The role bees play in pollinating crops is well known, but bees can carry more than just pollen from plant to plant. Sometimes their cargo is hazardous. Bees can infect plants with disease. Honey bees, according to an article in Australasian Plant Pathology, “have been implicated in the spread of the fire blight pathogen (Erwinia amylovora), and may transmit other bacterial plant pathogens.” The diseases are carried from one flower to another and sometimes from one area to another. The practice of transporting hives between fields, counties and even provinces can lead to the spread of ‘bee-borne’ diseases.
Scientists started to explore a positive angle to the bee’s work. Researchers retrofitted bee hives so the bees would pick up Bacillus thuringiensis, a biological control, as they left the hive. The goal was to control the banded sunflower moth. The bees carried the Bt to various plants where it was consumed by the moth larvae. “The honey bee vectoring method gave better or equivalent control of the banded sunflower moth larvae than manual sprays [of B. thuringiensis], resulting in higher seed yields than manual sprays. The presence of honey bees also increased seed set which contributed to greater yield,” reports an article in Environmental Entomology.
Agriculture and Agri-Food Canada scientists experimented with bumble bees (Bombus impatiens) to transport “microbial control agents” to control greenhouse pests. “Greenhouse cage trials have shown that bee-vectored Beauveria bassiana can cause substantial mortality of Lygus, whiteflies, thrips and aphids (up to 80 per cent mortality) when tested on greenhouse tomato and sweet pepper.”
Now, a Canadian company is capitalizing on the busyness of bees. BVT, short for Bee Vectoring Technology (beevt.com) uses bumblebees to transport various materials to plants, particularly in greenhouses. They provide special bee hives that require the bees to walk through a tray of powdery substance, which sticks to their legs and is thereby carried to flowers throughout the greenhouse.
BVT uses the bees to carry “VT-CR7, an organic strain of a natural occurring endophytic fungus,” which doesn’t hurt plants but can control fungal pathogens including Botrytis and Sclerotinia (often responsible for root rot and damping off.) The company claims the substance also promotes plant growth. And while bringing these powders to the plants, the bee can still perform its age-old role of pollination.
- Janet Wallace