They are the size of a pinhead and don’t even pack a sting, but these tiny wasps are cold-blooded killers nonetheless. They work as nature’s SWAT team, neutralising a pest that threatens to destroy one of the developing world’s most important staple foods — cassava.
The wasps are being released in Indonesia, the latest country threatened by the mealybug. It’s a chalky white insect shaped like a pill that’s been making its way across Southeast Asia’s fields for the past six years.
But unlike in Thailand, where infestations reached some 250,000 hectares (618,000 acres) of crops grown mostly as part of the country’s huge export business, cassava in Indonesia is a vital food source second only to rice. That makes the mealybug a serious threat to food security in Indonesia, which already has one of the region’s highest child malnutrition rates.
The parasitic wasps, or Anagyrus lopezi , need the mealybug to survive. Females lay their eggs inside the insect and as the larvae grow, they eat the bug from the inside out, slowly killing it until there’s nothing left but its mummified shell.
Scientists put 2,000 wasps into a holding cage at an affected field in Bogor, on the outskirts of Indonesia’s capital, Jakarta. They will be monitored to see how well they handle local conditions as they multiply to an expected 300,000 over the next month before being released into the wild to start their relentless killing spree.
It’s unclear how much damage mealybugs have already caused to Indonesia’s crops, but infestations have been reported on the main cassava-growing island of Java and in parts of Sumatra, said Kris Wyckhuys, an entomologist at the Colombia-based International Center for Tropical Agriculture, which is helping to coordinate the release.
Indonesia is one of the world’s top producers of cassava, planting around 1 million hectares (2.5 million acres) a year, half of which is eaten as a staple food across the sprawling archipelago of 240 million people.
Source of carbohydrates
The long, finger thin roots of the shrub-like plant are a major source of carbohydrates and provide an array of nutrients. Like the potato, cassava is a versatile starch that’s an essential part of daily meals across much of the developing world. In Indonesia it is boiled, fried, made into noodles, crackers and even cakes.