Integrated Pest Management (IPM) incorporates the principle of biological control with selective use of chemicals. The ancient Egyptians were probably the first to employ biocontrol when they observed that cats fed on rodents which damaged their crops. This most likely led to the domestication of the house cat. The first record of biological control on citrus is recorded around 300 AD in China, where farmers set up colonies of native predatory ants in their orchards to protect the fruit from ‘worms’. By 1000 AD, date farmers in Yemen where employing a similar technique. In the 1860’s the Californian citrus industry was under severe threat from a devastating pest imported from Australia, cottony cushion scale (Icerya purchasi). The industry was saved from ruin by the timely importation of a natural predator, the vidalia beetle (Rhodalia cardinalis). Shortly after introduction of this predator, cottony cushion scale was reduced to a low status pest.

The first record of insecticide use is by the Sumerians who, around 2500 BC, were using sulphur type compounds to control insects and mites. After WW II, and with the advent of the Green Revolution chemical use became an integral part of modern agricultural practices. However, as early as the 1950’s, it was becoming clear that the widespread use of chemicals was inducing an ecological backlash with resurgence of pests, replacement of pest complexes with others and resistance to pesticides. The term Integrated Pest Management (IPM) was adopted and formalised during 1969 in the USA and many of the world’s governments adopted IPM as policy shortly thereafter.

Simply described, IPM is a management technique that employs the intelligent use of chemicals within a biological system. For example, in the fruit industry a spray programme can be designed to provide the maximum protection possible for a naturally occurring mix of beneficial insects in the environment while at the same time giving the farmer economic control of pests. IPM is, of course, applicable to other agricultural systems besides horticulture. Biocontrol, on the other hand, does not make use of chemicals but relies solely on the action of natural enemies of crop pests.

At Du Roi IPM we breed parasitic wasps and predatory ladybird beetles, better known as Biological Control Agents (BCA’s). These BCA’s are bred primarily for the control of certain Mealybug species and Red Scale. The insects are used by farmers in the horticultural industry as part of their pest control strategy to supplement naturally occurring beneficial insects. Depending on the pest situation (species composition and degree of infestation) massive numbers of bred parasites and/or predators are released over a period of time. The timing and choice of chemicals to be used is carefully planned so as not to negatively impact on the beneficial insects released.

At the insectary (where we breed our insects), we continuously mass-rear millions of BCA’s so that they are ready for sale to farmers when they need them. Once farmers are ready to begin introducing them to orchards or greenhouses their order is placed with Du Roi IPM and within 24 hours the ‘goodbugs’ can, in most cases, be delivered to the farm.

The parasites and predators bred by Du Roi IPM are host specific. Although not indigenous to South Africa, they have been present for decades. This is true for many other parts of the world where they were introduced. Being host specific, means that the BCA will only attack insects that they were designed to predate or parasitise by nature and that we wish to control. If the pest insect is not present then they will simply die off. Thus, the BCA’s bred by Du Roi IPM are safe, posing no threat to the environment, people or animals.