TITLE:
Comparative Morphometry of the Sitophilus zeamais Motschulsky Populations (Coleoptera: Curculionidae) Infesting Yellow Maize in Four West African Countries
AUTHORS:
Adiouma Georges Robert Jacques Sarr, Cheikh Abdou Khadre Mbacké Dia, Tofféne Diome, Pape Mbacké Sembene
KEYWORDS:
Morphological Groups, Sitophilus zeamais, Maize
JOURNAL NAME:
Advances in Entomology,
Vol.10 No.1,
January
6,
2022
ABSTRACT: Sitophilus zeamais is a primary pest of stored maize, which can cause
quality and quantity losses. Maize is cultivated in several West African
countries where different agro-climatic and agro-ecological conditions exist.
These conditions could influence the Sitophilus zeamais morphology. Thus, the purpose of this study is
to identify the Sitophilus zeamais morphological groups in the four countries. This was carried out through the
morphometric study of 30 male Sitophilus zeamais individuals taken from the yellow maize in each
country, by measuring with a binocular magnifying glass, 16 variables of the
different tagmas belonging to the insect. Subsequently, statistical analyses
were firstly carried out with the raw measurements, such as the principal
component analysis, in order to extract the contribution of the variables on
each factorial axis and to visualise the correlations between the variables.
Taking the case of the transformed measurements, in addition to the principal
component analysis, a discriminant factorial analysis was carried out to find
out the best factor for gathering individuals according to their morphology, a
confusion matrix to summarise the individual’s reclassification in order to deduce the good and
bad classification rates, and an ascending hierarchical classification which
consists of gathering the individuals according to their similarity and
separating them according to their dissimilarity using the truncation method.
Therefore, five morphological groups were identified. However, the existence of
these morphological groups would not be linked to agro-ecological, climatic
conditions and to the geographical remoteness between countries.