A survey of Palaearctic Dictynidae (Araneae). 1. Taxonomic notes on Dictynomorpha Spassky, 1939, Brigittea Lehtinen, 1967 and Lathys Simon, 1884
Author
Marusik, Yuri M.
Author
Esyunin, Sergei L.
Author
Tuneva, Tatyana K.
text
Zootaxa
2015
3925
1
129
144
journal article
10.11646/zootaxa.3925.1.9
98786b6c-26a1-4204-9967-e2190ecce616
1175-5326
243577
52C2B852-7814-4313-B18A-717241C81E4F
Brigittea
Lehtinen, 1967
, reinstated
Brigittea
Lehtinen 1967
: 219
, 360.
Brigittea
:
Miller & Svatoň 1978
: 9
.
Dictyna
:
Wunderlich 1987
: 224
.
Type
species
:
Aranea latens
Fabricius, 1775
[=
B. latens
].
Diagnosis.
Brigittea
is the only genus among Dictyninae with ctenidia on the male palpal tibia and a bipartite cribellum.
Comments
. The genus was created for eight species
B. latens
(Fabricius, 1775)
(♂♀, West Palaearctic),
B. civica
(Lucas, 1850)
(♂♀, West Palaearctic),
B. denisi
Lehtinen, 1967
(♂♀,
Niger
),
B. innocens
(O. Pickard- Cambridge, 1872) (♂♀, West Palaearctic),
B. turbida
(
Simon, 1905
)
(♀,
India
&
Sri Lanka
),
B. tullgreni
(Caporiacco, 1949)
(♂,
Kenya
),
B. vicina
(Simon, 1873)
(♂♀,West Palaearctic) and
B. umai
(Tikader, 1966)
(♂♀,
India
).
Lehtinen (1967)
created a table with characters for 23
Dictynidae
genera. According to this table,
Brigittea
,
unlike
Dictyna
,
has a bipartite cribellum, ventral boss and anterior teeth on the male chelicerae, and a spiraled structure of the vulva.
Miller & Svatoň (1978)
revised European
Brigittea
and provided an additional character that separates this genus from
Dictyna
– widely separated receptacles [contiguous in the
type
species,
D. arundinacea
(Linnaeus, 1758)
and related species].
Merrett
et al
. (1985)
, in a faunistic paper, doubted the validity of
Brigittea
stating that “
D.
[
ictyna
]
latens
was included in the new genus
Brigittea
by
Lehtinen (1967)
on account of its bipartite cribellum and palpal characters; this was followed by
Brignoli (1983)
, but since there seems to be some doubt about the validity of this genus we have decided to leave
latens
in
Dictyna
for the present”.
Wunderlich (1987)
used these arguments in favour of a formal synonymy of the two genera and suggested that this taxon be regarded as the “
Dictyna latens
-Gruppe”. He extended this group to eight species by adding
D. guanchae
Schmidt, 1968
and
D. agaetensis
Wunderlich, 1987
(currently these names are considered as synonyms).
However, while studying
Dictynidae
from
Kazakhstan
, we found additional characters which support the validity of
Brigittea
. The male palp in all Dictyninae and partially in Tricholathysinae has a very similar conformation; therefore somatic characters play an important role in the recognition of these genera.
The bipartite cribellum is known in only five genera of Dictyninae and was not reported in Tricholathysinae.
Brigittea
is the only genus among Dictyninae with ctenidia on the male palpal tibia and a bipartite cribellum. The cribellum of
Brigittea
has only one anterior row of setae (
As
), whereas the remaining cribellate area is covered only with fine spigots (
Fs
). This contrasts with that in
Dictyna
in which the anterior two-thirds of the cribellum is covered with setae and one third with fine spigots.
The male chelicerae each have a distinct baso-lateral tooth (
Bt
) in
Brigittea
(
Fig 33
) which is weakly developed in
Dictyna
. Such a tooth is found not only in the
type
species, but well documented for
B. innocens
(
IJland
et al
. 2012
: fig. 4) and
B. guanchae
(
Wunderlich 1987: fig. 590
) as well.
Brigittea latens
has also cheliceral teeth (
Ct
) lacking in
Dictyna arundinacea
(cf.
Figs 28, 33
). The cheliceral ridge (
Cr
) of the
type
species of
Dictyna
and
Brigittea
also differs in its length. Also, the profile of the chelicera in
Dictyna
is strongly concave (
Fig. 28
), while in
Brigittea
it is almost straight (
Fig. 33
) or convex (pl. IV, fig.
1 in
Miller & Svatoň 1978
).
The
type
species of both genera differ essentially in their structure of the ctenidia. In
Dictyna
,
ctenidia are set in separate alveoli, while in
Brigittea
, they are located in the same alveolus. The ctenidia in
D. arundinacea
have distinct micro-ridges which are lacking in
B. latens
. The tip of the lower arm of the conductor is also different in
D. arundinacea
and
B. latens
, but this difference is not important as the shape of this tip in
Dictyna
is very variable. More important differences are found in the shape of embolus. In
Dictyna
,
it is filamentous and the tip is gradually tapering, while in
B. latens
it is modified (
Fig. 36
). This character was overlooked by
Lehtinen (1967)
and
Miller & Svatoň (1978)
. A modified embolus might prove to be the “best” character that separates the two very similar genera
Dictyna
and
Emblyna
(
Lehtinen 1967
)
.
Equally, the epigynes of
D. arundinacea
and
B. latens
are entirely different in all respects.
Brigittea latens
has no epigynal sulci, which are present in all
Dictyna
sensu
stricto
.
Brigittea civica
and
B. vicina
have sulci, although they are much shorter than in
Dictyna
. The most significant differences lie in the shape of “receptacles”, which are contiguous in
Dictyna
and forming a V-shaped structure together with the ducts; in contrast, in
Brigittea
,
the receptacles do not touch each other and together with ducts form a spiraled (coiled) structure.
Based on the reasons mentioned above, we decided to resurrect
Brigittea
as a valid genus with following species:
B. latens
,
B. civica
,
B. innocens
,
B. vicina
and
B. guanchae
(Schmidt, 1968)
,
comb. n.
(ex
Dictyna
) from the Canary Islands. The latter species was attributed to the
Dictyna latens
group by
Wunderlich (1987)
.
Four species from Afrotropical and South Asian regions considered in
Brigittea
by
Lehtinen (1967)
(
D. denisi
,
D. turbida
,
D. tullgreni
and
D. umai
) remain in
Dictyna
. These species are not properly known and their descriptions lack information about a divided cribellum or modified chelicera.