| dc.description.abstract | Sesamia calamistis
Hampson (Lepidoptera: Noctuidae) is one of the indigenous stem borer pests
associated with maize (
Zea mays
L.) and sorghum [
Sorghum bicolor
(L.) Moench] (both Poaceae) in
Africa. Its pest status varies across the continent and this has been attributed to variation in diet
breadth and ecological preferences among populations. Its larvae were found on 12 plant species
during a study initiated at four sites (Muhaka, Mtito Andei, Kakamega, and Suam) in Kenya to
estimate its diet breadth and genetic population structure. Ten of the infested plant species belonged
to the family Poaceae [
Echinochloa haploclada
(Stapf) Stapf,
Eleusine corocana
L.,
Eleusine jaegeri
Pilg.,
Panicum deustum
Thunb,
Panicum maximum
Jacquin,
Pennisetum purpureum
Schumacher,
Setaria verticillata
(L.) P. Beauv.,
Sorghum arundinaceum
(Desvaux) Stapf,
S. bicolor
, and
Z. mays
];
the other two were Cyperaceae:
Cyperus distans
L. and
Cyperus dives
Delile. Combined with collections
from other African countries (Uganda, South Africa, Benin, Ghana, Nigeria, and Togo), comparisons
of partial cytochrome
b
sequences revealed the presence of 68 haplotypes that differentiated into
clades I and II. In Kenya, the two clades colonized different regions, except in Mtito Andei where they
co-existed. Individuals from Mtito Andei could be separated based on their host plants: clade I with
14 haplotypes was found mainly on maize (78.6%), whereas clade II with 10 haplotypes was found
mainly among wild host plants (63.6%). Detection of divergence among these clades with cytochrome
b
suggests that their evolutionary separation may have taken place about one million
years ago. This article discusses the potential implication of this differentiation for the management
of
S
.
calamistis
as a pest of maize and sorghum in Africa | en |
