The researchers at Warwick HRI, the horticultural research arm of the University of Warwick, have devised a hanging basket style dispenser full of a virus known to kill the larvae of codling moth. The dispenser is designed to protect the virus from the elements and also includes a strong source of codling moth pheromone. The pheromone draws in the moth hoping for a sexual encounter and the insect leaves frustrated but covered in the virus which it then passes on to other moths when it does manage to have an actual encounter with another real moth. This results in direct contamination of eggs laid by the pest or contamination of the site where the moth lays its eggs. The larvae are killed after eating the virus on the egg or plant surface. This brings two key benefits to fruit growers:
An end to spraying - Normally Growers wishing to use this form of virus warfare have to spray almost every element of an orchard to ensure the moths come into contact with virus. This is wasteful both of time and resources. By this method the moth themselves spread the virus in a very targeted way to other moths and prevents loss of populations of other beneficial insects such as the red spider mite which would occur if growers used pesticides.
Extended virus life - The virus does not fare well in direct sunlight. Growers who currently spray the virus find it quickly becomes ineffective and it has to re-sprayed several times in order to control the pests. By placing the virus in dispensers with a cover that shields the virus supply from direct sunlight one application of virus could serve for an extended period
Source:University of Warwick