A locust being eaten inside out by the metarhizium fungi.Chinese factories are producing thousands of tonnes of a "green zombie fungus" to help fight the swarms of locusts plaguing east Africa.
Metarhizium is a genus of fungi with nearly 50 species – some genetically modified – that is used as a biological insecticide because its roots drill through the insects' hard exoskeletons and gradually poison them. In China it was named lu jiang jun, which means green zombie fungus, because it gradually turns its victims into a green mossy lump.
The need for metarhizium is particularly pressing in East Africa at the moment, where abnormally high levels of rainfall during the dry season allowed hundreds of billions of locusts to hatch in recent months. So far the swarms have devastated crops in countries such as Ethiopia, Kenya, Somalia and Uganda and are moving on to neighbouring countries.
The UN’s Food and Agriculture Organisation (FAO) has warned the situation could be the “worst in decades” and the resulting famine may affect 13 million people and cause international food prices to soar.
Scientists do not believe that the fungus will be enough to solve the problem – monitoring the outbreak and targeting their breeding grounds will be more important in the long-run – but if it proves effective it could be an important weapon to target future outbreaks.
In addition, it will take time to gauge the effectiveness, partly because each fungus will take several days to take effect and partly because of the sheer scale of the challenge; a single swarm in Kenya was estimated to contain between 100 billion and 200 billion locusts.
The locusts have also swept eastward into the Middle East, travelling up to 150km a day, and are moving closer to China now that they have now reached some of its neighbours, including India and Pakistan.
More about the insect-killing fungus
Chinese scientists first became interested in the green zombie’s potential in the 1980s after discovering that South Pacific islanders had been using them to kill insects on coconut trees.
Research by US scientists confirmed its effectiveness in the 1990s and the Chinese started importing the fungus from the United States and Britain. Their experiments led to the development of newer and deadlier strains and mass production started in the past decade.
Other fungi or bacteria can be used to fight locusts, and some laboratories are working with agricultural technology companies to modify their genes to turn them into more deadly or precise killers.
One genetically engineered species of microsporidia, another type of insect-killing fungus, for instance, can generate three times as many as the spores to those produced by nature species, according to a document from the China Association of Agricultural Science Societies last year.