Bacteria May Offer Natural Plant Pest Control

New research at York has revealed so-called ‘Jekyll and Hyde’ bacteria, suggesting a novel way to control pests without using insecticides. Researchers at the University of York studied the relationship between plant-dwelling insects and bacteria.

A research team, at the University of York, has uncovered what they refer to as a Jekyll and Hyde bacteria, this discovery may result in a means to control insect pests without using insecticides. The team studied the relationship between plant-dwelling insects and the bacteria that live in them. What they found was an unexpected interaction between the insects and the bacteria. "These findings offer exciting new opportunities to control aphids and other pests without using insecticides." Professor Angela Douglas. Plants do not set out a come and get it buffet for insects; the reality is that many insects are only able to feed on the plants due to the existence of a third party which is a symbiotic bacteria that lives in the insects and provide extra nutrients. The team was examining the interactions between black bean aphids and their associated bacteria, when they discovered an intriguing new category of organism that they dubbed ‘Jekyll and Hyde’ bacteria. Black bean aphids are able to live on a number of different plant species. In most situations, their internal bacteria are harmless or even beneficial; this is their ‘Jekyll’ side. However, on certain plants, the relationship between insect and bacteria changes with the microscopic organisms exhibiting a disruptive ‘Hyde’ side. The insects continue to grow and reproduce very slowly and the bacteria themselves proliferate to very high densities in a short time. The team conducted further experiments which have suggested that the factor triggering this strange change is the composition of nutrients in the plants where the creatures live. The teams’ results were published in the Proceedings of the Royal Society B and may point the way to new methods to control aphids and other insect pests. Douglas said: "We now have the basis to explore precisely how these insect pests control their bacteria — and perhaps to develop ways to make the bacteria ‘turn nasty’ on the insects. These findings offer exciting new opportunities to control aphids and other pests without using insecticides."