| The ability of honey bees, Apis mellifera and bumble bees, Bombus impatiens to vector the fungal agent Beauveria bassiana to canola and greenhouse peppers to control the tarnished plant bug (TPB), Lygus lineolaris and the western flower thrips (WFT), Frankliniella occidentalis was investigated. Factors affecting acquisition of B. bassiana by honey bees were studied in the laboratory. For vectoring studies, a dry formulation consisting of fine corn flour (45--90 mum) and conidia was used. Possible effects of B. bassiana on honey bees were evaluated in the laboratory using caged workers and in the field using honey bee hives. B. bassiana caused high mortality for caged bees when applied at high concentrations, but was safe for honey bee hives under field conditions. Vectoring of B. bassiana to canola, Brassica rapa and B. napus by honey bees was evaluated using screened cages in the greenhouse and in the field. Experiments with bumble bees and greenhouse sweet pepper, Capsicum annum were conducted using cages inside greenhouse compartments. The bees effectively vectored the dry formulation to canola and greenhouse sweet pepper as indicated by large amounts of B. bassiana detected on leaves and flowers of both crops as well as on the captured TPB and WFT. Mean mortalities of TPB collected from canola caged with honey bees and B. bassiana ranged between 30 to 56% compared to 9 to 22% in the controls. Mean mortalities of TPB and mean infection rate of WFT collected from greenhouse peppers caged with bumble bees and B. bassiana ranged between 34 to 45% and 35 to 40% compared to 9 to 15% and 2--3% in the controls, respectively. These results indicate that bees provide a novel way of applying microbial control agents for pest control in the field and in greenhouses that integrates different agro-ecosystem components i.e. pollinators, biological control agents and pollination for pest management. |
