Using beneficial insects to outwit, outplay and outlast the pests

Using beneficial insects to outwit, outplay and outlast the pests

An Australian researcher has developed alternative pest control tools making a difference at home and abroad.

“To develop an effective and successful integrated pest management (IPM) program, one needs to ‘think like an insect’ to outwit, outplay and outlast the pests.”

So says Dr Robert Mensah, an Australian originally from Ghana who has transformed the way pests are managed in cotton and vegetable crops in Australia and parts of Africa, through his work on biologically friendly pesticides.

Dr Mensah is inspired by what he calls ‘conservational biocontrol’ which uses beneficial insects as a platform to support IPM in crops like cotton and vegetables.

Transforming the system

“When I joined the Australian Cotton Research Institute (ACRI) at Narrabri in 1992, cotton growers were applying more than 15 insecticide sprays to cotton crops to control insect pests.

“Now they hardly spray their crops as they have a range of biological tools, including Transgenic (BT) cotton and biologically friendly sprays that have almost eliminated the main pest Helicoverpa spp (boll and bud worms),” he said.

 Dr Mensah and Dr Amera in cotton field, Shelle Mella, Ethiopia. Photo: Atalo Belay, PAN-Ethiopia

Dr Mensah and Dr Amera in cotton field, Shelle Mella, Ethiopia. Photo: Atalo Belay, PAN-Ethiopia

Dr Mensah has spent 27 years as a researcher with the New South Wales Department of Primary Industries at the ACRI, most recently as Senior Principal Research Scientist and ACRI Director before his retirement in July 2019. During that time, he received many awards and accolades for his work, much of which has been supported by the Cotton Research and Development Corporation.

His research led to the development and commercialisation of environmentally friendly products including food sprays that attract beneficial insects and fungal biopesticides.

It’s estimated his research findings on cotton pest management and pesticide innovation has been adopted by 80 per cent of the cotton industry, saving the sector hundreds of millions of dollars and providing countless environmental gains.

Plant sucking pests such as green vegetable bug, green mirid, white flies, thrips and mites were now in Dr Mensah’s sights. The next technology he worked on was plant botanical product now commercialised by Innovate Ag Pty Ltd as Sero X®.

“When you use this type of spray, the pests are deterred from laying their eggs and feeding on the plants and more likely to be repelled by the smell and be directly killed if they feed on it,” he explained.

Helping African farmers

Thirteen years ago, Robert started working with the Pesticides Action Network UK to develop an alternative pest control tool for smallholder cotton and more recently, vegetable farmers in Benin and Southern Ethiopia.

Building on his pioneering work in Australia, he set up field trials and experiments in farmers’ fields to develop a product that not only worked, but that farmers were comfortable using.

The result was a yeast, corn dough and sugar-based food spray, made using cheap and locally available ingredients, enhancing populations of beneficial insects to keep pests under control.

 Beninese farmers have been trained in the food spray technique to attract beneficial insects ate achieving higher yields and incomes

Beninese farmers have been trained in the food spray technique to attract beneficial insects ate achieving higher yields and incomes

“These beneficial insects include ladybirds, green and brown lacewings, the predatory shield bugs, hoverflies and the aptly named assassin bug,” he explained.

The results have been impressive, with farmers trained in the food spray technique achieving higher yields and incomes.

Most recently the farmers have been using a light trapping system called the Zappa trap to monitor and manage moths and sucking pests.

“In this way, farmers can work with nature to keep pest levels low and use pesticides only as a last resort,” Robert said.

Author: Mandy Gyles, Plant Health Australia, [email protected]