Evaluation on Potential of Wild Hosts As Trap Plants for Managing Gramineous Stemborers in Maize BasedAgroecosystem

Abstract

As part of habitat management system to control cereal stemborers, various wild hosts used as trap plants were studied during the dry season from November 2003 to March 2004 at Melkassa, central Ethiopia. Five wild hosts of the family Poaceae [Pennisetum purpurum (Schumach), Sorghum vulgare variety sudanense (Pers.), Panicum coloratum L., Sorghum arundinaceum Stapf, and Hyperrhania rufa (Nees)] were evaluated as trap plants in maize, Zea mays L.,-based agroecosystem. The results of the study showed that maize plots surrounded by all tested wild hosts had signiÞcantly lower mean percentage of foliage damage and stemborer density than maize monocrop plots 15 m away from the treatment blocks. Interestingly, mean foliar damage and stemborer density between maize plots surrounded by wild hosts and maize monocrop plots within the treatment blocks was not signiÞcant. Percentage of tunneled stalks was signiÞcantly greater in maize monocrop plots 15 m away from the treatment blocks than in maize plots surrounded by all tested wild host plant species. Moreover, the highest mean percentage of parasitism (62%) of Chilo partellus (Swinhoe) by Cotesia flavipes (Cameron) was recorded in maize plots surrounded by P. purpureum. Therefore, the Þndings revealed that these wild hosts have considerable merit to be used as trap plants in the development of strategies for managing cereal stemborers in maize crops.