Safe sex is about to replace pesticides in an environmentally brilliant solution to human health and agricultural pest problems – if only we can get over our fear of technology. Let me explain.
Mosquitoes, not great white sharks, are the biggest killers of humans. Pesticides are becoming less effective as insect resistance increases. One company is trying to change all that. The one thing nature (and pests) cannot do without is sex. Oxitec, a company of which I was a shareholder and is now owned by Intrexon, may be on the brink of a revolution.
The company produces identifiable and genetically sterile male insects. These insects are released and mate with wild females whose eggs will not hatch. Farmers can trap agricultural pests in their fields, monitor the presence of sterile males and either buy more sterile males or more pesticides to maintain their crop. I know which makes more sense.
This is not about wiping out an insect species. Every animal on the planet has its role in nature (except perhaps humans). Releasing sterile males is only effective if pest reduction is in a localised area as insects do not generally travel large distances. One released sterile male will only neutralise one female egg producer, thus only interrupting the production cycle locally and for a single insect lifecycle – typically six weeks or so. Sterility is the only genetic trait you cannot inherit. If your parents were sterile – you would never have been born. So sterility is not ‘catching’ and therefore will not wipe out the target insect.
The company started by producing a sterile strain of mosquitoes – Aedes aegypti- that carry dengue fever – a very debilitating disease for which there is no cure or antidote. Oxitec is now protecting whole villages in Brazil from this mosquito by reducing its local wild population using its sterile insect technique. Brazil has over 1 million cases of Dengue fever a year, resulting in some $400 million in healthcare costs, despite spending over $1billion on pesticides to combat the problem. Pesticides are in fact, the real problem. The fogging of whole streets and villages in Brazil with pesticides does reduce the mosquito population but also damages whole ecosystems. It kills the flies, ants and butterflies and therefore affects the birds and other animals that rely on them as a protein source.
Our indiscriminate over-use of pesticides to maintain crop production is an even larger environmental disaster. Insecticides are leaving fields devoid of life, whilst polluting our soils and water systems with chemical residues.
Oxitec is now busy working on sterile insect solutions for agriculture. Sterile olive flies, diamond backed cabbage moths, and cotton boll weevils are in development. Sterile versions of these insects will allow the monoculture of these crops to continue whilst taking out only specific, target pests – leaving other ecosystems intact and the environment a better place.
There are always negative perceptions around genetic modification. It is a technology, like nuclear power, that has beneficial and relatively safe applications from healthcare to power generation – as well as dangerous ones in the wrong hands. We must however get into perspective that we have genetically selected everything from dairy cows to chickens and fish to help feed humanity over the last ten thousand years. Of course one cannot selectively breed for sterility. Now that we have the technical ability to engineer a sterile insect solution that could one day replace our use of chemical pesticides, we should welcome that technology. Not to do so, would be like a cave-dweller shivering in the cold and damp because they were too frightened to harness the power of fire.
Lets get busy repairing the future.