Exirel is a forage brassica insecticide for control of diamond back moth, white butterfly, leaf miner and aphids.
FMC NZ southern area business manager Stan McKay says the company’s tech support

sessions are all about improving insect pest management programmes using IPM effectively.

“The term IPM is being used more frequently when considering insect pest control in forage brassicas but the meaning is often not very well understood.”
Distributors attending infield training events learn more about identifying both beneficialand pest species in their local crops to

increase their knowledge and pass on the value of IPM.

IPM stands for integrated pest management, or the the use of three pest control methods together in a compatible way, McKay says.

THE THREE METHODS ARE:

1. Biological control - the use of beneficial insects that naturally occur in the crop and making sure they are not disrupted by using pesticides that may impact the beneficial species’ various life cycles. Parasitic wasps and hoverfly larvae are two important examples

2. Cultural control - any farm management technique that disrupts the pests and enhances the beneficial population. Examples may be the variety of crop selected and its insect tolerance, timing of planting, weed control along fence lines or the use of irrigation.

3. Chemical control - IPM is not about eliminating all pesticides but rather using them in an effective way that minimises disruption to beneficial species. It is important to understand the impact each product has on every beneficial species at each of their life stages. In the example of the hoverfly, it is the larvae not the adult that preys on aphids. The mixing of insecticide active ingredients can also have a negative impact on the beneficial species through the mixture causing greater disruption

than either of the ingredients used on their own. For the target pests a mixture can increase the risk of pesticide resistance.

McKay says to avoid disruption to beneficial species in clients’ crops, key points include:

• Understand the pest and beneficial species present at each crop stage, have a plan from establishment through to late crop

stages.

• Use broad spectrum insecticides at the establishment stage of the crop, leaving Group 28 insecticides (Exirel) for mid to

later stages of the crop when beneficial species are present.

• While there are many selective insecticides available, that does not mean they are safe to all beneficial species. Gather data on each product used and its impact on beneficial species.

• Use a hand lens to monitor the crops and identify the eggs of both pest and beneficial species along with early juvenile stages to help plan treatment application timing.

• Once the crop is established apply Exirel early at the first sign of pest pressure to minimise impact on yield and spread of insect transmitted disease, at the same time establishing beneficial populations.

• Continue to monitor the crop for signs of beneficial activity such as mummified aphids and parasitised caterpillars along

with overall reduction in pest population. Retained biological control continues after Exirel control has subsided.

For advice on implementing an IPM approach enhanced with Exirel insecticide for your clients, contact your local FMC NZ area business manager.