Timing can make the difference in orchard pest management

For decades, chemical spraying has been a key part of pest management in orchards. But with insecticide resistance increasing, export markets demanding tighter maximum residue limits (MRLs), and some broad-spectrum active ingredients facing ongoing regulatory review, growers have more reason than ever to broaden their approach.

"Growers and agronomists across Australia are increasingly concerned about the withdrawal of key insecticides over the coming months and years. This will place even greater pressure on the limited range of insecticides that remain available," Biological Services director and owner Lachlan Chilman said.

This is where integrated pest management (IPM) comes into its own.

Rather than waiting for pest numbers to build and then reaching for a spray, IPM focuses on understanding what is happening in the crop and responding early. It combines crop monitoring, cultural and hygiene practices, biological control, compatible pesticides and expert advice to create a more balanced and sustainable pest management program.

Get ahead of the pest

Timing is particularly important when using beneficial insects and mites.

Introducing beneficials before pest populations reach damaging levels can give them time to establish and provide control when it is most needed. Waiting until an outbreak is well established can make biological control considerably more difficult.

That means IPM is not a set-and-forget strategy. Pest and beneficial populations need to be monitored throughout the season, with release timing and rates adjusted according to pest lifecycles, predator behaviour and changing conditions in the orchard.

With the right combination of biological control, pheromone disruption, trapping and compatible sprays, growers can build a program that responds to the crop rather than simply following a spray calendar.

A toolbox, not a single solution

The strength of IPM lies in using multiple tools together.

Beneficial insects, predatory mites and microbial products can provide ongoing biological pressure against pests, while selective chemical applications can be used when monitoring shows they are required.

This approach can also help protect naturally occurring beneficials and reduce the disruption caused by broad-spectrum sprays.

Technology is adding another dimension. Drones and automated release systems are making it increasingly practical to distribute beneficial insects across larger orchards, helping growers adopt biological control at commercial scale.

The benefits add up

Reducing unnecessary chemical applications can have benefits well beyond pest control. Fewer sprays can reduce labour, fuel and chemical costs, while also helping minimise disruption around harvest and withholding periods.

A more targeted program can reduce chemical exposure for workers, protect beneficial organisms and contribute to a healthier orchard environment.

BioResources was founded in 1996 by Richard Llewellyn.

Since that time BioResources has established itself as an innovative and reliable suppliers of insect egg parasitoids, notably MacTrix for macadamia nutborer and Anastatus for spotting bugs.

Fruit and nut growers across subtropical Australia know that spotting bugs, particularly Fruit-Spotting Bug (Amblypelta nitida) and Banana-Spotting Bug (Amblypelta lu tescens lutescens), can cause costly damage, but fewer know about the tiny native wasp working behind the scenes to suppress them. Anastatus continues to prove its value as an effective and adaptable biological control agent, offering Australian fruit and nut growers a sustainable alternative to chemical‑based management of spotting bugs.

As the pest management landscape continues to change, the message for growers is becoming increasingly clear: the best defence may not be another spray, but a better-timed and better-balanced strategy.

Image name: Anastatus inspecting Fruit Spotting Bug egg.jpg

Caption: Anastatus inspecting a fruit spotting bug egg. Image: Richard Llewellyn (Bioresources)