- Administrative and agricultural officers, scouts, the public works department, railway workers and African labourers were deployed to combat the locust invasion.
- The government claimed financial constraints and stated that spraying locusts in African reserves would be harmful to Africans.
The earliest major locust invasion in colonial Kenya was in 1928.
First seen in February, they entered Kenya from Turkana and flew southwards along the Kerio Valley, stopping here and there to breed and feed.
They soon reached Uasin Gishu Plateau and Trans Nzoia, where they sojourned temporarily before proceeding on their southward journey into Tanzania.
They then made a northward and north-westward turn from Tanzania through Maasailand.
They also spread to other parts of the country such as Laikipia, Nyandarua and Voi.
The swarms left evidence of their work wherever they sojourned: dilapidated fields and hatched hoppers which caused further havoc, continuing well into 1929 and 1930.
The new wave of invasions in 1931 and 1932 were by the more voracious and destructive tropical migratory locusts.
Possessing a strong preference for graminaceous plants like millet, finger millet and maize, these locusts migrated from the upper reaches of River Niger and invaded Kenya from the direction of Uganda via Bungoma.
They moved southwards into Tanzania, before making a reverse flight towards the southern and western shores of Nyanza Gulf.
A large section of the swarms had moved across the Rift Valley towards Central Province and the Kenyan coast.
They devoured most of the plants and other vegetation, breeding and flying in huge swarms, usually covering a few miles wide.
The damage caused by the 1931 locust invasion was quite extensive. Available reports only cover the period up to June and the end of August 1931.
In the colonists areas, losses of maize and wheat were as follows: Nzoia Province (50 per cent), Nyanza Province (70 per cent), Rift Valley (25 per cent), and other areas 10 per cent.
African reserves made the following losses of grains including millet and maize: Bungoma, Kakamega and Busia (10 per cent), Kisumu, Siaya, Kano and Nyakach Central (15 per cent), Gusiiland and Luoland in southern Nyanza (50 per cent), Kericho (50 per cent), and Kikuyu (15 per cent).
These figures represented a money value of not less than £175,000 for maize alone.
Damage to wheat, sugarcane and small grain crops may be taken at not less than £75,000 (Sh9.9 million). Additionally, large quantities of grazing in all areas were destroyed.