Crematogaster (Atopogyne) depressa (Latreille)
Type
location Guinea (Formica depressa, Latreille,
1802c: 268, illustrated, queen; Forel, 1910f: 5, male, no
description), collected from the Coast of Guinea, by Palisot de
Beauvois; subspecies adultera (Crematogaster depressa
Latr. var. adultera n. var., Santschi, 1915c: 252, worker)
from Congo, Brazzaville, by A. Weiss; and fuscipennis
(Crematogaster depressa Latr., var. fuscipennis n.
var., Emery, 1899e: 479, worker & queen; Forel, 1909b: 53,
male, no description; Santschi, 1910c, illustrated) from Cameroun
(no details); junior synonyms foreli (C. buchneri
For. subspec. foreli. nov. subspec., Mayr, 1895: 138,
worker; this has had various statuses, presently synonymized by
Bolton, 1995: 153) from "Slave Coast" - Guinea;
and, platygnatha (Formica platygnatha nov.sp.,
Roger, 1863a: 168, queen, with its junior synonym mandibularis
(Cremastogaster mandibularis nov. sp., André, 1889:
229, queen) from Sierra Leone (see Bolton, 1995)
.
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Latreille's (1802c) description of the queen is at
.
Roger's (1863a) description of platygnatha is at
.
André's (1889) description of the mandibularis
queen is at
.
Mayr's (1895) description of foreli is at
.
Emery (1899e) provided a drawing of the head of the major and the
variety fuscipennis (left). His description of the latter
is at
.
Santschi (1910c) in a comparison with Cr. julienni had the
drawing of the pedicel and mandible (below right). He also
commented on fuscipennis and described an ergatogyne
worker - at
(note the illustration clearly was wrongly labelled, the mandible
8e seems to be that of the female shown in 9b;
8c is the mandible of Cr. (Oxygyne) margaritae).
Santschi's (1915c) description of the dark brown adultera
is at
.
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Nigeria specimens (Taylor, 1979: 39) WORKER. Size very
variable TL 3.42-7.28 mm; largest HL 2.02, HW 1.80, SL 1.18, PW
1.00
Colour dark chestnut brown. Dense pilosity, few erect hairs and
only four on the postpetiole. Mandible of largest worker with a
concave masticatory margin. Alitrunk profile rounded except in the
metanotal groove area where it is often raised. Mesonotal carina
low. Propodeal spines acute fairly stout and straight, down curved
on the largest workers.
Wheeler (1922) included records from Senegal, Guinea
(Los Islands), Sierra Leone (Mocquerys), Ghana,
Nigeria (Lagos, Olokemeji and Ibadan, by F. Silvestri; Old
Calabar, by H. Brauns), Cameroun (Victoria), plus Congo
areas. Santschi (1935) noted a specimen of fuscipennis
from Kisantu, Zaïre, collected by R.P. Vanderijst,
i.1919. Forel (1909b, 1911f) reported Zaïre specimens
- foreli from Luki, by Dr Jullien, fuscipennis
from Kinshasa [Leopoldville] by Waelbroeck and Dr Dubois, and "Congo"
by Deleval.
From Guinea, Bernard (1952) described it as of the
western plains, on Mount Nimba found solely at Kéoulenta
and Yalanzou. |
A
common dominant species, constructing large carton nests on major
forest tree (see illustration from Wheeler, 1922, and "click",
below left). Forages widely from the nest site onto cocoa and any
other adjacent trees.
In cocoa surveys in Nigeria (where it was not separated
from Cr. africana) it was found on 10-12% of trees,
throughout the cocoa growing area (Taylor, 1977; Taylor &
Adedoyin, 1978). Earlier from CRIN, by Booker (perhaps on >10%
of cocoa in collections from two cocoa blocks, W13/2 and W18/1,
Booker 1968).
In Ghana, Strickland (1951a) found that at CRIG what he
describes as the depressa-buchneri group was more common
(218 collections) than africana (27 collections) but less
so than striatula (778 collections). Bolton (1970-71)
listed it as one of the six most common carton-nesting Crematogaster
species on cocoa (simply at CRIG or in Ghana is not clear) and
noted that it was a common species. Leston (1973) also regarded it
as a dominant. It was found in only one cocoa canopy sample by
Room (1971) but Majer found it in 13.2% of his 144 pkd samples at
Kade, with 300-400 workers per sample (1975, 1976a, b, c). Bigger
(1981a) lists a number of cocoa surveys and these have little depressa
other than at Kade (Majer's results). However, it since has been
described as widespread by Belshaw & Bolton (1994b), who found
it, as a 'tourist', in leaf litter samples at six locations in the
semi-deciduous forest zone.
Strickland (1951a) added that the depressa-buchneri
group was essentially African, from Ivory Coast east to
the equatorial forests of Sudan.
In Cameroun it was by far the most common species in the
Campo forest canopy
surveyed by Alain Dejean and colleagues. It occupied 87.4% of the
trees and 85% of the vines, and its colonies reached several
million workers. They felt the large ecological success of Cr.
depressa is probably due to its ability to nest on trees with
or without extra-floral nectaries (EFN). |
The
photomontage is of a specimen collected in Cameroun -
south-western tropical coastal forest area between Edéa and
Campo (McKey Wolbachia project) - Cameroon 06 from
location TM, 24 March 2001 (Transect Marigot - adjacent to EBO at
2°34.04' N 9°50.64' E), on soil and surface in forest
understorey. Other images can be seen in the folder at -
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The
photomontage is of a specimen collected in Ghana, by S Sky
Stephens, 2006. Other images can be seen in the folder at -
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The
photomontage is of a specimen from Congo, Brazzaville,
collected by Yves Braet & Eric Zassi. Other images can be seen
in the folder at -
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The
photomontage is of a major from the Central African
Republic, Dzanga-Sangha NP; 06.x.2008; Nuit; Camp 1; 04°22'19.4"
N 18°35'49.7" E 360 m; Bangui après la corniche
direction N'garagba; collector Philippe Annoyer, at
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The
photomontage is of a queen from the Central African
Republic, Dzanga-Sangha NP; 09.ii.2005 18h30-6h30; Camp 3; 02°50'03.0"
N 16°08'11.2" E 375 m; Sur plate-forme à 35 m du
sol dans un Terminalia (Terminalia superba, Combretaceae);
collector Philippe Annoyer, at
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