Distribution and habitat preferences of Galápagos ants (Hymenoptera: Formicidae)
Author
Herrera Léon Baert Wouter Dekoninck, Henri W.
Author
Causton, Charlotte E.
Author
Sevilla, Christian R.
Author
Pozo, Paola
Author
Hendrickx, Frederik
text
Belgian Journal of Entomology
2020
93
1
60
journal article
302430
10.5281/zenodo.13710313
83b9d93e-6482-4509-82e7-d477e479612b
2295-0214
13710313
2612CE09-F7FF-45CD-B52E-99F04DC2AA56
Camponotus macilentus
Smith, 1877
(
ANTWEB
: CASENT0173216). (
Map 9
)
This endemic and nocturnal species is uncommon in the archipelago. It was collected for the first time by Charles Darwin in 1835 (
SMITH
, 1877
;
WHEELER
, 1919;
LUBIN
, 1984
). It is known mainly from dry areas and is rarely found in the humid zones. It is distributed on 13 islands and is known to nest under rocks, and in hollow twigs in dry branches of
B. graveolens
and
M. octogona
previously inhabited by termites (
WHEELER
, 1919, 1924). It has been observed collecting honeydew from scale insects on the trunks and stems of
Scalesia gordilloi
O. Hamann & Wiumand
and it has been reported visiting flowers of
C. lutea
,
C. molle
,
S. cordata
and extrafloral nectaries of
O. echios
and
J. thouarsii
(
MEIER
, 1994
;
BOADA
, 2005
;
MCMMULLEN
, 2011, 2012).
C. macilentus
has been collected from mangroves (
Rhizophora mangle
L
.,
L. racemosa
),
B. graveolens
,
C. galapageia
, under trees of
H. mancinella
, and in undergrowth (like
I. triloba
) and ferns. It has also been collected in areas dominated by
Psychotria rufipes
Hook. f.
,
Z. fagara
,
S. microcephala
,
C. pyriformis
and
P. juliflora
.
Camponotus macilentus
apparently is strongly associated with forests of
B. graveolens
(HWH, pers. obs.).
Recent sampling (on volcanoes Alcedo and Darwin) show that the species is abundant in better conserved areas.
Camponotus macilentus
could be threatened by invasive species on Baltra, Floreana, Española and
Santa Cruz
islands. It was collected for the last time on
Santa Cruz
in the Littoral Zone in 1996 and in the Humid Zone in 2001 and has not been found since then despite intensive collections in all vegetation zones (using a large number of collecting methods) over the last 12 years.
LUBIN
(1985)
suggested a probable displacement of
C. macilentus
due to the invasion of
Tetramorium bicarinatum
(Nylander, 1846)
during the Niño event of 1982–1983 on Española.
Camponotus macilentus
is extremely shy and prefers to escape fast when threatened. In natural habitats it is preyed upon by
T. stolzmanni
, a crab–spider present in littoral, dry and transition zones, especially in shrubs of
C. galapageia
(
LUBIN
, 1983
)
.
Camponotus macilentus
is a complex of at least 12 subspecies (
WHEELER
, 1919, 1924, 1933), that requires further study.