyle). Abbreviations of
wing veins and cells are used according to Yoshizawa (2005). – The material examined
has been deposited in the following institutions: MHNG Muséum d’histoire naturelle,
Geneva, Switzerland; NMN National Museum of Namibia, Windhoek.
TAXONOMIC TREATMENT
KEY TO THE TRIBES AND GENERA OF SPELEKETORINAE AND TO THE SPECIES OF
SENSITIBILLINI
Note. A key to the subfamilies of Prionoglarididae (Prionoglaridinae and
Speleketorinae) and to the genera of Prionoglaridinae (Prionoglaris Enderlein and
Siamoglaris Lienhard) has been given by Lienhard (2004). For figures of Speleketor
spp. see also Gurney (1943), Mockford (1984, 1993) and Lienhard (2000); for figures
of Sensitibilla strinatii see also Lienhard (2000).
1Hindwing with vein Rs 2-branched (Fig. 3i). Forefemur with a longitu-
dinal row of articulated spines on anterior face. Some long and fine tri-
chobothria present on femora and on some trochanters, no trichobothria
on other segments of legs. P4 with 7 thin-walled conical sensilla, two of
them situated in basal half (Fig. 3c). Female genitalia (Fig. 1c): Ovi -
positor consisting of a pair of very broad and simple external valvulae,
peripherically setose, laterally articulated to clunium but not fused to
subgenital plate ventrobasally (a reduced triangular and bare dorsal
valvula is also present, completely covered by the external valvula);
spermathecal duct short and relatively wide. Male genitalia (Fig. 2cd):
Phallosome with a posterolateral pair of pore-bearing processes, scle-
rites of phallosome anteriorly closed, posteriorly open (Speleketorini)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Speleketor Gurney, 1943
Three Americal species known (keyed by Mockford, 1993). Type species:
S. flocki Gurney.
1’ Hindwing with vein Rs simple (Fig. 4b). Forefemur with only a longitu-
dinal row of normal setae on anterior face. Some long and fine tri-
chobothria (see Pl. 1) present on tibiae and hindtarsus, no trichobothria
on other segments of legs. P4 with 2-5 thin-walled conical sensilla situ-
ated in apical half. Female genitalia (Figs 4g, 8c): Ovipositor consisting
only of a pair of external valvulae, laterally articulated to clunium and
ventrobasally fused to subgenital plate, each valvula bearing a distal
process with a claw-like articulated spine at its tip; spermathecal duct
long and thin. Male genitalia (Figs 5c, 9df): Phallosome lacking pore-
bearing processes, sclerites of phallosome anteriorly open, posteriorly
convergent or forming a closed aedeagal arch . . . . . . . (Sensitibillini trib. n.) 2
2(1’) Hindwing with vein M 2-branched (Fig. 4b). P4 with 5 thin-walled
conical sensilla (Fig. 3e). Female genitalia (Fig. 4g): Posterior part of
subgenital plate sclerotized and clearly visible medially between ovi -
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NEW AFRICAN SPELEKETORINAE

positor valvulae; spermapore situated near posterior end of a mem -
branous sac bearing a complex scaffolding of sclerotized struts. Male
genitalia (Fig. 5c): Phallosome with a narrow sclerite forming a simple
aedeagal arch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (Afrotrogla gen. n.) 3
2’ Hindwing with vein M simple (Fig. 9b). P4 with 2 thin-walled conical
sensilla (Fig. 3g). Female genitalia (Fig. 8c): Posterior part of sub genital
plate membranous and almost completely covered ventrally by the
ovipositor valvulae; spermapore situated at the distal end of a small cap-
like structure bearing a simple needle-like sclerite (the spermathecal
duct running through the eye of the needle). Male genitalia (Fig. 9df):
Phallosome with a pair of relatively broad sclerites, each bearing a
narrow internal branch, these branches posteriorly convergent or fused
to form a median aedeagal arch . . . . . . . . . . . . (Sensitibilla Lienhard, 2000) 5
3(2) Head with striking dark brown colour pattern (Fig. 5a) . . Afrotrogla oryx sp. n.
3’ Head pattern different or head uniformly medium brown . . . . . . . . . . . . . . . . 4
4(3’) Head pattern as in Fig. 6a. Relatively small species: Body length and
forewing length about 3 mm, hindtibia length 1.2 mm. Compound eyes
relatively large: IO/D 2.6 . . . . . . . . . . . . . . . . . . . . . . Afrotrogla maraisi sp. n.
4’ Head uniformly medium brown. Large species: Body length and
forewing length about 4 mm, hindtibia length 2.2 mm. Compound eyes
relatively small: IO/D 3.4 . . . . . . . . . . . . . . . . . . . . . . Afrotrogla fabella sp. n.
5(2’) Male (unknown in S. strinatii) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5’ Female (unknown in S. roessingensis) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6(5) Small species: Hindtibia length 1.0 mm. Abdomen white, lacking
hypodermal pigmentation. Phallosome as in Fig. 9d
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensitibilla brandbergensis sp. n.
6’ Slightly larger species: Hindtibia length 1.3 mm. Abdomen with some
brown hypodermal pigmentation. Phallosome as in Fig. 9f
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensitibilla roessingensis sp. n.
7(5’) Small species: Hindtibia length 1.0 mm. Abdomen white, lacking hypo-
dermal pigmentation. Female genitalia (Fig. 8ac): Subgenital plate
entirely membranous (except for sclerotized rims in zone of fusion with
ovipositor valvulae), its posterior part triangular, with bluntly pointed
apex; ovipositor valvula laterally articulated near anteroventral angle of
clunium, anterior margin of clunium prolonged into a broad ventral fold
on the valvula; distal process of ovipositor valvula with only one spine-
like seta in apical half apart from the spine on its tip; sclerotized plate on
spermathecal wall large (greatest width about 500 μm)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sensitibilla brandbergensis sp. n.
7’ Larger species: Hindtibia length 1.5 mm. Abdomen with some brown
hypodermal pigmentation. Female genitalia: Anterior part of subgenital
plate with a bilaterally symmetrical sclerified area connected to
anteroventral angle of clunium; membranous posterior lobe of sub -
genital plate apically rounded; ovipositor valvula laterally articulated at
posteroventral angle of clunium, anterior margin of clunium not
C. LIENHARD
444

prolonged onto the valvula; distal process of ovipositor valvula with
3-4 spine-like setae in apical half apart from the spine on its tip;
sclerotized plate on spermathecal wall much smaller (greatest width
about 250 μm) . . . . . . . . . . . . . . . . . . . . . Sensitibilla strinatii Lienhard, 2000
SENSITIBILLINI trib. n.
DIAGNOSIS: Belonging to the subfamily Speleketorinae of the Prionoglarididae
as defined by Lienhard (2004). Habitus similar to Speleketor (Fig. 1a). Hindwing (Figs
4b, 9b) with Rs simple and M 2-branched or simple. Forefemur lacking a longitudinal
row of short articulated spines on anterior face. Pretarsal claws with distinct preapical
tooth (Fig. 4d). Trichobothrial pattern on legs (see Lienhard, 2000: figs 17-21):
Foretibia and midtibia with two external trichobothria in nymphs and adults; hindtibia
with two such trichobothria in nymphs, usually the proximal one not differentiated in
adults; hindtarsus with one trichobothrium on second article in nymphs and adults
(Pl. 1); coxa, trochanter and femur of all legs and tarsus of foreleg and midleg lacking
trichobothria in nymphs and adults. P2 with a subbasal sensory spur, P4 with 2-5 thin-
walled conical sensilla in apical half (Fig. 3e). Tines of lacinial tip well-developed in
nymphs (Fig. 5f), strongly reduced in adults (Fig. 4ef). Forewing with a row of acu -
minate denticles on distal section of vein Sc delimiting the pterostigma basally (see
Lienhard, 2000: Fig. 2). Paraprocts in both sexes dorsally with a group of several
relatively short trichobothria inserted in simple pit-like sockets, and with one normal
seta between them (Fig. 5d). Female genitalia (Fig. 4g, 8c): Ovipositor consisting only
of a pair of external valvulae, laterally articulated to clunium and ventrobasally fused
to subgenital plate, each valvula bearing a distal process with a claw-like articulated
spine at its tip; spermathecal duct long and thin. Male genitalia (Figs 7bc, 9df):
Phallosome lacking pore-bearing processes, sclerites of phallosome anteriorly open,
posteriorly convergent or forming a closed aedeagal arch.
TYPE GENUS: Sensitibilla Lienhard.
ADDITIONAL GENUS:Afrotrogla gen. n.
DISCUSSION: The particular trichobothrial pattern on legs, especially the
presence of a tarsal trichobothrium, is probably an autapomorpy of this tribe (see also
General Discussion, below). An even more impressive autapomorphy is the very par-
ticular structure of external ovipositor valvulae and subgenital plate, basally fused to
form a functional unit, which is unknown elsewhere in Psocoptera. Two additional
autapomorphies of this tribe are the presence of a row of acuminate denticles on the
distal section of Sc on the forewing (no such denticles in Speleketor and the
Prionoglaridinae) and the reduction of the Rs branching in the hindwing (Rs bifurcate
in all other Prionoglarididae, see Fig. 3hi), while M initially remains 2-branched in the
hindwing (simple in Sensitibilla), with M1 and M2 originating separately from Rs-M
fusion, as in Speleketor (Fig. 3i), or from M stem and Rs-M fusion, respectively (M bi-
furcate in Prionoglaridinae, Fig. 3h). The absence of the pair of posterolateral pore-
bearing processes of the phallosome can also be interpreted as an autapomorphy of this
tribe. Such processes are present in Speleketor and the Prionoglaridinae (see Lienhard,
2004). They have been considered as homologous with the pore-bearing external para-
445
NEW AFRICAN SPELEKETORINAE

meres of other Psocoptera by Mockford (1984). If this homology is correct, then these
processes belong to the groundplan of the trogiomorphan phallosome and their
presence in Speleketor and the Prionoglaridinae is a symplesiomorphy.
Afrotrogla gen. n.
DIAGNOSIS: Habitus very similar to Sensitibilla and Speleketor (see Fig. 1a and
Gurney, 1943: fig. 3). General morphology of female and nymph as described for
Sensitibilla (see Lienhard, 2000), with the following differences. P4 with 5 thin-walled
conical sensilla in apical half (Fig. 3def). Hindwing (Fig. 4b) with Rs simple and M 2-
branched (M1 and M2 originating separately from Rs-M fusion or from M stem and
Rs-M fusion, respectively). Third article of hindtarsus in females preapically with a
dorsal pair of long and slender curved hairs (Fig. 4d); the corresponding hairs much
shorter in males and on foretarsus and midtarsus of both sexes (cf. Fig. 5e). Females
with some long backwards-directed sternal setae near midline at about basal one third
of abdomen (Fig. 4c, 6g); these setae absent in males. Ventral half of female paraproct
with numerous short setae (Fig. 6b), lacking the circular field of long dense pilosity
present in Sensitibilla (cf. Lienhard, 2000: Fig. 29). Female genitalia (Fig. 4g):
Posterior part of subgenital plate sclerotized and clearly visible medially between
ovipositor valvulae; spermapore situated near posterior end of a membranous sac
bearing a complex scaffolding of sclerotized struts; spermathecal duct long and thin;
spermatheca thin-walled, its wall with small pores and, near origin of duct, with some
sclerotized wrinkles (Figs 4g, 6c). General morphology of male as in female (for
exceptions, see above). Male terminalia: Epiproct and paraproct simple (Fig. 7d), or
epiproct with prominent ventral lobe (Fig. 5d); hyandrium simple (Fig. 5b); phallo-
some with a narrow sclerite forming a simple aedeagal arch (Fig. 7bc).
TYPE SPECIES:Afrotrogla oryx sp. n.
ETYMOLOGY: The name is feminine in gender and refers to the African distri -
bution of the genus and to the cave dwelling habits of its type species (from Greek
“trogle” = hole, cave).
DISCUSSION: See General Discussion, below.
Afrotrogla oryx sp. n. Figs 4, 5
TYPE MATERIAL: NMN, holotype 乆(4 microscopical slides), South Africa, Richtersveld,
Wondergat (in cave), SE 2816 Bd, 24.IX.1994, leg. E. Marais. – NMN, paratypes: 1么allotype
(1 microscopical slide, rest in alcohol) and 1 nymph (2 microscopical slides), same data as for
holotype.
DESCRIPTION: Male and female: See diagnosis of tribe and genus, with the
following additions. Head yellowish, with striking cuticular colour pattern (Fig. 5a)
consisting of a dark brown postclypeus and a broad, dark brown transversal band
running from gena over frons and parts of vertex; labrum medium brown; compound
eyes black; antenna brown. Prothorax yellowish, except for dark brown pronotum.
Forelegs entirely yellowish to light brown, midlegs and hindlegs ditto, but with dark
brown coxae. Pterothorax entirely dark brown. Wings transparent (pterostigma very
slightly opaque), veins brown. Abdomen dorsally and laterally with much dark brown
C. LIENHARD
446

447
NEW AFRICAN SPELEKETORINAE
FIG. 1
Speleketor irwini Mockford, female from Palm Springs, California: (a) Habitus, lateral view, left
appendages not figured, scale 1 mm. (b) Epiproct and right paraproct. (c) Genitalia, ventral view:
Ovipositor valvulae with their articulation to clunium, subgenital plate, spermapore, sperma -
thecal duct and beginning of spermathecal sac (dorsal valvulae and spermatheca represented by
interrupted lines).

C. LIENHARD
448
FIG. 2
Speleketor irwini Mockford, male from Palm Springs, California: (a) Hypandrium. (b) Epiproct
and right paraproct. (c) Phallosome, lateral view, de = ductus ejaculatorius. (d) Ditto, dorsal
view.

449
NEW AFRICAN SPELEKETORINAE
FIG. 3
Thin-walled conical sensilla of P4, other pilosity not figured (a-g): (a) Prionoglaris stygia
Enderlein, female from type locality. (b) Siamoglaris zebrina Lienhard, male holotype. (c)
Speleketor flocki Gurney, female paratype. (d) Afrotrogla maraisi sp. n., female holotype, apical
half of both P4. (e) Ditto, left maxillary palp, spine-like sensillum of P2 also figured. (f)
Afrotrogla fabella sp. n., male holotype, apical half of both P4. (g) Sensitibilla roessingensis
sp. n., male holotype, with detail of proximal sensillum. – Hindwing (h-i): (h) Prionoglaris
stygia Enderlein, female from type locality. (i) Speleketor flocki Gurney, female paratype.

hypodermal pigment, pattern not clearly defined (examined after 11 years in alcohol),
but essentially consisting of two broad transversal bands; terminalia brown.
Head capsule with a slightly concave semicircular groove between lateral
ocelli, passing by the bifurcation point of the epicranial suture; frontal suture weakly
developed; ocelli arranged in a flat triangle (Fig. 5a); compound eyes small, approxi-
mately of same size in both sexes (IO/D: 乆2.8, 么2.9). Antenna thin and apparently
very long (extrapolated from lengths of basal flagellomeres, see measurements; all
antennae damaged in the material available), the basal three flagellomeres together
about equal to body length (the very similar values for the antennae of the holotype,
both broken after f4, show that probably no asymmetrical regenerative length growth
occurred, see remark in Lienhard, 2004: 870). Mouthparts generally as described for
Sensitibilla strinatii by Lienhard (2000). All maxillary palps broken in the material
available. Lacinia with reduced apical tines, outer part of its tip usually slightly
indented (Fig. 4ef). Venation of forewing typical for the family (Fig. 4a). Hindwing:
R1 always present; M1 originating from Rs-M fusion (Fig. 4b) or from M stem,
slightly basally to Rs-M fusion; M2 originating from Rs-M fusion. Spine-like setae on
tibiae and tarsi with more or less rounded tips. Pearman-organ of hindcoxa not
differen tiated, only a mirror-like membranous area present basally on inner side of
hindcoxa, both midcoxae with a distinctly prominent hyaline tubercle on inner side.
Third article of hindtarsus of female subapically with a pair of slender dorsal hairs,
slightly curved ventrally and longer than length of claw (Fig. 4d). These specialized
hairs not differentiated in male, there the corresponding setae shorter than the claw
(cf. Fig. 5e). Proximal trichobothrium of hindtibia usually not differentiated in adults,
corresponding to the general pattern of leg trichobothria in Sensitibillini, but this
trichobothrium on one hindtibia of the allotype male also well-developed. Female with
two tufts of long backwards-directed sternal setae medially at about basal one third of
abdomen, very close to midline and practically fused to one single tuft (Fig. 4c). No
such sternal setae in male.
Female terminalia (Fig. 4g): Epiproct and paraproct simple (cf. Fig. 6b).
Ovipositor valvula with a long and almost straight distal process bearing a short claw-
like apical spine and numerous short stout hairs, most of them situated on dorsal side
of process; basal part of valvula with a transversal row of subapical dorsal setae and
one long ventral seta on each side of base of distal process; basal part of valvula ex-
ternally articulated at posteroventral angle of clunium, its internal margin curved and
well-sclerotized, running parallel to hind margin of subgenital plate, posterointernal
angles of valvulae almost touching each other medially. Posterior part of subgenital
plate well-sclerotized but otherwise simple and bare, its anterior margin concave and
anterolaterally prolonged into a long sclerotized rim fused to inner base of the
corresponding ovipositor valvula; anterior part of subgenital plate a weakly sclero-
tized, almost circular plate bearing some sparse setae; transition zone between posteri-
or and anterior parts of subgenital plate membranous; sclerotized anterior margin of
posterior part with a group of about a dozen small hairs situated on the slightly hollow
median zone of this margin (thus their insertion points not visible in ventral view), no
porus present between these hairs. Spermapore situated near posterior end of an elon-
gate membranous sac (interrupted line in Fig. 4g), with a small circular sclerite, in situ
C. LIENHARD
450

clearly visible through membranous zone just anteriorly to concave margin of posterior
part of subgenital plate. Spermathecal duct long and thin, somewhat spirally curled, its
posterior half situated in the above mentioned membranous sac, the latter equipped
451
NEW AFRICAN SPELEKETORINAE
FIG. 4
Afrotrogla oryx sp. n., female holotype: (a) Forewing, scale 1 mm. (b) Hindwing, same scale.
(c) Tuft of long backwards-directed sternal setae medially at about basal one third of abdomen.
(d) Apex of third article of hindtarsus, with dorsal pair of long curved hairs, only one claw
illustrated. (e) Lacinial tip, left. (f) Ditto, right. (g) Genitalia, ventral view, scale 0.2 mm:
Ovipositor valvulae with ventrolateral parts of clunium, subgenital plate and, observed in situ
through ventral membranes, spermapore and spermathecal duct with accessory structures and
sclerotized wrinkles on spermathecal wall.

with a complex scaffolding of sclerotized struts. The median paired struts situated
ventrally on the sac, originating as a simple rod at the spermapore and, towards their
anterior ends, successively bifurcating into a circular strut forming the anterior border
of the sac, and into a pair of long lateral struts. The latter backwards-directed, slightly
curved and with free posterior ends (probably movable, cf. Figs 4g and 6d). Sperma -
thecal wall, near origin of duct, with some bilaterally symmetrical, sclerotized
wrinkles. One spermatophore (sperm packet) clearly visible in the spermatheca of the
holotype, simple, slightly pear shaped, but much more elongate than the sperma -
tophores of Sensitibilla strinatii illustrated by Lienhard (2000: fig. 25).
Male terminalia: Epiproct simple, paraproct with a ventrally prominent pos -
terior lobe (Fig. 5d). Hypandrium (Fig. 5b) with a characteristic sclerotized pattern.
Phallosome developed as a membranous sac (cf. Fig. 7c), dorsally with a relatively
long but simple, arched and posteriorly truncate aedeagal sclerite (Fig. 5c).
Nymph: One nymph (probably male) examined, late instar (see Discussion,
below). See diagnosis of tribe and genus, with the following additions. Body colour
entirely yellowish white (adult head pattern not yet recognizable), except for dark
pigment in compound eyes and ocellar dots, and two large brown transversal bands on
abdominal tergites. General morphology as desribed for the nymph of Sensitibilla
strinatii by Lienhard (2000). Both maxillary palps broken. Lacinia with three well-
developed apical tines (Fig. 5f) (one lacinia damaged). Terminal article of hindtarsus
subapically without a pair of long curved hairs (Fig. 5e) (see Discussion, below).
MEASUREMENTS: Female holotype. BL = 3.1 mm; FW = 4.0 mm; HW = 1.9 mm;
F = 1030 μm; T = 1750 μm; t1= 630 μm; t2 = 140 μm; t3 = 175 μm; flagellomeres
(left/right): f1 = 900/870 μm; f2 = 1040/960 μm; f3 = 1220/1200 μm. – Male allotype.
BL = 3.6 mm; FW = 3.7 mm; HW = 1.8 mm; F = 1020 μm; T = 1750 μm; t1= 610 μm;
t2 = 140 μm; t3 = 165 μm.
ETYMOLOGY: The specific epithet is a noun in apposition alluding to the South
African Oryx antelope (Oryx gazella gazella) which has a somewhat similar dark
brown colour pattern on its head.
DISCUSSION: The type locality of Afrotrogla oryx, the Wondergat cave, is located
in the arid northwestern corner of South Africa, north of Springbok and close to the
Namibian border, quite far away from the type localities of the other known species of
Sensitibillini in western, central or northeastern Namibia. This is the only species of
the genus of which both sexes are known. Males of A. oryx and A. fabella are very
similar in their phallosome morphology, but these species can easily be distinguished
by paraproct shape, body size and especially by the colour pattern of the head. The very
complex morphology of female genitalia allows a more detailed comparison of A. oryx
with A. maraisi, the latter only known from the female holotype collected in central
Namibia (Windhoek). The striking differences in the structure of the subgenital plate
indicate that these species are only distantly related (see Discussion of A. maraisi).
The absence of the dorsal pair of long curved preapical hairs in the male,
present on female hindtarsus, corresponds to the situation observed in the nymph.
Therefore the latter is believed to be a male nymph, because it seems likely that these
specialized hairs are present in female nymphs, rather than being generally absent in
nymphs and restricted to adult females.
C. LIENHARD
452

Afrotrogla maraisi sp. n. Figs 3de, 6
TYPE MATERIAL: NMN, holotype 乆(3 microscopical slides, rest in alcohol), Namibia,
Windhoek, 10.X.1995, leg. E. Marais.
DESCRIPTION: Female (male unknown): See diagnosis of tribe and genus, with
the following additions. Head generally light brown, the following areas with reddish
453
NEW AFRICAN SPELEKETORINAE
FIG. 5
Afrotrogla oryx sp. n., male allotype (a-d): (a) Head, frontal view. (b) Hypandrium, with left
attachment to clunium. (c) Sclerite of phallosome, scale 0.2 mm. (d) Epiproct and left paraproct.
– Afrotrogla oryx sp. n., nymph (e-f): (e) Hindtarsus, t2 with trichobothrium and apical part of
t1, only one claw illustrated. (f) Lacinial tip.

brown hypodermal pigment (Fig. 6a): Gena and base of mandible; a triangular arrow-
like patch dorsally between lateral ocellus and compound eye pointing towards anterior
end of vertical suture; a small longitudinal patch near anterior end of vertical suture.
Compound eyes black, antenna and maxillary palp light brown. Prothorax light brown,
pterothorax medium brown, legs yellowish to light brown. Wings transparent (ptero -
stigma very slightly opaque), veins medium brown. Abdomen yellowish, with much
dark brown hypodermal pigment, pattern not clearly defined (examined after 10 years
in alcohol), but apparently consisting of some segmental patches and transversal bands;
terminalia light to medium brown.
Shape of head capsule (Fig. 6a) similar to that of A. oryx, frontal suture reduced,
ocelli arranged in a flat triangle (Fig. 6a), compound eyes small (IO/D 2.6). Antenna
thin and distinctly longer than forewing. One antenna of the holotype apparently
complete (i. e. last flagellomere slightly tapering to a regularly rounded tip, bearing a
conspicuous terminal sensillum), 11-segmented, the other one broken after f4 (the
considerably higher values for lengths of f1 to f3 for the latter may indicate some
regenerative length growth, see remark in Lienhard, 2004: 870). Mouthparts generally
as described for Sensitibilla strinatii by Lienhard (2000). Maxillary palp long and
slender, P4 with five thin-walled conical sensilla in apical half, their arrangement
somewhat variable (Fig. 3de). Lacinia and wing venation very similar to that of A.
oryx. Hindwing: R1 present, M1 and M2 originating separately from Rs-M fusion.
Spine-like setae on tibiae and tarsi with more or less rounded tips. Pearman-organ of
hindcoxa not differentiated, only a mirror-like membranous area present basally on
inner side of hindcoxa, both midcoxae with a distinctly prominent hyaline tubercle on
inner side. Trichobothrial pattern on legs typical for Sensitibillini. The dorsal pair of
long curved hairs subapically on third article of hindtarsus well-differentiated, longer
than claw. Two well-separated tufts of long backwards-directed sternal setae present
near midline at about basal one third of abdomen (Fig. 6g).
Female terminalia: Epiproct and paraproct simple (Fig. 6b). Ovipositor valvula
(Fig. 6e) with a long, relatively broad and slightly curved distal process bearing a short
claw-like apical spine and numerous spine-like setae, most of them situated on dorsal
side of the process and three on its external margin; basal part of valvula with a trans-
versal row of subapical dorsal setae and one long ventral seta on each side of base of
distal process; basal part of valvula externally articulated at posteroventral angle of
clunium, its internal margin only slightly curved and not sclerotized in apical part,
running parallel to lateral hindmargin of subgenital plate, but the two valvulae not
touching each other medially. Posterior part of subgenital plate (Fig. 6e) well-sclero-
tized and bearing a few short hairs, laterobasally fused to inner base of valvulae but not
prolonged into a long sclerotized rim; anterior part of subgenital plate membranous
except for a narrow sclerotized longitudinal area just anteriorly to the middle of the
convex anterior margin of its posterior part. This margin laterally prolonged into a pair
of short curved stylets, ventrally prominent and backwards-directed, the right stylet
bearing a short fine hair on its rounded tip, the left one bare. Sclerotized part of sub-
genital plate perforated by a conspicuous porus in the middle of its anterior margin,
between the bulged bases of the stylets; this porus opening to a sclerotized, digitiform,
backwards-directed invagination of the subgenital plate (interrupted line in Fig. 6f);
C. LIENHARD
454

455
NEW AFRICAN SPELEKETORINAE
FIG. 6
Afrotrogla maraisi sp. n., female holotype: (a) Head, frontal view. (b) Epiproct and right para-
proct. (c) Origin of spermathecal duct and sclerotized wrinkle on spermathecal wall. (d)
Spermapore and posterior part of spermathecal duct, with accessory structures, ventral view,
scale 0.2 mm. (e) Subgenital plate, ovipositor valvulae and ventrolateral parts of clunium, ventral
view, same scale as Fig. 6d. (f) Detail of anteromedian porus on subgenital plate, compare with
Fig. 6e. (g) Pair of tufts of long backwards-directed sternal setae at about basal one third of
abdomen, middle of sternite shown by an interrupted line.

porus surrounded by heavy sclerotization and laterally flanked by some short stout
setae (Fig. 6f), some very fine hyaline hairs (length 3-10 μm) also visible inside the
lumen of the porus (only observable at high magnification). Spermapore with a longi-
tudinally oval annular sclerite (Fig. 6d), in situ situated just dorsally of the digitiform
inva gination of the subgenital plate, near the posterior end of a rounded membranous
sac; spermathecal duct of about the same relative length as in A. oryx (see Fig. 4g),
somewhat spirally curled, its posterior part situated in the above mentioned membra-
nous sac, the latter equipped with a complex scaffolding of sclerotized struts showing
the same elements as in A. oryx (cf. Figs 6d and 4g). Median paired ventral struts
bifurcate posteriorly and not in contact with spermapore sclerite, circular strut
(interrupted line in Fig. 6d) dorsomedially prolonged by a backwards directed process
(NB. Only a small rudiment of such a process visible in A. oryx, see Fig. 4g), lateral
struts straight, only slightly backwards-directed, probably movable. Spermathecal
wall, near origin of duct, with a slightly undulated sclerotized wrinkle (Fig. 6c).
Several spermatophores (sperm packets) visible inside the spermatheca of the holo-
type, pear-shaped, very similar to the spermatophores of Sensitibilla strinatii illus trated
by Lienhard (2000: fig. 25).
MEASUREMENTS: Female holotype. BL = 2.9 mm; FW = 3.0 mm; HW = 1.6 mm;
F = 730 μm; T = 1230 μm; t1= 430 μm; t2 = 113 μm; t3 = 145 μm; flagellomeres
(left/right): f1 = 650/740 μm; f2 = 660/800 μm; f3 = 610/750 μm (left antenna
complete, 11-segmented, total length 3.9 mm).
ETYMOLOGY: The species is dedicated to Dr Eugene Marais, curator of the
entomological collections of the National Museum Namibia and collector of all
currently known specimens of the genus Afrotrogla.
DISCUSSION: The type of Afrotrogla maraisi was collected in Windhoek (central
Namibia), but unfortunately no further information on its habitat is available
(collecting by trap?). The species can easily be distinguished from A. oryx by its head
pattern and by the structure of its genitalia: Different shape and pilosity of ovipositor
valvula; different shapes of spermapore sclerite, of membranous sac around posterior
part of spermathecal duct and of its accessory sclerites; strikingly different structure of
subgenital plate. The presence, on the subgenital plate of A. maraisi, of a basal porus
with a digitiform invagination and a pair of lateral stylets (compared with the simple
subgenital plate of A. oryx), indicates that these species are only distantly related to
each other and could even belong to different genera. At present their generic
separation would of course be premature in view of the poorly known species diver sity
in Sensitibillini. For some remarks on functional morphology see General Discussion
(below).
It seems highly unlikely that A. fabella (male described below, female
unknown) could be the unknown male of A. maraisi. As shown by A. oryx and by
Sensitibilla brandbergensis, there exists no significant sexual dimorphism concerning
general body size, wing length, IO/D index or colouration of head in Sensitibillini.
A. maraisi (female) and A. fabella (male) clearly differ in all these characters (see key,
above).
C. LIENHARD
456

Afrotrogla fabella sp. n. Figs 3f, 7
TYPE MATERIAL: NMN, holotype 么(4 microscopical slides), Namibia, Grootfontein
District, Märchenhöhle (in cave), SE 1917 Cb, 30.VIII.1990, leg. E. Marais.
DESCRIPTION: Male (female unknown): See diagnosis of tribe and genus, with
the following additions. Head uniformly medium brown, no hypodermal pigment
pattern visible (examined after 15 years in alcohol, but abdominal hypodermal pigment
perfectly preserved). Compound eyes black, antenna medium brown, maxillary palp
light brown. Prothorax light brown, pterothorax dorsally dark brown, legs light to
medium brown. Wings transparent (pterostigma very slightly opaque), veins dark
brown. Abdomen yellowish, with characteristic dark brown hypodermal pigment
pattern, especially well-developed dorsally in posterior two thirds of abdomen
(Fig. 7a), terminalia dark brown.
Head capsule slightly concave between lateral ocelli, frontal suture weakly
developed, ocelli arranged in a flat triangle, almost in a line. Compound eyes very
small (IO/D 3.4). Antenna thin and apparently very long (extrapolated from lengths of
basal flagellomeres, see measurements; both antennae damaged in the holotype, one of
them broken after f3, the other after f6), the basal three flagellomeres together about
equal to body length (the very similar values for both antennae of the holotype show
that probably no asymmetrical regenerative length growth occurred, see remark in
Lienhard, 2004: 870). Mouthparts generally as described for Sensitibilla strinatii by
Lienhard (2000). Maxillary palp long and slender, P4 with five thin-walled conical
sensilla in apical half, their arrangement somewhat variable (Fig. 3f). Lacinia and wing
venation very similar to that of A. oryx. Hindwing: R1 present, M1 and M2 originating
separately from Rs-M fusion. Spine-like setae on tibiae and tarsi with more or less
rounded tips. Pearman-organ of hindcoxa not differentiated, only a mirror-like
membranous area present basally on inner side of hindcoxa, both midcoxae with a
distinctly prominent hyaline tubercle on inner side. Trichobothrial pattern on legs
typical for Sensitibillini. Third article of hindtarsus broken on both hindlegs.
Abdominal sternites with transversal rows of few short hairs, no tuft(s) of long sternal
setae present in basal half of abdomen.
Male terminalia: Epiproct simple, paraproct with some sclerotized wrinkles
near group of trichobothria, without prominent posteroventral lobe (Fig. 7d).
Hypandrium simple, similar in shape to that of A. oryx, but entirely brown (cuticular
pigmentation) except for narrow hyaline hindmargin. Phallosome a membranous sac
(Fig. 7c), dorsally with a simple, arched and posteriorly rounded aedeagal sclerite
(Fig. 7b) (NB. The extent of the anterior opening of the aedeagal arch depends on the
degree of squashing of the slide-mounted phallosome).
MEASUREMENTS: Male holotype. BL = 4.2 mm; FW = 4.1 mm; HW = 2.2 mm;
F = 1250 μm; T = 2220 μm; t1 = 850 μm; t2 = 165 μm; t3 broken on both hindlegs;
flagellomeres (left/right): f1 = 1420/1370 μm; f2 = 1530/1410 μm; f3 = 1510/1420 μm.
ETYMOLOGY: The specific epithet refers to the type locality, a cave with the
German name Märchenhöhle (“fairy-tale cave”); it is a noun in apposition (from Latin
“fabella” = Märchen, fairy-tale).
457
NEW AFRICAN SPELEKETORINAE

DISCUSSION: The type locality of Afrotrogla fabella is situated in northeastern
Namibia (19°32’S 17°14’E), far away from Windhoek and the South African
Wondergat cave, from where the two other species of the genus are known. For
distinction from these species see the corresponding discussions and the key (above).
Sensitibilla Lienhard
Lienhard, 2000: 872.
DIAGNOSIS: See Lienhard (2000) with the following additions. Hindwing with
veins Rs and M simple, R1 usually present, rarely absent (see Fig. 9b and Lienhard,
2000: Figs 3, 4). No long curved dorsal hairs subapically on third article of hindtarsus
(Fig. 8b). P4 with 2 thin-walled conical sensilla in apical half (Fig. 3g). Both sexes
without particularly long backwards-directed sternal setae near midline in basal half of
abdomen. Female genitalia (Fig. 8c): Spermapore situated at the posterior end of a
small cap-like structure, bearing a simple needle-like accessory sclerite (the sperma -
thecal duct running through the eye of the needle). General morphology of male as in
female. Male terminalia: Epiproct and paraproct simple (Fig. 9e); hypandrium simple
(Fig. 9c); phallosome lacking pore-bearing processes, with a pair of anteriorly
divergent and relatively broad sclerites, each bearing a narrow posterointernal branch,
these branches convergent (Fig. 9f) or fused to form a median aedeagal arch (Fig. 9d).
TYPE SPECIES:Sensitibilla strinatii Lienhard.
DISCUSSION: See General Discussion, below.
C. LIENHARD
458
FIG. 7
Afrotrogla fabella sp. n., male holotype: (a) Colour pattern of abdomen, dorsal view. (b) Sclerite
of phallosome, scale 0.2 mm. (c) Phallosome, with membranous parts asymmetrically deformed
by slide mounting, dorsal view, de = ductus ejaculatorius. (d) Epiproct and right paraproct.

Sensitibilla strinatii Lienhard Plate 1
Lienhard, 2000: 874.
MATERIAL EXAMINED: MHNG, 乆holotype, 2乆and 7 nymphs paratypes, Namibia,
Arnhem Cave (124 km SE of Windhoek), in cave, 21.X.1999, leg. P. Strinati.
DESCRIPTION: Female (male unknown). See original genus and species descrip-
tion, key (above) and extended generic diagnosis (above).
DISCUSSION: See Discussion of S. brandbergensis and S. roessingensis (below).
Sensitibilla brandbergensis sp. n. Figs 8, 9a-d
TYPE MATERIAL: NMN, holotype 么(2 microscopical slides), Namibia, Brandberg,
Wasserfallfläche, 1980m, 21°13.5’S 14°31.1’E, 10-12.XI.1998, Malaise trap, river bed, leg.
A. H. Kirk-Spriggs. – NMN, paratypes: 1乆(1 microscopical slide, rest in alcohol), Namibia,
Brandberg, Wasserfallfläche, 1960m, 21°10.77’S 14°32.87’E, 7-10.IV.1999, Malaise trap, well-
vegetated valley below waterfall, bushy Karoo-Namib shrubland (NA99-M05), leg. S. van Noort
& S. G. Compton. 1乆(alcohol), Namibia, Brandberg, Messum Valley, 700m, 21°13.29’S
14°30.98’E, 5-17.IV.1999, Malaise trap, bushy Karoo-Namib shrubland (NA99-M12), leg. S.
van Noort & S. G. Compton. – MHNG, paratypes: 乆allotype (2 microscopical slides), Namibia,
Brandberg, plateau, 1960m, 21°10’50’’S 14°32’50’’E, 19-21.10.1998, yellow pan trap, leg. R.
Butlin & J. Altringham. 1乆(2 microscopical slides), Namibia, Brandberg, Hungorob Valley,
1180m, 21°11.40’S 14°31.69’E, 5-16.IV.1999, Malaise trap, bushy Karoo-Namib shrubland
(NA99-M10), leg. S. van Noort & S. G. Compton.
DESCRIPTION: Male and female: See diagnosis of tribe and genus, with the
following additions. General colouration yellowish white to very light brown.
Compound eyes black. Wings transparent, veins light brown. Abdomen lacking hypo-
dermal pigment (examined after 6-7 years in alcohol); terminalia yellowish to very
light brown.
General morphology as described for S. strinatii (see Lienhard, 2000). Head
capsule slightly concave between lateral ocelli, compound eyes small (IO/D: 么3.0, 乆
2.6-2.9). Antenna thin and apparently very long (extrapolated from lengths of basal
flagellomeres, see measurements; all antennae damaged in the material available), the
basal three flagellomeres together somewhat shorter than body length (very similar
values for the antennae of the allotype, broken after f6 and f4, show that probably no
asymmetrical regenerative length growth occurred, see remark in Lienhard, 2004:
870). P4 with two simple, thin-walled conical sensilla in apical half. Wing venation as
in Fig. 9ab, R1 present in hindwing. Spine-like setae on tibiae and tarsi with distinctly
rounded tips. Pearman-organ of hindcoxa not differentiated, both midcoxae with a dis-
tinctly prominent hyaline tubercle on inner side. Trichobothrial pattern on legs typical
for Sensitibillini.
Female terminalia (Fig. 8ac): Epiproct and paraproct as in S. strinatii
(Lienhard, 2000: Fig. 29), the circular field of dense and long pilosity on paraproct
well-developed. Subgenital plate entirely membranous, except for sclerotized rims in
zone of fusion with ovipositor valvulae; posterior part of subgenital plate triangular,
with subacute apex, almost completely covered by basal parts of ovipositor valvulae,
the latter touching each other medially. Ovipositor valvula laterally articulated near
anteroventral angle of clunium, ventromedially fused with subgenital plate in a sclero-
tized rim; anterior margin of clunium prolonged into a broad membranous ventral fold
459
NEW AFRICAN SPELEKETORINAE

on the valvula. Distal process of ovipositor valvula slightly curved, with a long claw-
like apical spine, one external spine-like seta in distal half and several such setae in
basal half, two or three of them on ventral side of the process. Basal part of valvula
with a transversal row of subapical dorsal setae and some ventral setae, a particularly
long one near rounded posterointernal margin. Spermapore situated in a small mem-
branous posteriorly rounded cap, spermathecal duct running through the eye of a
simple needle-like acessory sclerite, duct relatively long but not distinctly spirally
curled. Spermathecal wall, near origin of duct, with a large kidney-shaped, weakly
C. LIENHARD
460
PLATE 1
Sensitibilla strinatii Lienhard, female paratype, hindleg. (A) Second article of hindtarsus with
trichobothrium situated dorsally on slightly thickened central zone (dorsolateral view, base of
article near bottom of photo); the trichobothrium is actually an erect filiform hair (cf. Fig. 5e),
its artificially curved appearance on the photo results from the treatment of the leg for SEM
examination. (B) Base of trichobothrium of hindtarsus with adjacent setae and campaniform
sensillum, same view as A. (C) Ditto, dorsal view. (D) Socket of tibial trichobothrium, sensillum
broken but insertion point visible. SEM micrographs made by J. Wuest (MHNG).

sclerotized plate (its greatest width about 500 μm) sparsely covered by very fine
denticles and bearing a pair of heavily sclerotized teeth directed to the lumen of the
spermatheca and connected to each other by a narrow somewhat sclerotized band (in
461
NEW AFRICAN SPELEKETORINAE
FIG. 8
Sensitibilla brandbergensis sp. n., female: (a) Spermatheca containing two spermatophores, with
kidney-shaped sclerotized area of spermathecal wall, spermathecal duct not illustrated. (b) Apex
of third article of hindtarsus, only one claw illustrated. (c) Genitalia, ventral view, scale 0.2 mm:
Ovipositor valvulae with ventrolateral parts of clunium, subgenital plate and, observed in situ
through ventral membranes, spermapore and spermathecal duct with accessory structures and
kidney-shaped sclerotized area of spermathecal wall (compare with Fig. 8a).

one paratype female one of these teeth not developed). Spermatophores elongately
pear-shaped (Fig. 8a).
Male terminalia: Epiproct and paraproct simple (cf. Fig. 9e). Hypandrium
simple and almost colourless (Fig. 9c). Phallosome (Fig. 9d) with a pair of foliaceous
sclerites, anteriorly divergent, much enlarged in middle, posteriorly each with a well-
developed lateral lobe and a narrow internal branch; these branches medially fused and
forming a narrow aedeagal arch.
C. LIENHARD
462
FIG. 9
Sensitibilla brandbergensis sp. n., male holotype (a-d): (a) Forewing, scale 1 mm. (b) Hindwing,
same scale. (c) Hypandrium. (d) Phallosome, ventral view, scale 0.2 mm. – Sensitibilla roessin-
gensis sp. n., male holotype (e-f): (e) Epiproct and left paraproct. (f) Phallosome, ventral view,
same scale as Fig. 9d.

MEASUREMENTS: Male holotype. BL = 1.4 mm (strongly shrunk); FW = 2.6 mm;
HW = 1.4 mm; F = 600 μm; T = 1000 μm; t1 = 350 μm; t2 = 100 μm; t3 = 125 μm. –
Female allotype. BL = 2.3 mm (somewhat expanded); FW = 2.7 mm; HW = 1.5 mm;
F = 630 μm; T = 1040 μm; t1 = 350 μm; t2 = 105 μm; t3 = 125 μm; flagellomeres
(left/right): f1 = 490/480 μm; f2 = 510/535 μm; f3 = 525/550 μm.
ETYMOLOGY: The specific epithet refers to the type locality, Brandberg, the
highest mountain massif of Namibia.
DISCUSSION: S. brandbergensis is easy to distinguish from S. strinatii and
S. roessingensis by its smaller size, by the almost complete absence of any pigmenta-
tion and, above all, by the very characteristic genitalia of both sexes (see also key,
above). The type locality of S. brandbergensis, the Brandberg massif, is situated in
western Namibia, north of the town Swakopmund. S. brandbergensis has not been col-
lected in caves, as were most of the other Sensitibillini treated in this study, but in semi-
desertic shrubland, in Malaise traps and once in a yellow pan trap. Nothing is known
on its biology and it is not unlikely that these minute insects live in soil crevices, from
where they regularly come out during the night. The almost complete absence of any
pigmentation also points towards such an edaphico-nocturnal mode of life, which is not
fundamentally different from life in caves.
Sensitibilla roessingensis sp. n. Figs 3g, 9ef
TYPE MATERIAL: NMN, holotype 么(3 microscopical slides), Namibia, Swakopmund
District, Rössing Wes Cave (in cave), SE 2214 Db, 10.VIII.1995, leg. E. Marais.
DESCRIPTION: Male (female unknown): See diagnosis of tribe and genus, with
the following additions. General colouration yellowish to light brown. Compound eyes
black. Wings transparent, veins light brown. Abdomen with some brown hypodermal
pigment, pattern not clearly visible (examined after 10 years in alcohol), but essen tially
consisting of some segmental transverse bands; terminalia yellowish to light brown.
General morphology as described for S. strinatii (see Lienhard, 2000).
Compound eyes small (IO/D 2.9). Antennae broken after f1 and f2. P4 with two simple
thin-walled conical sensilla in apical half (Fig. 3g). Both forewings damaged, R1
present in both hindwings. Hindwing relatively long (1.3x greatest width of forewing).
Spine-like setae on tibiae and tarsi with distinctly rounded tips. Pearman-organ of hind-
coxa not differentiated, both midcoxae with a distinctly prominent hyaline tubercle on
inner side. Trichobothrial pattern on legs typical for Sensitibillini.
Male terminalia: Epiproct and paraproct simple (Fig. 9e). Hyandrium simple
and almost colourless (cf. Fig. 9c). Phallosome (Fig. 9f) with a pair of somewhat
spindle-shaped sclerites, anteriorly divergent, posteriorly each with a weakly
developed rounded lobe and a narrow internal branch; these branches curved towards
midline of phallosome apex but not fused into a continuous aedeagal arch, medio apical
lobe of phallosome deeply notched.
MEASUREMENTS: Male holotype. BL = 2.2 mm; HW = 1.6 mm; F = 720 μm; T =
1260 μm; t1 = 470 μm; t2 = 125 μm; t3 = 150 μm; flagellomeres (left/right): f1 =
540/530 μm; f2 = – /540 μm.
463
NEW AFRICAN SPELEKETORINAE

ETYMOLOGY: The specific epithet refers to the type locality, Rössing Wes Cave.
DISCUSSION: The type locality of Sensitibilla roessingensis is situated in western
Namibia, on the Namib Desert plains, about 30 km from the town of Swakopmund. It
seems rather unlikely that S. roessingensis could be the unknown male of S. strinatii,
described from Arnhem Cave in central Namibia. The specific diversity observed in
Sensitibillini suggests that these isolated and widely separated populations belong to
different species, even if they are closely related in view of their general morphology.
S. roessingensis is apparently slightly smaller than S. strinatii (T = 1.5 mm in the latter)
but has relatively long hindwings (in S. strinatii hindwing length only very slightly
exceeding greatest width of forewing). The forewing length of these species could not
be compared, because both forewings are damaged in the holotype of S. roessingensis.
In the holotype of S. strinatii the proximal P4 sensillum is slightly lobate (Lienhard,
2000: Fig. 8), in the holotype of S. roessingensis it is simple (detail in Fig. 3g), but this
difference is of doubtful taxonomic value. An additional argument not to assign tenta-
tively the male from Rössing cave to S. strinatii is the fact that the latter is the type
species of the genus. The definition of the genus could become problematic due to such
an unclear concept of the type species.
GENERAL DISCUSSION
PHYLOGENETICS
Due to the symplesiomorphic presence of an archaic wing venation, the extant
Prionoglarididae may be considered as “living fossils” (see Introduction). However,
the different clades of this family are characterized by striking autapomorphies and
surprising specializations unknown elsewhere in Psocoptera. Characters of Priono -
glaridinae have been treated by Lienhard (1988, 1998, 2004). In the following some
characters of Speleketorinae are discussed with regard to the phylogeny of this sub-
family.
The presence of trichobothria on legs, unique in Psocoptera (see also below),
has been considered as an important synapomorphy of Speleketorinae (see Lienhard,
2000, 2004), but it may also be interpreted as an adaptive homoplasy related to the
particular biology of these generally cavernicolous psocids. However, the monophyly
of Speleketorinae is also supported by molecular data (see Yoshizawa et al., 2006) and
by the slight but almost identical extent of metamorphosis of their mouthparts, in
particular the lacinia, during adult moult (see Lienhard, 2004). Therefore the presence
of leg trichobothria is here also considered as an autapomorphy of this subfamily. Each
tribe is characterized by a particular arrangement of trichobothria on the leg segments
(see key above and Lienhard, 2000: figs 17-24). Most elements of the characteristic
trichobothrial pattern in adults are already present in nymphs (at least in later instars,
first instars not examined) so that these can easily be assigned to a tribe, in spite of the
very similar habitus of all prionoglaridid nymphs. It is difficult to decide what kind of
trichobothrial pattern should be considered as plesiomorphic within the subfamily. The
presence of a tarsal trichobothrium in Sensitibillini, unique in insects (see below), may
be an indication that the Sensitibillini pattern has to be considered as apomorphic
compared to the Speleketorini pattern. However, each pattern could be an autapo -
C. LIENHARD
464

morphy of the respective tribe with regard to an unknown initial pattern of their
common ancestor. It is interesting to see that in both clades, Speleketorini and
Sensitibillini, 2-3 trichobothria per leg are generally present; in Sensitibillini they have
“migrated” to the distal segments (tibiae and hindtarsus), whereas in Speleketorini they
can be found on the more proximal segments (trochanters and femora). In bugs
(Hemiptera: Heteroptera), where leg trichobothria have almost certainly evolved
several times independently, they are present on coxae, trochanters and femora (Schuh,
1975) (occasionally trichobothria-like setae also occur on tibiae in some semiaquatic
bugs, see Moller Andersen, 1982). According to Schuh (1975) the Heteroptera, like the
Arachnida, seem to be disposed to the multiple evolution of these structures, whereas
leg trichobothria are unknown elsewhere in insects. The example of the Speleketorinae
shows that leg trichobothria have also evolved in some basal Psocodea, the sister-group
of the Condylognatha (i.e. Thysanoptera and Hemiptera) within the Paraneoptera (see
Yoshizawa & Saigusa, 2001). See also discussion on Funcional Morphology (below).
The Speleketorinae (or perhaps the Prionoglarididae in general) could also be
characterized by a reduced number of antennal segments. The normal trogiomorphan
antenna has more than 20 segments (i. e. scapus, pedicellus and at least 18 flagello -
meres); however, a slightly reduced number (19 segments) has been mentioned by
Yoshizawa et al. (2006) for an undescribed species of Psyllipsocidae. In
Prionoglarididae the antennae are always very thin and long and therefore broken in
most of the material available. I am not aware of any published number of antennal
segments of a complete antenna in Prionoglaris, and I could not find any complete
antenna in the material of this genus at my disposal (MHNG). In Siamoglaris the
antenna is more than 10-segmented (Lienhard, 2004: 870) but the exact number of
segments remains unknown. Mockford (1984: 170) observed three complete antennae
with a variable number of segments (7, 10, 15) in Speleketor. Lienhard (2000: 874)
reported one complete 13-segmented antenna in a female of Sensitibilla strinatii (i.e.
last flagellomere slightly tapering to a regularly rounded tip, bearing a conspicuous
terminal sensillum). In Afrotrogla maraisi one complete antenna with 11 segments has
been mentioned in the above description. Maybe the reduced and apparently variable
number of antennal segments could also constitute an autapomorphy of the subfamily
Speleketorinae, or even of the whole family Prionoglarididae. However, more flagel-
lomere counts of undoubtedly complete antennae are needed to confirm the taxo nomic
value of this character.
The Sensitibillini are characterized by the synapomorphic structure of their
female ovipositor, i. e. external valvulae with a strong distal process and ventrobasal-
ly fused to subgenital plate to form a functional unit (see also below). The genus
Speleketor has relatively plesiomorphic female genitalia, as described by Yoshizawa et
al. (2006) for Trogiomorpha. However, this genus is characterized by the autapo -
morphic structure of the phallosome, having its basal sclerites anteriorly fused (phal-
losome anteriorly open in Sensitibillini, as usual in the suborder Trogiomorpha), and
by the autapomorphic presence of a row of small spines on anterior face of the fore -
femur. Another possible autapomorphy of the Sensitibillini is the absence of the pore-
bearing processes of the phallosome, which probably belong to the groundplan of the
Trogiomorpha (see Discussion under Sensitibillini above, where two additional wing
characters of minor importance are also discussed).
465
NEW AFRICAN SPELEKETORINAE

Within Sensitibillini, the genus Afrotrogla is characterized by highly complex
structures associated with the spermapore and by an extremely simplified phallosome
(see also below). In addition, females of this genus have a dorsal pair of long curved
hairs subapically on the third article of the hindtarsus and some long backwards-
directed sternal setae near the midline in the basal half of the abdomen. All of these
characters are probably autapomorphies of Afrotrogla.
The genus Sensitibilla is characterized by the particularly tight basal fusion of
the ovipositor valvulae with the subgenital plate, so that the posterior part of the latter
becomes entirely membranous, being completely covered by the valvulae. Two other
autapomorphies of this genus are the absence of M2 in the hindwing and the reduction
of the number of thin-walled conical sensilla on P4 (2 in Sensitibilla vs 5-7 in other
prionoglaridids, see Fig. 3).
The high species diversity of Sensitibillini (i. e. six species, each from a
different locality, all collected by non-specialists) in the relatively sparse material
known from southern Africa indicates that these psocids are probably highly diver -
sified in this region, especially in caves, but possibly also outside caves (see collecting
data of Sensitibilla brandbergensis). I am sure that further sampling in southern Africa,
and especially in Namibia, will significantly increase our knowledge of this interesting
group of Psocoptera.
FUNCTIONAL MORPHOLOGY
Genitalia: The possible biological significance (digging organ?) of the parti -
cular ovipositor valvulae and of their partial fusion with the subgenital plate was
briefly discussed by Lienhard (2000) for Sensitibilla. The fusion, unique in Psocoptera,
is also present but less developed in Afrotrogla. The conspicuous porus (probably a
glandular opening) on the subgenital plate of Afrotrogla maraisi is also a highly
specialized structure. Its function is unknown, but it possibly forms a functional unit
with the pair of lateral stylets present on the subgenital plate of this species (see Fig.
6ef). The porus opens into a digitiform invagination of the subgenital plate and is sur-
rounded by a series of stout setae. Some very fine hyaline hairs (length 3-10 μm) could
also be observed in the lumen of the porus. This pilosity has probably a protective
function against intrusion of dust etc. into the porus. Structures similar to this porus and
to the stylets have never been observed in Psocoptera. They may play a role in ovi -
position by producing a protective secretion and distributing it on the surface of newly
laid eggs. However, the absence of the porus and of the stylets in Afrotrogla oryx and
in Sensitibilla shows that these structures are not essential parts of the functional unit
“ovipositor valvulae – subgenital plate”, present in all Sensitibillini. The unusual
tuft(s) of long sternal setae basally on the abdomen of females of Afrotrogla and the
pair of long curved subapical hairs on their hindtarsus (both absent in males) probably
also play a role in reproductive biology.
The membranous vesicle associated with the spermapore and its complex
accessory structures, present in females of Afrotrogla, are also unique in Psocoptera.
These structures are counterbalanced by an extreme simplification of phallosome
sclerites in this genus. In A. oryx the phallosome sclerite and the accessory structures
to spermapore are of very similar width (cf. scales to Figs 4g and 5c). It seems likely
C. LIENHARD
466

that the otherwise relatively complex trogiomorphan phallosome structures are here
functionally replaced by the complex female structures associated with the sperma-
pore. According to Klier (1956) the pincer-like pair of parameres in male Trogio -
morpha clasps the evaginated spermapore (opening of spermathecal duct) of females
during the long-lasting copulation (often more than two hours) and is responsible for
the close grip of male and female genitalia during sperm transmission. In Afrotrogla
this role may have been transferred, at least partially, to the complex set of sclerites
present near the opening of the spermathecal duct in females, in view of the reduction
of the phallosome sclerites to a simple and rigid aedeagal arch. In this context it is
interesting to note that in Sensitibilla the much more complex phallosome, bearing a
pair of movable sclerites, is paralleled by a very simple spermapore sclerite.
Trichobothria on legs: These trichobothria are very fine, but relatively rigid,
long and erect filiform hairs inserted in special sockets. They have briefly been
discussed by Lienhard (2000), who mentioned that they are probably vibroreceptors
sensitive to air currents and low frequency air vibrations (sound) and may be inter-
preted as adaptations to cave life. Some SEM micrographs are here presented for the
first time (Pl. 1); they show the shape of the deep pit-like trichobothrial socket and the
differences between the latter and the socket of a normal tactile hair. The particular
trichobothrial pattern of Sensitibillini has been described in the diagnosis of the tribe.
The presence of a trichobothrium on the second article of the hindtarsus (Pl. 1ABC) in
nymphs and adults of all Sensitibillini is of some general interest, because tarsal
trichobothria seem to be unknown elsewhere in insects (Schuh, 1975 and Schuh in
litt.). Trichobothria are known from different body parts in insects, but on legs they
have only been found in some Heteroptera families: In Miridae, Gerridae and Veliidae
trichobothria regularly occur on coxae, trochanters and femora (Schuh, 1975), but
never on tarsi (occasionally trichobothria-like setae are seen on tibiae in some semi-
aquatic Heteroptera, see Moller Andersen, 1982).
The trichobothrium on the second article of the hindtarsus of Sensitibillini is
situated dorsally on the thickened central part of the article, in a zone of granular
cuticle, and it is always accompanied by a campaniform sensillum (Pl. 1BC). Such an
auxiliary sensillum could not be observed near the tibial trichobothria. Similar
campaniform sensilla, which are sensitive to slight deformations in the cuticle, have for
instance been observed near cercal trichobothria of the cricket Gryllus bimaculatus
(see Barth, 1986: fig. 11e). No histological examination of these tarsal trichobothria
was made, but the central thickening of the second article of the hindtarsus (Pl. 1A)
indicates that the neurological equipment of this specialized sensillum is particularly
space consuming. All tarsal articles without trichobothria, of all pairs of legs, are of
normal cylindrical shape in Sensitibillini, as is the case in Speleketor and in Priono -
glaridinae.
ACKNOWLEDGEMENTS
I am very grateful to Eugene Marais (NMN) for the loan of all unidentified
psocids in his care, to Patrick Schmitz (MHNG) for transporting this material from
Windhoek to Geneva, and to Kevin Johnson (Illinois Natural History Survey,
467
NEW AFRICAN SPELEKETORINAE

Champaign) and Edward Mockford (Illinois State University, Normal) for placing at
my disposal some specimens of Speleketor irwini and S. flocki, respectively. Many
thanks also go to Edward Mockford and Peter Schwendinger (MHNG) for reading the
manuscript and making valuable suggestions, and to Randall T. Schuh (American
Museum of Natural History, New York) for providing general information on tricho -
bothria in insects. Jean Wuest and Florence Marteau (MHNG) are acknowledged for
producing the SEM micrographs and for assembling the plate.
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