With most of insect pests having developed resistant to majority of insecticides, biological control is the best approach to control them entirely, if left to flourish. Unfortunately, Batswana crop farmers have limited to zero knowledge on appropriate insecticidal classes and the pests they control hence why the indiscriminate use of insecticides that are not only harmful to essential soil micro-organisms, but beneficial insects. Also, indiscriminate use of insecticides ultimately leads to the insect pests to develop resistant and resurgence which renders the insecticides ineffective. As you tend to your crops, you will notice insect diversity, which is the presence of good and bad bugs. Good bugs fall in three categories which are predatory bugs, parasitoids and pollinators. These are fundamental beneficial insects for maintaining a healthy crop ecosystem. Predatory bugs as the name suggests, prey on insect pests and eliminate by eating them. Examples are ladybird beetles which feed on aphids, preying mantids feed on most larvae, predatory wasps such as mud daubers (moruthwane) and green lacewing larvae which feed on fall armyworm larvae. Other arthropods that are predatory in nature are spiders, centipedes, scorpions and ground beetles. Parasitoids prey on their hosts by laying eggs on or in the ‘bad bugs’ of which upon hatching, the larvae feed on the host insects from inside out resulting in the death of ‘bad bugs’. Parasitic wasps and several family of flies belong to this category. Examples are Ichneumonids, Braconids, Cortesia and Trichgramma species. Pollinators include the different families of bees, butterflies, moths and adult flies. We depend on as pollination encourages fruit production and crop diversity.
For us to attract good bugs in our farms, we should provide necessities such as proper habitat, food and water to make them thrive. Food sources for pollinators can be nectar and/ pollen producing flowers, shrubs and trees (both indigenous and exotic). For example, African marigold flower, wild aloes, acacia trees and Mosetlha tree just to mention a few. It is also important to provide clean water sources for beneficial insects as all living beings require water and food to function. Beneficial insects normally have three different types of habitat for them to complete their lifecycle. These habitat types are nesting areas, overwintering sites and forage sites. These sites are usually provided through mulch, native shrubs/ trees and zero-tillage farming. However, with ever increasing demand for land, these habitats are destroyed hence reduction in insect diversity. Consider planting hedges, buffer zones, or interspersed rows with native wildflowers and shrubs for beneficial insects to forage. Even a small patch of native wildflowers that continues to bloom throughout the seasons will draw in all types of these native flowers could make a huge difference in the abundance of good bugs. Other horticultural crops like broccoli, coriander, cowpeas, fennel and carrots are few of which attract good insects to your farm.
Beneficial insects hold a reputation of being ‘friends of farmers’ as it is nature’s way of keeping insect pests in check through biological control as they are readily available and it is a tool for farmers to save money in pest control. Other African countries such as Kenya, South-Africa and Ghana are exploiting the use of beneficial insects as much of their crop produce is exported to the EU market which has strict legislation on chemical residues. With our growing agricultural industry, we can preserve these beneficial insects at a small scale as currently and in the future, they’ll remain as the best option in pest control.
