Thailand to release 250,000 wasps to fight South American invader

Thailand is to release a quarter of a million wasps to fight a South American insect wreaking havoc on the country’s cassava crops. The tiny parasitic wasps will be unleashed in Thailand’s northeastern province of Khon Kaen on Sunday in an attempt to control the pest outbreak. The invader, the cassava mealybug, sucks sap from the plants and causes them to shrivel, resulting in the loss of up to half the crop. The first colony of the wasps – which measure less than two millimetres – was carried by hand from Benin to Bangkok last year for testing and mass rearing. The Anagyrus lopezi wasp is said to have already shown itself to be a formidable natural enemy of the cassava mealybug in South America and sub-Saharan Africa, injecting their eggs into the mealybugs. When the eggs hatch, they kill the unsuspecting host from the inside out. Scientists said the wasps posed no threat to humans, animals, or other insects.