Effect of Interspecific Competition between the Larger Grain Borer, Prostepltanus truncatus (Horn) (Coleoptera: Bostrychidae) and the Maize Weevil, Sitopltilus zeamais (Motschulsky) (Coleoptera: Curcullonidae) on Grain Damage and Progeny Production in Stored Maize (Zea mays L)
SADIKU. B.T., KEMABONTA, K.A., AND MAKANJUOLA, W. A.
Department of Zoology, University of Lagos, Akoka -Yaba, Lagos, Lagos State, Nigeria
Nig . J. Entomol. 33: 37 -45 (20 17)
DOI: 10.36108/NJE/7102/33(0150)
ABSTRACT: This study investigated the effect of the interaction between Prostcphanus trtlllcoflls(Hom)(LGB) and Sitophilus zeatnais (Motschulsky) (MW) on grain damage and progeny production in stored maize. 50g maize grains replicated four times was placed into 250ml Kilner’. 10 and 5 pairs of 1-3 day old adult LGB and MW were introduced into each Kilner” jar in single and simultaneous infestation and placed in a completely randomized design (CRD) in the laboratory at 27± 1oC and 75-80% RH. There was increase in the number of emerged insects from F 1to F2 for both insects. The percentage change in the number of emerged LGB was 18.7% and 9.0% in single and simultaneous infestation respectively, while in MW, it was 13.2 % and 16.8% respectively. There was a significant reduction in the reproductive performance of the two insects during simultaneous infestation when compared with single infestation The weight loss and damage caused by LGB were 4.31 and 7.21 % while that for MW were 2.55 and 5.85% respectively for single infestation and 5.0 and 9.67% for simultaneous infestation at Fl. For F2 generation weight loss and damage to grains was 6.90 and 11.14% for LGB and 3.78 and 7.79% for MW during single infestation while for simultaneous infestation it was 8.33 and 13.33‘%.There was a positive correlation between the number of LGB and MW and the grain weight loss and weight damage of stored maize. The result of the study indicated the potential of LGB and MW to cause huge weight loss and damage in maize grains which can lead to serious storage losses.
Keywords: Prostcphanus truncutus. Sitophilu» zcantctis. grain damage. reproductive performance, grain weight loss.