Accepted: Dec-2011 Research Article THE DISTRIBUTION OF MAIZE STEM BORERS IN CROSS RIVER STATE, NIGERIA. Okweche, Simon Idoko and Umoetok, Sylvia B. A Department of Crop Science, Faculty of Agriculture, Forestry and Wildlife, P. M. B. 1115, University of Calabar, Nigeria. *Corresponding author: Tel - +234 -70 -3496-7125 E-mail address: idokosi@yahoo.com ABSTRACT : Field experiments were conducted to determine the distribution of stem borers in two agro-ecological zones of Cross River State, Nigeria. The experiments were conducted Akamkpa (rainforest agro-ecological zone) and Bekwarra (guinea savanna agro-ecological zone) during the 2009 and 2010 cropping seasons. The survey shows that species of Busseola fusca, Sesamia calamistis, Eldana saccharina, Chilo partellus, and Coniesta ignefusalis were found to be prevalent in the maize fields in the two agro-ecological zones of the state. Busseola fusca was however found to be significantly (p<0.05) more (17.741 per plant for early season and 26.667 for late season) than the other stemborer species (Sesamia calamistis 4.482 (early) and 4.926 (late),Eldana saccharina 2.259 (early) and 2.815 (late), Chilo partellus 3.444 (early and late) , Coniesta ignefusalis 1.889 (early) and 1.482 (late) in Bekwarra (guinea savanna agro-ecological) zone of the state while Sesamia calamistis population (15.963 (early) and 25.519 (late) was significantly (p<0.05) higher than other stemborer species (Busseola fusca 3.074 (early), 4.667 (late), Eldana saccharina 2.889 (early), 2.519 (late), Chilo partellus 4.296 (early), 4.482(late), Coniesta ignefusalis 0.963 (early) and 3.222 (late) in Akamkpa (rainforest agro-ecological) zone. Keywords: Stem borer species, population, agro-ecological zones, Guinea savanna, rainforest. INTRODUCTION Maize (Zea mays L.) is a cereal crop in the family Poaceae. It is perhaps the most completely domesticated of all cereals (Benz, 1994,) and essentially a crop of warm countries with adequate soil moisture (Adeyemi, 1969). It originated from South America where it was taken to all parts of the world (Galinat, 1992; Gonzalez, 2001). Modern maize is considered to have evolved from Teosinte (God’s corn) than from an early Mesoamerican maize called Chapalote or a Tripacum species (Doebley et al., 1990; Brenneman, 2001). Due to remarkable diversity of vegetative types, maize is the predominant and widely distributed cereal crop followed by sorghum (Sorghum bicolor) and millet (Pennisetum glaucum). Maize production is threatened by pests and diseases (Adeyemi, 1969). FAO (2008) observed that pest related losses in the field and storage play a contributory role in keeping cereal production below quantities demanded for utilization by rapidly expanding livestock industries and increasing human population in Nigeria. International Journal of Plant, Animal and Environmental Sciences Page: 82 Available online at www.ijpaes.com