Ong' amo Georges, Le Rü Bruno, Dupas Stéphane, Moyal Pascal, Calatayud Paul-André, Silvain Jean-François. (2006). Distribution, pest status and agro-dimatic preferences of lepidopteran stem borers of maize in Kenya. Annales De La Societe Entomologique De France, 42 (2), p. 171-177. ISSN 0037-9271.
Titre du document
Distribution, pest status and agro-dimatic preferences of lepidopteran stem borers of maize in Kenya
Ong' amo Georges, Le Rü Bruno, Dupas Stéphane, Moyal Pascal, Calatayud Paul-André, Silvain Jean-François
Source
Annales De La Societe Entomologique De France, 2006,
42 (2), p. 171-177 ISSN 0037-9271
Lepidopterous stem borers are the main field insect pests that attack maize, Zea mays L. in tropical Africa. A survey was carried during the long and short rain cropping seasons of 2002/2003 across six main agro-climatic zones (ACZs) to determine the spatial distribution of important stem borer species in Kenya. A total of 474 visits were made in the seventy-eight localities conveniently chosen to represent each of the six ACZs. 189,600 stems were checked for infestation, of which 27,799 infested stems were destructively cut and dissected for stem borer larvae identification. An average of 1.4 stem borer larvae were recovered per infested plant. 54.5% of the recovered larvae were identified as Chilo partellus (Swinhoe) (Crambidae), 39.7% as Busseola fusca (Fuller) (Noctuidae), 4.5% as Sesamia calamistis Hampson (Noctuidae) and 0.8% as Chilo orichalcociliellus (Strand) (Crambidae). Minor species present included Eldana saccharina Walker (Pyralidae), Sesamia nonagrioides (Lefebvre) (Noctuidae), Sesamia cretica Lederer (Noctuidae), Sesamia sp. (Noctuidae), Sciomesa piscator Fletcher (Noctuidae), Busseola sp near phaia (Noctuidae), Chilo sp, Ematheudes sp 1 (Pyralidae) and Ematheudes sp 2 (Pyralidae). Farms were grouped into respective ACZs for statistical analysis and subsequent comparison of dominant species: Results indicated that B. fusca was the dominant stem borer species in high potential zones (highland tropics, moist transitional zone and moist mid-altitude) while the exotic C. partellus dominated smallholder farms in low potential zones (dry mid-altitude, dry transional and lowland tropical zone). Within each ACZs, there was evidence of variation in species proportions between seasons. These spatio-temporal differences in community structure are discussed in terms of agro-climatic biological adaptations.
