A not of Resurgence of the Cotton Stemborer Sphenoptera gossypii Conte as a Serious Pest in the Irrigated Schemes in Sudan

Abstract

this study was conducted to investigate complaints by farmers in New Halfa
Agricultural Corporation (NHAC), Gezira Scheme, Rahad and Suki agricultural schemes
about wilting, drying and death of cotton plants during the 2012-2013 season which was
the first season for planting the genetically-modified Bt cotton (CN-CO2). A survey was
conducted and showed drying and death of young plants and wilting of older ones. A
longitudinal section of the stem revealed the presence of white worms of up to 3 cm in
length and white shiny pupae, together with coleopteran beetles. The insect was
identified as Sphenoptera gossypii. The damage was mainly in the variety CNCO2 but
individual plants of the local varieties Hamid, Abdeen and Barakat were also infestation.
The highest percentage of infestation was 30% in NHAC while the average infestation
was 2% to 3% in the Gezira scheme and was little in the Rahd scheme. The stem borer
was a serious pest of cotton in the 1920s and 1903s but as a result of clean-up campaigns
and adherence to technical guidelines the local varieties, except Sakel, could survive
unaffected. Introduction of the extremely susceptible variety (CNCO2) in large areas in
the irrigated schemes, which are plentiful of the pest, led to serious damage to the crop.
During October 2012, farmers from New Halfa Agricultural Corporation
(NHAC) complained of drying, wilting and death of cotton plants in their
fields; the incident was especially higher in the introduced genetically
modified Bt cotton variety (CN-CO2) than on the local variety "Hamid".
The season (2012-13) ranked first, for commercial planting of the Bt
cotton in NHAC, and other irrigated schemes in Sudan. Thus, the Bt
cotton was blamed as a causative of the incident. The CN-CO2 seeds