Butterflies of
Africa
Drury's Delight
Mesoxantha ethosea
DRURY, 1782
Family - NYMPHALIDAE
subfamily -
BIBLIDINAE
Tribe - EURYTELINI
Mesoxantha ethosea,
Bunso, Ghana
Introduction
The genus
Mesoxantha comprises
of a single species - ethosea. It
is a strange butterfly, unique in appearance, and is so atypical
for a Nymphalid that it was once considered to be a member of
the Lipteninae ( Lycaenidae ). It has now for a long time been
realised that it is actually a member of the Biblidinae - a
group of butterflies with over 350 species worldwide, the vast
majority of which are Neotropical. In the Afrotropical region
there 30 species, in the genera Byblia,
Ariadne,
Eurytela, Neptidopsis,
Sevenia and
Mesoxantha.
Mesoxantha ethosea is a largely west African species, found from Sierra
Leone to Cameroon and western Uganda.
Habitats
This species is found in primary and mildly degraded rainforest habitats, at
altitudes between about 100-800m.
Lifecycle
The larval foodplant is
Tragia ( Euphorbiaceae ).
Adult behaviour
Males can be found in two's and three's flying around favoured
trees, usually on hilltops or ridges.
They often perch on narrow branches, in a head downward posture,
with their wings half open; or sometimes on foliage, to await
passing females.
Males
frequently intrude into each other's territory, and when this
happens an aerial skirmish takes place, during which both
butterflies make a long series of clearly audible clicking sounds. This is
presumably their way of shouting "go away".
To my knowledge the only other species which behave in a similar
manner are the Hamadryas Cracker
butterflies of Central and South America. In
Hamadryas the
sound is produced as the butterflies take off, and is made by twanging a
pair of spiny rods at the tip of the abdomen
against bristles on the valvae ( the male's anal
claspers ). Only males can produce the sound, but both sexes can detect it
- their wings have tiny hollow cells covered in membranes which vibrate in
response to sound and stimulate nerve endings. The purpose of the sound is not
fully understood : it may
deter competing males from occupying the same territory, and may also act as a
trigger to initiate the first response from a female during courtship.
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