Observations on the biology of Afrotropical Hesperiidae (Lepidoptera). Part 9. Hesperiinae incertae sedis: Zingiberales feeders, genera of unknown biology and an overview of the Hesperiinae incertae sedis
Author
Cock, Matthew J. W.
Author
Congdon, T. Colin E.
Author
Collins, Steve C.
text
Zootaxa
2016
4066
3
201
247
journal article
51187
10.11646/zootaxa.4066.3.1
efd9df5e-1439-4724-ae76-a219f7c3ce70
1175-5326
264653
680D0FB4-F3BC-4562-B214-631067287218
Xanthodisca vibius
Hewitson, 1878
This species is found from
Cameroon
to
Kenya
and south to
Malawi
(
type
locality
Gabon
) (
Ackery
et al
. 1995
,
Larsen 2005
). In
Kenya
, it is a scarce species restricted to Kakamega Forest, and perhaps other western forests. MJWC never saw the adult, but did once rear it from a caterpillar.
Food plants
.
Le Pelley (1959)
gives
Amomum
sp. as the food plant in
Uganda
, a record apparently repeated by
Sevastopulo (1975)
,
Kielland (1990)
and
Ackery
et al
. (1995)
. MJWC reared this species from
Aframomum zambesiacum zambesiacum
, the normal food plant of
Semalea pulvina
in Kakamega Forest. TCEC has reared this species from the Rondo Plateau, south-east
Tanzania
and at Kihansi, south central
Tanzania
, from
Aframomum
sp. The former may be the origin of the record of
Aframomum
in
Heath
et al
. (2002)
. It seems likely that the early record from
Amomum
should be referred to
Aframomum
.
Caterpillar
. MJWC reared this species once from the final instar from amongst a batch of
S. pulvina
caterpillars collected from Kakamega Forest
1 July 1990
(MJWC 90/70G). He did not notice any differences in the shelters or caterpillars at the time, and was surprised when one pupa produced a female
X. vibius
. Examination of the cast head capsule revealed no qualitative difference between these two species; the clypeus, frons, adfrontals and a stripe down the epicranial suture light brown; the rest of the epicranium rugose, the raised areas darker brown and the pits lighter brown; posterior margin basally pale; it measured 2.2 x
2.75mm
wide x high, almost exactly the same as that of the final instar of
S. pulvina
(2.2 x
2.7mm
).
TCEC has reared this species at Kihansi and the Rondo Plateau,
Tanzania
, from
Aframomum
sp. It can be seen that the caterpillar (
Figure 22
) does indeed resemble those of
S. pulvina
, but was noted to be more squat, green, and with a squared off anal plate with a dark transverse mark.
FIGURE 22
. Dorsal view of final instar caterpillar of
Xanthodisca vibius
collected on
Aframomum
sp., Rondo Plateau, Tanzania, 20 Mar 1998 [TCEC].
FIGURE 23
. Pupa of
Xanthodisca vibius
collected on
Aframomum
sp., Kihansi, south central Tanzania, 19 Nov 2006 [TCEC].
1
, dorsolateral view;
2
, lateral view.
Pupa
. The
18mm
pupa that MJWC reared is very similar to that of
S. pulvina
, but the most obvious difference is in the dimensions of the semi-circular body around the T1 spiracle: the central hole measured
0.67mm
across ventrally-dorsally, and the rim measured
0.5mm
across dorsally,
0.5mm
posteriorly and
0.28mm
ventrally. In addition (based on the emerged pupae of both) the pupa of
X. vibius
is more uniformly pale compared to that of
S. pulvina
; an irregular dark mark subdorsally between the T1 spiracles, another dorsolaterally on the anterior margin of T3, A1 and A4-A6; proboscis reaches to the end of the penultimate abdominal segment. The pupa took 19 days until the adult emerged. The pupa documented by TCEC from Kihansi (
Figure 23
) is similar, but is darker and the distribution of dark markings differs, suggesting there is probably significant individual variation in colouring.