The damage potential and preferential host of Cylas puncticollis Boh. were studied on cotton, Gossypium hirsutum L.; sweet potato; Ipomoea batatas and wild potato weed, Ipomoea eriocarpa on the field in screen cages and potted experiment in 2003-2006 at Sangere, Yola. Two varieties of cotton, SAMCOT 8 and AFCOTT-BENIN seeds were sown in 2003-2005 infested with 5 pairs of C. puncticollis in a completely randomized block design in three replications. Results obtained showed that caged (protected) gave higher yield in g/plant on SAMCOT 8 (43.67, 50.00 and 52.33) and AFCOTT-BENIN (50.33, 46.67 and 52.33) from 2003-2005 respectively. While caged and artificially infested gave lower yield of (38.80, 40.33 and 43.00) and (39.67, 34.33 and 38.00) for SAMCOT 8 and AFCOTT-BENIN respectively. Percentage reduction in yield was higher on AFCOTT-BENIN (21.17, 25.57and 26.80) compared to SAMCOT 8 (12.93, 19.10, 17.80) in same years respectively. Average number of fruiting bodies formed per plant when artificially infested with C. puncticollis on AFCOTT-BENIN (3.33/plant) compared with SAMCOT 8 (2.33/plant). However, the potted experiment carried out in 2006, showed that, I. batatas had yield loss of up to 95.93% and cotton bolls were not developed to maturity (bolls did not form lints).The leaves of cotton were not damaged by the weevils, but sweet potato damaged leaves was 46.95% which was less compared to I. eriocarpa with 54.90 %, but there was no significant difference at p=0.05.The weevils preferred Ipomoea leaves and the fruiting bodies of cotton
Keywords: Cylas, Fruiting bodies, Gossypium, Ipomoea eriocarpa, Percentage, Sweet potato
