George Karithi inspected the tomato crop on his farm on the south of Nairobi, Kenya’s capital, meticulously, turning the leaves up and down.
After a few minutes of checking the leaves of the crops, he heaved as disappointment registered on his face.
The farmer had sprayed the crop three days earlier against Tuta absoluta, a ravenous moth that normally attacks the plant.
Yet, as he checked the plants, he realized that it was the same pest that was ravaging the crop.
“How many times will I spray?” he asked dejectedly, noting later that he had sprayed the crop four times earlier with different chemicals.
He had harvested the crop once and had expected four more harvests but with the pest attack, even the second appeared a distant dream.
His predicament is shared by hundreds of other farmers growing horticultural crops across the east African nation.
But Tuta absoluta is not the only pest that they have to grapple with, it is among the deadliest though and most emboldened.
Others are fruit flies, which attack fruits like oranges, mangoes, watermelons and avocados, while whiteflies and aphids and False Codling Moth (FCM), ravages citrus, various kinds of pepper, flowers, avocados, macadamias and French beans, all which are export crops.
Agricultural experts have blamed the increase in the severity of the pests to the changing weather pattern, which has increasingly become erratic.
After months of a cold spell in Kenya that started in May and ended in September, temperatures are currently averaging 26 degrees Celsius, a new high, up from 24 degrees Celsius.
The high temperatures offer a perfect environment for breeding of pests like Tuta absoluta, whiteflies, fruit flies and FCM.
“It is the weather that is causing all the trouble. At 26 degrees Celsius, it takes a few days for the pests to multiply and thrive,” said Beatrice Macharia of Growth Point, an agro-consultancy.
The optimum temperature for high pest breeding is 25 degrees Celsius, said Macharia, adding that in such conditions, females lay up to 800 eggs over her life span, the highest.
The State of the Climate in Kenya 2019 report from the meteorological department released recently notes that the country’s temperatures are rising faster in response to global warming and may average 32 degrees Celsius by 2050 if mitigation measures are not taken.
“Mean temperature for the country has been increasing steadily. The spatial extent of high temperatures is expected to increase up to the year 2050,” warns the report.
During a recent cold spell, Kenyan farmers battled mainly diseases like blight and Downey mildew but with the dry weather comes pests.
Kenyan farmers lose a significant portion of their harvest to pests, which are of great economic importance.
For instance, the fruit fly losses are estimated at 50 billion shillings (462 million U.S. dollars) annually, according to the government’s Horticultural Crops Directorate.
On the other hand, FCM, which is native to sub-Saharan Africa, has seen crops from Kenya rejected in export markets.
The EU considers FCM a quarantine pest, thus, any product containing the moth is rejected.
Some of the pests Kenyan farmers are currently grappling with are not native to Africa. Tuta absoluta is said to have originated from South America, moved into Africa and came to Kenya through Ethiopia, according to researchers at Egerton University.
“The problem is that if we use excessive chemicals, the produce would be rejected yet pheromone traps are not working effectively, especially if the pests are many,” said Moses Ng’ang’a, a farmer in Murang’a, central Kenya.