Insect pests can have an insidious impact on communities, spreading disease and ingraining poverty. None is more devastating than Africa’s tsetse fly, also known as the poverty insect.
Some 39 African countries are infested with the insect, whose bite spreads the parasite that produces sleeping sickness in humans and a similar disease in livestock, known as nagana. Of the infected countries some 32 are low-income food deficit countries and 29 are among the least developed countries of the world.
“If you take a picture of tsetse distribution in Africa it matches very well with the poorest countries in the world,” explained Rafael Argiles-Herrero, a scientist with the International Atomic Energy Agency (IAEA), who is part of a team working on a project to eradicate the insect.
The project uses gamma radiation - hence the IAEA’s involvement - to sterilise male tsetse flies reared in captivity, before releasing them into the wild by dropping them from drones. These sterile males then compete for mates with their wild counterparts, making it more difficult for the females to breed, thus driving down the population.
“The wild population will decline progressively,” said Argiles-Herrero. “The survivors are overwhelmed with more sterile males every week, at a ration of 10:1, so in the end the population cannot recover and can eventually be eradicated.”
The work is being tested in Ethiopia, where infestation affects 200,000 km2 of the most fertile land in the country. It is an initiative to control tsetse-transmitted trypanosomosis in Ethiopian agrarian regions in accordance with the Ethiopian government’s Growth and Transformation Plan (GTP) and the Country Program Framework (CPF).
“Lowlands infested with tsetse are not in use for agriculture, so there is high potential for these areas,” said Argiles-Herrero.
The use of drones in the project has been developed to tackle the high cost of releasing them by aircraft. The sterile insects are transported in temperature-controlled pods then released at a height of 300 metres. The low temperature keeps the flies inactive, but they wake up as they are dropped and start flying before they hit the ground.
The UAV, currently in the testing phase, overflies the target areas following a predefined path track. Along the flight, the automated release machine drops the insects at predefined rates according to its position. The UAV has a minimum endurance of 2 hours flying with the payload of 2kg at a cruise speed of 20 m/s. During the flight, the pod releases the boxes at predefined coordinates in the target area. 5,000 flies can be released per flight, covering an area of around 100 km2.
The first prototype of the UAS including the release system has already been produced and tested locally by Embention. In the coming months, it will be shipped to Ethiopia to be tested under real field conditions.