Kenya needs advanced drone technology to contain the desert locusts devastating farms and grazing fields in different parts of the country, experts have advised.

According to Dr Muo Kasina, the chairman of Entomological Society of Kenya, the aircraft deployed by the Ministry of Agriculture to conduct aerial spraying are getting overwhelmed by the huge swarms.

"The government needs to get help from countries with advanced drone technology like the United States, Israel and Denmark to deal with the locust menace before it gets out of hand," said Dr Kasina.

Speaking to the Nation on Monday, the scientist explained that the aircraft are not able to access certain areas like deep valleys and mountain contours, where some of the locusts may be passing.

Dr Kasina said that despite the government's efforts to combat the locusts through aerial spraying, the numbers entering the country each day are overwhelming, hence the need to change strategy.

"So far we've detected more than 20 swarms entering Kenya at different points from Somalia. Each swarm has an estimated 80 million locusts covering between two and four kilometres," he said, adding this is the worst invasion in more than 50 years.

This seemingly unhindered movement of the pests has brought to question the effectiveness of the Sh230 million aerial spraying campaign spearheaded by the Ministry of Agriculture, with leaders calling for a review of the exercise.

However, Dr Kasina explained that aerial spraying is effective but the aircraft need to be increased to cope with the numbers.

The revelation of the overwhelming situation comes as the United Nations appealed for urgent international support as the desert locusts threaten to devastate farming regions across East Africa.

The UN's Food and Agriculture Organisation (Fao) has called for an emergency funding of $70m (Sh7 billion) to combat the locusts through sustained aerial spraying.

"This has become a situation of international dimensions that threatens the food security of the entire region," said Qu Dongyu, Director-General of Fao.

"Authorities in the region have already jump-started control activities but, in view of the scale and urgency of the threat, additional financial backing from the international donor community is needed so they can access the tools and resources required."

Farmers in the eight affected counties have adopted traditional methods to deal with the locusts, including beating drums with hopes that they will scare them away.

On Monday, the District Locust Control Organisation of Eastern Africa Director-General Stephen Njoka said the aircraft conducting aerial spraying had been increased to six and that further spread of the pests is unlikely to occur.

Dr Njoka said both ground and aerial spraying is ongoing even as five surveillance choppers monitor the situation on the ground.

"The furthest the locusts have gone is Embu, but that is under control. It's very unlikely that they will get to the breadbasket," he said.

Fao's senior locusts forecasting officer Keith Cressman said more swarms are entering the country because they are being hatched in the adjacent areas of Eastern Ethiopia and Southern Somalia.

"The swarms will continue moving across the northern parts and into the central parts of the country," he said.

ERADICATION TIMELINE

Mr Cressman, who is coordinating satellite monitoring of the locusts in a centre in Rome, said breeding has already started in Marsabit, Mandera, Garissa, Isiolo, Wajir and Turkana.

"Just in the past week, some of the swarms started to copulate and soon they'll start laying eggs. Even though these areas have been sprayed, it is very difficult to find all the swarms once they have matured and start to fly about," he said.

Mr Cressman said Fao is working with the government to upscale aerial spraying, with two additional technical experts from the United Kingdom and Morocco set to join ground operations.

He said plans are in top gear to bring an additional five planes to help fortify control operations.

"The impact is minimal as the locusts found most of the crops being harvested, but the impact on livestock has been very high. Control measures must be buttressed before the upcoming planting season or else the country will suffer substantial losses," warned Jasper Mwesigwa, the regional food security analyst for Intergovernmental Authority on Development.

He said the earliest the pests would be eradicated is six months because the hoppers keep laying eggs and hatching.

Fao had earlier predicted that the pests will not get to the agricultural heartland of Rift Valley.

The organisation said the locusts would head northwest into Baringo and Turkana counties before entering Uganda.

But while agreeing with the Fao forecast, Dr George Ongamo, an entomologist at the University of Nairobi, warned the country against being complacent, reckoning that there "were more swarms in Eritrea, Djibouti, Somalia and Egypt" that could get into the country any time.

Fao had based its predictions on the Inter-Tropical Convergence Zone projections that indicated a shift in the wind patterns in Kenya.

The swarms that crossed into Kenya from Somalia and Ethiopia in December last year have spread to Mandera, Marsabit, Wajir, Garissa, Isiolo, Samburu, Meru, Embu, Baringo, Kitui and Laikipia.

The locusts -- a lethal species of the grasshopper family that eats every green matter in its sight -- have the potential to destroy seasons of food, prompting acute hunger and substantially slowing down the economy that is dependent on agriculture.

Aerial spraying of the pests began on Monday in Embu. On Saturday evening, aircraft conducting aerial sprays and personnel from the Ministry of Agriculture were dispatched to Mbeere South, where the insects are wreaking havoc on muguka (khat) farms.

Mbeere South Deputy County Commissioner Charles Igiha said the government is determined to ensure the locusts do not spread to other areas.

In the meantime, the insects crossed the Kitui border on Friday and landed in Mbeere, throwing residents into panic.

They first invaded Kiambere and Mutuobare villages then spread to Mariari and Mavuria, where the lucrative stimulant is grown in large scale.

Desperate farmers used pepper smoke in a bid to chase away the insects. On Monday, Kiambere MCA Lenny Mwaniki welcomed the government's quick response.

The pests have also spread to Tana River County, with locals in Bura Dhima village reporting that the insects have cleared vegetation covering kilometres.