Management of the banana root borer (BRB), Cosmopolites sordidus (Germar; Coleoptera: Curculionidae), remains a challenge in banana and plantain production worldwide. Synthetic pesticides remain the most widely used solution while mycoinsecticides are increasingly being recommended. In this study, we selected indigenous isolates of Beauveria bassiana and Metarhizium anisopliae collected from plantain fields in Cameroon, and tested them in the laboratory for their viability, pathogenicity and virulence against all C. sordidus life stages. Of 13 isolates initially screened for spore germination and pathogenicity to adult weevils in conidial suspension of 3.2 × 108 conidia/ml, eight isolates with high to moderate germination and highest weevil mortality were selected for dose–response bioassays with four concentrations per isolate: 3.2 × 102, 3.2 × 104, 3.2 × 106 and 3.2 × 108 conidia/ml. The virulent isolates from adult bioassays were tested with eggs, larva and pupae in conidial suspension of 3.2 × 108 conidia/ml. Isolates performance depended on insect life stage with significantly high pathogenicity and virulence against larval, pupa and adult stages. The Beauveria isolate BIITAC6.2.2 caused the highest mortality rates followed by MIITAC1.1.5. Lethal times and lethal concentrations were relatively low for the three M. anisopliae isolates and three B. bassiana isolates which were the best isolates in almost all insect life stages. Apart from being effective in multiple life stages, these isolates were transmitted horizontally from one stage to another when eggs and pupae were treated. The implication of these findings for integrated management of the BRB, and potential biopesticides development and commercialization are discussed.

Cocoa mirids, Sahlbergella singularis and Distantiella theobroma, are the most economically important insect pests of cocoa in West and Central Africa, where they can cause up to 40% losses in cocoa yields. Sahlbergella singularis is the most common species in Cameroon and was therefore targeted in this study. During a two-year trial in 15 cocoa plantations in Ayos and Konye, in the Centre and Southwest regions of Cameroon respectively, the most effective colour white, purple or greenof sex pheromone traps was examined for integration into mirid management programmes. Similar temporal patterns in S. sahlbergella male trap catches were observed with all three colours, but the green trap caught more S. singularis