Effective monitoring is the key to all insect pest management programmes. Understanding the dynamics of pest populations makes it easier to make the right treatment at the right time – maximising effectiveness. With RIDL or SIT, it is critical to be able to accurately determine whether insects caught in traps are released sterile ones or fertile wild ones. Wrongly identifying a wild insect as sterile means an infestation may be missed, while misidentification of a sterile insect as wild means that resources will be wasted dealing with a non-existent infestation.
Today, insects are marked with fluorescent dusts or food dye which are not always easily identified on insects recovered from field traps, and of course do not pass on to the next generation in the case of any incomplete sterility. Oxitec’s strains contain genetic fluorescent proteins that glow when viewed under certain filters. Because it is integrated into the insects’ DNA, the marker can always be detected, it won’t fade with age and it is inherited if offspring are produced. The fluorescent proteins are derived from marine corals or jellyfish and have been widely used as biological markers in organisms in all kingdoms with no adverse effects. They are non-toxic to the insects and to their predators. The markers can also be read by analysing DNA in the laboratory to provide a further tool for identifying the captured insect, guaranteeing complete accuracy. Oxitec is working with partners to develop equipment for simple field identification that can be automated.