Panic has gripped residents of Laikipia West after a swarm of insects believed to be desert locusts were sighted.
Suspected to have migrated from Laikipia North, the insects caused panic among maize farmers in Rumuruti, Gatundia and Marmanet areas.
"I was shocked to wake up in the morning and find the insects in my farm," said Ms Hannah Waceke, a farmer in Gatundia.
The farmers have called on both the county and national governments to move with speed and control the destructive pests.
"We are calling on the team that is spraying and controlling the insects to concentrate in these areas to avert damage," said Marmanet Ward representative Simon Kanyutu.
County Agriculture executive Lucy Murugi said Isiolo, Meru and Samburu counties would work with the national government, the private sector and the Northern Rangelands Trust (NRT) to contain the locusts.
"We contracted Farmland Aviation and they began aerial spraying last week along the Laikipia border with Isiolo and Samburu," said Dr Murugi.
On Wednesday, there were fears that the 'war on the locusts' may take longer after it was established that the pesticides being used in aerial spraying were ineffective.
A swarm of the destructive pests sprayed at Lentile Hills in Laikipia had by Tuesday moved on to Talle area in Isiolo County while another at Kachiuru area in Meru, sprayed on Sunday, was spotted moving towards Ndumuru area.
This forced a team of officials from the five affected counties to convene a meeting at Lewa Education Centre in Meru to discuss the effectiveness of the pesticides.
"The adult locusts are resistant to the pesticides and aerial spraying might not produce maximum results. We may shift to hand pumps and perhaps even source a more effective chemical," one of the representatives said.
Mr Salad Jillo, Isiolo's Agriculture chief officer, who is also the team's chairperson, confirmed that the pesticides were not effective and promised to share more information later.
Mr Jillo challenged universities to capture the insects within their respective areas and try out various chemicals on them to ascertain which one was most effective.
The swarms had by Sunday afternoon invaded Kipsing, Mariara and Serolipi areas in Isiolo, Meru and Samburu counties where spraying was done for two days.
The Ministry of Agriculture has already rolled out a two-day training for technical officers from eight counties in efforts to equip them with skills to monitor and control the insects.
Meanwhile, Kenya Forest Service (KFS) officials expressed concern the locusts could move to forest reserves. The locusts are feared to cause more harm if they attack broad-leaved trees, which could result in the death of entire forest plantations.
Reported by Steve Njuguna, Waweru Wairimu and Nicholas Komu