A new mechanism of insecticide resistance in Insects

Sofar, the only mechanism known to confer Insecticide resistance among insects is through evolutionary changes in the genomes of the insect pests. These changes in the genome confer resistance by altering drug target sites, up-regulation of degrading enzymes, and enhancing the excretion of the drugs.

Here is a report by a team of Scientists from Japan, headed by Professor Yoshitomo Kikuchi who report a new mechanism of insecticide resistance in Insects effected through the symbiotic bacteria which these insects hosts.

The pest insect commonly called, the bean bug Riptortus pedestris and the related stinkbugs host  symbiotic bacteria of the genus Burkholderia (Burkolderia)  in thier gut.

Burkholderia genus contains over 30  species, many of which are important human pathogens. This genus is formed of motile , non–spore-forming gram-negative rods and were  formerly classified as members of the genus Pseudomonas . One of the species Burkholderia pseudomallei - is called  'The Great Mimicker' and is a potential agent for bioterrorism.

Certain strains of Burkolderia strains are capable of degrading the insecticide, Fenitrothion. Professor Yoshitomo Kikuchi  and his team have found out that when they inoculated fenitrothion sensitive insect pests with fenitrothion-degrading symbiotic Burkholderia strains conferring resistance to the host insects against fenitrothion.

Further reading:
http://www.pnas.org/content/early/2012/04/19/1200231109.abstract

http://www.pnas.org/content/early/2012/04/19/1200231109.full.pdf+html

- Dr. P. Kumarasamy