A synopsis of present knowledge of the Simuliidae (Diptera) of the Canary Islands, including keys to the larval and pupal stages
Author
Crosskey, R. W.
Author
BÁez, M.
text
Journal of Natural History
2004
2004-08-20
38
16
2085
2117
http://dx.doi.org/10.1080/0022293032000140958
journal article
10.1080/0022293032000140958
1464-5262
4658794
Simulium (Simulium) intermedium
Roubaud
Material from breeding sites
Gomera
:
Site
G2—1„(z) (
12 April 1974
) (
MB
)
and 3„(z), 1”(z),
32 pupae
,
115 larvae
(
6 June 1990
) (
RWC
)
.
Site
G4—1„(z) (
6–7 June 1990
) (
RWC
)
.
Site
G5—1„(z), 1”(z),
23 pupae
,
37 larvae
(
6 June 1990
) (
RWC
)
.
Site
G6—
2 pupae
,
12 larvae
(
5 June 1990
) (
RWC
)
.
Site
G7—
2 pupae
,
3 larvae
(
5 June 1990
) (
RWC
)
.
Site
G8—2„(1z) (
29 March 1978
) (
MB
)
.
Gran Canaria
:
Site
GC3—larvae present (
29 March 1994
) (
BM
/
ANN
)
.
Site
GC4—
95 immatures
in sample (
29 March 1994
) (
BM
/
ANN
)
.
Site
GC5—
1 larva
(
24 April 1996
) (
RWC
)
.
Site
GC6—
1 immature
in sample (
28 March 1994
) (
BM
/
ANN
)
,
3„(z), 3”(z),
47 pupae
,
67 larvae
(
24 April 1996
) (
RWC
)
.
Site
GC7—larvae present (
29 March 1994
) (
BM
/
ANN
)
.
Site
GC8— larvae present (
28 March 1994
) (
BM
/
ANN
)
.
Site
GC9—
4 pupae
,
21 larvae
(
30 March 1995
) (
RWC
)
,
3 pupae
,
14 larvae
(
1 April 1995
) (
RWC
)
,
128 immatures
in sample (
19 November 1995
) (
BM
/
ANN
)
,
5 pupae
,
22 larvae
(
21 April 1996
) (
RWC
)
and 2„(z),
3 pupae
,
6 larvae
(
20 March 1997
) (
RWC
). Site GC10—
172 immatures
in sample (
29 March 1994
) (
BM
/
ANN
). Site GC12—larvae present (
28 March 1994
) (
BM
/
ANN
). Site GC13—1„(z) (
31 December 1987
) (
MB
)
and
3 immatures
in sample (
28 March 1994
) (
BM
/
ANN
)
.
Site
GC17—
810 immatures
in sample (
30 March 1994
) (
BM
/
ANN
)
.
Site
GC18—larvae present (
30 March 1994
) (
BM
/
ANN
)
.
Site
GC19—larvae present (
31 March 1994
) (
BM
/
ANN
)
.
Site
GC20—
62 immatures
in sample (
31 March 1994
) (
BM
/
ANN
)
.
Site
GC21—
153 immatures
in sample (
1 April 1994
) (
BM
/
ANN
)
.
La Palma
:
Site
LP1—
3 larvae
(
17 April 1981
) (
RWC
)
.
Site
LP2—3„(z), 1”(z),
37 pupae
,
126 larvae
(
16 April 1981
) (
RWC
)
.
Tenerife
:
Site T1—
1 pupa
,
1 larva
(
12 April 1991
) (
BM
/
ANN
/
MB
)
.
Site T12—
11 pupae
,
79 larvae
(
10 June 1990
) (
RWC
)
and
2 larvae
(
10 November 1991
) (
BM
/
ANN
/
MB
)
.
Site T14—2„(1z) (
24 March 1983
) (
MB
),
11 larvae
(
9 April 1983
) (
RWC
)
.
Site T15—
17 larvae
(
22 December 1970
) (
HD
)
.
Remarks
This species is widespread in much of Europe and North Africa, occurring also in the
Balearic Islands
and Madeira. The previous report (Crosskey, 1988b) recorded breeding sites in Gomera, La Palma and Tenerife, but not Gran Canaria, from which only wild-caught adult flies were at that time known; since then,
S. intermedium
immatures have been collected at 15 of the 21 simuliid breeding sites located in Gran Canaria—where it can be regarded as the commonest species present. The female
holotype
of
S. intermedium
, from Güimar in Tenerife, has been discussed by Crosskey (1965); it possesses the shining black (instead of dull grey pollinose) frons that is the diagnostic character separating the female of
S. intermedium
from that of other members of the
Simulium ornatum
group.
Several fixed larvae collected (RWC) on
18 April 1981
from the Los Tilos aqueduct in La Palma were sent to the late K. H. Rothfels at that time for cytological analysis but failed to make usable preparations. However, the chromosomes of larvae from two samples collected (RWC) in
1995 in
the Barranco de la
Mina (Gran Canaria)
have now been briefly reported upon in a comparison between the chromosomes of
S. intermedium
larvae in northern
Sweden
and the Canary Islands (Adler
et al
., 1998: 374). Chromosomes in the Swedish population differed from the Gran Canaria population by lacking two fixed inversions on chromosome IIL. The significance of this is uncertain because of the paucity of data from elsewhere, only Post (1979, as
nitidifrons
) in Britain having researched the chromosomes in detail. Ideally any future investigation should include material from Tenerife, as this island is the
type
locality, and could show differences in the polytene chromosomes from populations in Gomera and Gran Canaria.