How communities, State can fight locust invasion menace

Plagues of locust have threatened agricultural production in Africa, Middle East and Asia for centuries. Desert locusts are potentially the most dangerous of the locust pest because of the ability of the swarms to fly rapidly across greater distances.

The last major desert locust upsurge in 2004 and 2005 caused significant crop losses in West Africa and had a negative impact on food security. Desert locusts are a major contributor to famine.

Locust reproduction is favoured by good rainfall and high temperatures. Global warming and flooding are among the many other results of climate change—hence the recent heavy rainfall in most places favoured the locust multiplication. Locusts lay their eggs when it rains and when these eggs hatch, a new swarm is born.

Locusts have their swarming phase; these insects are usually solitary but under certain circumstances they become abundant and change their behaviour and habits, becoming gregarious… this is what happened in Ethiopia and Somalia, forcing the insects to find their way into Kenya.

Due to a rise in temperatures in Kenya on account of global anthropogenic climate change, the desert locusts are finding the current weather conditions suitable for their existence.

Due to the flooding and adequate rainfall lately in the northern part of Kenya, today the area experiences luxuriant growth of vegetation – leading to plenty of food, which is attracting the locusts.

Since insects fly and can see far, while in Ethiopia and Somalia, they saw their food store in Kenya. This encouraged their migration, which might not stop if not countered. Already more counties within Kenya, such as Meru, Isiolo and Samburu, are beginning to see plagues of the locusts.

Now that the locust problem is with us, what should we do as a country? The government is using aerial spraying to kill and eradicate the locusts. This is not a very environment-friendly measure, but a necessary evil to keep in check the fast spreading and reproduction rates.

Environment-friendly methods could be the use of biological control or mechanical methods, such as having birds to feed on the locusts. This might, however, not be ideal or practicable now because we have low number of birds and they are not concentrated where the locust problem is already being experienced.

Local communities have been using drums, stones and smoke to expel the insects. They should be encouraged to continue, even though these methods are of low efficiency and if wholly relied on will lead to more destruction of the vegetation and grains in the affected areas.

Besides, the locusts will just move to neighbouring areas, and in the end, human populations will still suffer after crops and other vegetation is cleared by the busy locusts.

The desert locust has natural enemies such as predatory wasps and flies, predatory larvae, birds and reptiles. These may be effective in keeping solitary populations in check, but are of limited effect against gregarious desert locusts due to their enormous numbers in swarms and hopper bands.

The other method is the mechanical means of killing the locusts and burying hopper bands. This is a very labour intensive method and is difficult to undertake when large infestations are scattered over a wide area. They can also be scared away from their field by making noise, burning tyres or other methods.

Control measures

This, too, has a downside because it shifts the problem to neighbouring farms or counties and locusts can easily return to re-infest previously visited farms or counties.

Early warning and preventive control is the best strategy to adopt by locust affected countries in Africa and Asia to try and stop locust plagues from developing and spreading. As a country, let us use a combination of all the possible control measures to ensure the negative impacts of the locust invasion are eradicated or reduced to the bare minimum.

The national and county governments and all stakeholders should always be alert to early warnings and take the necessary preventive measures to check possible locust invasions in future. We need to be more proactive.  

Mr Munoru is a Project Officer at Pan African Climate Justice Alliance (PACJA), Nairobi. [email protected]