Deadly moth meets match in net house

Daniel Agawo was on a usual field inspection tour of his chilli farm one evening last December when he received a call from the Kenya Plant Health and Inspectorate Services (Kephis) official.

“Maybe the crop officer wants more tonnage of the bullet chilli,” Agawo, the general manager at Jim’s Fresh Vegetables thought.

However, when the crop officer cleared his voice to deliver the message, Agawo was alarmed.

“Watch out your farm for False Codling Moth (Thaumatotibia leucotreta) outbreak, there might have been an invasion,” the officer warned. “The moth has the potential of munching the entire chilli farm into a bare land.”

Agawo, whose farm had harvested several tonnes of chilli for export to the European Union market, knew too well that the revelation could be a big blow to their fresh vegetable export business.

False Codling Moth is classified by the EU as ‘quarantine pest’, meaning farms invaded by the pest are never be allowed to sell to the lucrative market.

For the record, fresh vegetable exports to Europe were intercepted 29 times between January and June last year due to harmful organisms in a crackdown that placed Kenya on the EU quality watch list.

Horticultural Crops Directorate, the industry regulator, says that 17 out of the interceptions involved capsicum due to the moth.

“It was the first time I was experiencing such total crop waste. I had to seek clarification on the pest,” explains Agawo of the happenings on the farm located 5km from Isinya town, Kajiado County.

To curb the moth, the farm took a four-month break as it heavily invested in net houses as a pest management initiative.

Bearing a striking resemblance with a greenhouse, a net house is a sealed structure made of insect net (polyester fabric) designed to keep insects away from plants by physical exclusion.

In other words, it is a wall around the farm barring insects from accessing the crop. While greenhouses are made of polythene walls and roof, a net house is simply a polyester fabric with tiny holes — like those on a mosquito net.

“It is difficult to control insects such as moths in a greenhouse because the structures have wide ventilations at the top for regulating temperature and humidity. The ventilations can be a point of entry for insects to invade the crops,” Agawo explains.

A net house is also cheaper compared to a greenhouse, he added.

“Since we adopted the use of the net houses, we have roared back to chilli production. It was an expensive investment but we had to comply to access the EU market. Chilli export is our lifeline,” he says.

MAINTAINING HIGH HYGIENE LEVELS

Generally, controlling the dreadful pest revolves around three parameters namely awareness, monitoring and chemical interventions.

Different studies and trials conducted in the country by Kephis and implementing partners have shown that the pest is widespread across the country with Kirinyaga, Murang’a, Thika, Naivasha, Machakos and Kajiado counties recording high prevalence rates.

The most challenging bit with FCM is that most of the time the farmer does not know whether the pest is present in the greenhouse, experts say.

“We installed monitoring tools such as Crytrack, which lures or attracts the pest to help us in monitoring and early detection,” notes Agawo.

The attractants, Agawo says, use specific hormones to lure one gender to the trap where they get stuck.

“Managing the pest isn’t easy since they are nocturnal so they can only be detected through trapping using the lures.”

To monitor the pests, traps are placed about five metres from the growing areas which form the inner buffer zone.

However, once the presence of the pest is noted to be too high inside the traps, control through mass trapping or chemical interventions is then applied.

Maintaining high-level of hygiene on the chilli plot is also critical in insect and pest management, Agawo says.

Once hatched from the eggs, the larvae burrows into the rind of the chilli fruit. A discolouration appears at the point of entrance.

While inside they feed on the pulp, causing premature ripening and fruit drop.

“It bites the fruit when it is still young, so it is not easy to detect during early stages,” explains Agawo. Some of the varieties of chilli grown on the 100-acre farm are short, long and thin chillies, Bandai and serenade chillies.

From one hectare of bullet chilli, the farm harvests 40-50 tonnes and sell a kilo at Sh100.

“I get orders of about 12-15 tonnes a week but I am only able to meet half of that,” he explains.

Eric Ogumo, a crop protection expert, says that over the last two years, the pest incidence has increased due to the changing weather patterns.

“Although it has been around, FCM in now classified as an emerging pest because it is affecting chilli export from Kenya,” he said, adding that the pest has also shifted to rose flowers causing major losses to growers.