Myrmicaria fumata (Santschi)
Type location Ivory Coast (Myrmicaria nitida Stitz
var. brunnea, n. var., Santschi, 1915c: 254, worker;
redefined as variety fumata Santschi, 1916d: 242, raised
to species by Santschi, 1925c: 160), from near Dimbroko, by Posth;
subspecies linearis (Santschi, 1925c: 161, illustrated,
worker) from Zaïre, collected at Bokala by R. Mayné;
worker only described (see Bolton, 1995)
.
Santschi's (1915c) description is at
.
Santschi (1925c) examining a single worker from Dimbroko, Ivory
Coast, apparently the specimen of his 1915 description, had
the following description (most of the comparison being with natalensis)
-
TL 5.6 mm. Colour dark brown red; shiny. Sculpturation of head as
in natalensis but occipitum with more numerous (12-13) and
more parallel rugae. The median carina and the two adjacent rugae
are closer together and more distinct; transverse ridge on vertex
more distinct and sinuous. Alitrunk sculpture distinctive with the
median carina extending back across the two faces of the
mesonotum; and the bordering rugae extend forward onto the
pronotum; being strong and parallel bifurcating anteriorly towards
the pronotal anterior border and anastomosing with their
neighbours. Inter-rugal spaces are smooth on each side of the
median ruga but a little striated around the promesonotal suture
and inequally rugose in the outer areas of the pronotum. The ridge
delimiting the faces of the mesonotum is somewhat advanced
medially. Sides of thorax with spaced striations, with large
smooth spaces, specially posteriorly. Both pedicel nodes with
several rugae. Funiculus striated. Remainder smooth together with
the tarsi and base of the gaster. Erect pilosity rust coloured,
much shorter and sparser.
Head more rectangular, the eyes nearer the posterior border.
Clypeus smooth subcarinate. Funiculus segments shorter. Pronotum
narrower and less transversely convex, sides more clearly edged.
Promesonotal suture well defined. Lobes of mesonotum and propodeum
similar in profile. Petiole node as in striata but
remainder as natalensis. |
His
earlier description (1915c) of it as "M. nitida var.
brunnea) was -
TL 5.6; brownish as gracilis Stitz. Shiny. Rugae on head
slightly stronger than on striata Stitz. Median ruga of
promesonotum well marked, bifurcated on anterior of pronotum as in
nitida. Propdeum dorsum very convex, smooth and shiny.
Petiole nodes shiny with feeble longitudinal rugae. Base of gaster
feebly reticulate (punctate in nitida). Head more
obviously rectangular, posterior and lateral borders straighter.
Thorax relatively slimmer. Propodeal spines slightly arcuate, and
divergent, rectilinear and horizontal in profile. Petiole slightly
longer and higher. Single worker from near Dimbroko, Ivory
Coast, Posth, 1910.
Santschi (1933b: 105), reporting 6 workers collected tending
aphids on cotton at Ibadan, Nigeria, noted the rugae were
quite variable on the pronotum and occipitum; the median line on
the mesonotum does not always descend on the declivity but is
bifurcate; the head and middle of the gaster are brown; TL
5.2-5.6; the second segment of the funiculus is a little longer
than the third which is as short as in foreli.
Bernard (1952) described this as a rare form known from Congo
and Guinea. Four workers were collected at N'Zo (a dry
forest area) by Lamotte. A further record was of a single queen
taken at Oubangui (location?) by A. Hollande, which extended its
distribution eastwards.
Santschi's (1925c) description of subspecies linearis
WORKER
TL 4.5-7.5 mm.
The main difference (from Santschi's key) are - colour a lighter
red brown, gaster often more. Pronotal rugae more numerous and
less well-defined. Propodeal dorsum raised and slightly concave
anteriorly. Also no well-defined ridge between dorsum and
declivity of mesonotum.
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While collating distribution records (March 2006), I realised
the identification I had from Bolton (1978, in litt.) of
Nigerian specimens as striata was almost certainly wrong
and that what I had studied, drawn and described was fumata.
That is West African as opposed to
Myrmicaria
striata which is from southern Africa.
Nigeria specimen (as Myrmicaria striata in
Taylor, 1980a: 9). WORKER. TL 5.57 mm, HL 1.24, HW 1.24, SL 1.03,
PW 0.90
Colour dark brown, shiny. Head and alitrunk, especially the
dorsum, are longitudinally rugose. Mesonotum with a lamellate
lateral margin. Propodeal spines moderately long, acute and flat
to down-turned. Petiole and postpetiole with rounded nodes.
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In Nigeria it was ground nesting, preferring bare,
insolated soil (pictured left). Will construct sunken runways in
soil surface. At the Cocoa Research Institute of Nigeria, Idi
Ayunre, it was fairly common, on 0.1-1.0% of cocoa trees, tending
aphids and stictococcids on cocoa flowers and pods, and
constructing tents of "mortared" soil (pictured right).
Some of the tents were associated with cocoa black pod infections,
it was frequently on the trees together with Camponotus
acvapimensis (Taylor & Griffin, 1981). In other cocoa
areas of western Nigeria it appeared to be much less common.
Earlier from CRIN, perhaps on > 0.25% of cocoa in pkd
collections from two cocoa blocks, W13/2 and W18/1 (Booker 1968),
and Eguagie (1971) found it at Ilugun near Ibadan.

Lévieux (1983a) mentions it (as striata) as one
of the two genus members populating the savannah in Ivory
Coast, where its nests were hardly noticeable from the
surface, being hidden under ground. He commented that little else
was known of its biology. |
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