Voodoo wasps that could save the world Genetic breakthrough could enable scientists to unleash armies of insects on deadly crop pests

They are so small that most people have never even seen them, yet "voodoo wasps" are about to be recruited big time in the war on agricultural pests as part of the wider effort to boost food production in the 21st century.


The wasps are only 1 or 2 millimetres long fully-grown but they have an ability to paralyse and destroy other insects, including many of the most destructive crop pests, by delivering a zombie-inducing venom in their sting.

Now scientists believe they have made the breakthrough that will enable them to recruit vast armies of voodoo wasps to search and destroy farm pests on a scale that could boost crop yields without polluting the wider environment with insecticides.
The researchers have decoded the full genomes of three species of parasitic wasp, which could lead to the development of powerful new ways of deploying these tiny insects against the vast range of pests that destroy billions of tonnes of valuable crops each year.

There are more than 600,000 species of parasitic voodoo wasps and they already play a critical role as a natural regulator of insect populations. However, scientists believe that the decoding of their genomes will open the door to new and better better ways of targeting them against specific pests.

"These genome sequences will be a major tool for agricultural pest control. Many people may not realise how dependent humans are on these tiny wasps which protect our food crops and save billions of dollars each year by reducing crop loss," said Chris Smith of San Francisco State University, a member of the research team.

The three wasps all belong to the Nasonia genus and are strictly speaking "parasitoid" species, meaning that they lay their eggs inside the paralysed bodies of other insects, keeping them alive long enough for the wasp larvae to grow and mature into adults as they feed off the living flesh of their "zombie" host.

"Parasitic wasps attack and kill pest insects, but many people don't even notice them or know of their important role in keeping pest numbers down. We owe them a lot. If it weren't for parasitoids and other natural enemies, we would be knee-deep in pest insects," said Professor John Werren of the University of Rochester, who led the study published in the journal Science.

"If we can harness their full potential, they would be vastly preferable to chemical pesticides which broadly kill or poison many organisms in the environment. We basically broadcast toxins into the environment – pesticides to control in a very non-specific way a large number of pests. As a result the environment is exposed to these toxins, and we are as well."

The scientists hope that deciphering the genomes of the Nasonia wasps will enable them to find the insect genes involved in directing a wasp to attack a specific insect, with the aim of understanding how to manipulate such attacks. The researchers also hope to identify the chemical nature of the venoms used by the wasps to paralyse their hosts, a development that could also lead to new drugs for human medicine.

Parasitoid wasps are already used as natural pesticides. Last year, for instance, scientists in the US released thousands of parasitic wasps to attack the olive fruit fly, which is decimating the olive groves of California. The wasp is harmless to people, pets and plants.

Scientists also believe that knowing the genomes of the Nasonia wasps will help in the fight against human diseases that are carried by insects. It may be easier to control the disease-carrying insect using the parasitic wasps, rather than targeting the disease itself