Don’t Kill These Pests

A centipede perched on a wooden log.. FILE
A centipede perched on a wooden log.. FILE PHOTO | NMG 

The invasion of the fall army worm into Kenya’s breadbasket last year did not only cause havoc to farmers, but also to gardeners across the country.

Unlike the true army worm, the fall army worms feed day and night, are most active during early morning hours and late evening, damaging plants in patches.

As is the case with most caterpillars, the juvenile fall army worms are small, meaning that feeding damage may largely go unnoticed in the beginning.

The fall army worm is an example of the non-beneficial pests. However, there are beneficial pests and these help eliminate and keep pest invasion at bay.

“For example, aside from centipedes feasting on soil-dwelling larvae, their movements aerate the soil allowing water and nutrients to reach the roots,” says Stanley Ndung’u of Brooklyn Plant Centre situated along Ngong Road.


He warns that while application of pesticides might seem like a good option, it could harm health of the soil and plants in the process. As such, Mr Ndung’u says it is wiser to opt for bio-friendly remedies that among other things include insects some of which are not harmful to humans and that we pay little attention to.

They include the ladybug/ ladybird, bumblebee, praying mantis, soldier bug, leafminer parasite and ground beetles.

Soldier bug

This highly mobile bug typically sucks out their victims’ juices by using their weapon-like proboscis.

It preys on some of the most potentially-damaging grubs, the fall army worm as well as soft-bodied insect pests including the corn borer, cabbage worm, flea beetles and potato beetles.

The veracious predator that varies in colour from brown to yellow also attacks the beet army worms, the cotton boll worm and the Mexican bean beetle.

Because the spined soldier bug preys on nearly 100 different pests, it’s highly effective in both gardens and greenhouses.


It is the subject of popular children’s books and a universal sign of good luck.

This bugs spend most of their adult and larvae stages lives feeding on all insect eggs they can find, soft bodies bugs and mites.

Mites are prolific breeders and are closely related to spiders. They are quite difficult to detect at the garden because of their tiny size.

Aside from reducing plant vigour, these little terrorists can transmit some dangerous viruses and disease. The adult ladybird eats mites, aphids and mealy-bugs. The hungry larvae version does even more damage to garden pests.

Ground beetles

These are hardly considered harmful to humans and while they bite, they rarely do so.

They are voracious predators of slugs, snails, cutworms, cabbage maggots, and other pests that live in the garden’s soil. You will occasionally spot them in outdoor settings feeding on insects. It is estimated that a single beetle larva has capacity to devour more than 50 caterpillars at any given time.


It is regarded as nature’s most industrious pollinator as it facilitates the fruiting of a number of vegetables and tree fruits.

They are different from the common honey bees. They are robust, large in girth, have more hairs on their body and are coloured with yellow, orange and black.

Unlike in honeybees, a bumblebee’s sting lacks barbs, meaning that the bee can sting repeatedly without injuring itself and by the same token, the sting is not left in the wound.

It goes without saying that the bumblebees help feed the world. This is because their movement results in greater yields of everything from tomatoes and peppers to strawberries and cherries.

Praying mantis

This beneficial insect derives its name from its two thick front legs lined with spikes for grasping prey.

In most cultures, the mantis is symbol of stillness. She can be said to be an ambassador from the animal kingdom giving testimony to the benefits of meditation, and calming our minds.

These non-aggressive carnivorous insects are interested in humans and as such pose no danger to anyone that comes in contact with them.

They are quick to strike and will eat just about any insect, bad and good, including wasps and bees.

Leafminer parasite

This is a small, black, non-stinging wasp that searches out leaf miners on which to lay its eggs.

Leafminers are the larval (maggot) stage of an insect family that feeds between the upper and lower surfaces of leaves. They are found in home gardens, greenhouses and landscaped areas.

The wasp kills the leaf miner as it lays its egg, and the emerging larvae use the dead miner as food.

While not usually threatening to plants, leafminer control is often necessary to manage the highly visible tunnels in leaves that can reduce crop value.