A swarm of locusts was on Monday spotted in Masinga, Machakos county.
Masinga deputy county commissioner John Ayienda confirmed the incident, adding the Machakos government has been alerted regarding the issue.
He said county agricultural officers have intervened and will use GPS to identify their exact location.
Ayando said agricultural extension officers had been directed to monitor the situation.
"The locusts came across from Kaburu to Kivaa and they are following the flow of Tana River," he said.
He urged locals to help eliminate them manually once they spot them as they wait for the national government to conduct aerial spraying.
Residents expressed concern their crops will be destroyed.
Musili Ngemeu, a farmer who alerted the authorities, called on the national government to act swiftly.
Last week, the destructive desert locusts invaded Kitui county, consuming livestock feeds.