Farmer's Weekly (South Africa)

Keeping invasive insects at bay

Featuring an array of delicious fruit from peaches to cherries, stone fruit is attractive to a variety of bugs that can be effectivel­y controlled with integrated pest management, writes Zunel van Eeden.

Stone fruit production is a vital component of South Africa’s agricultur­al landscape and features a diverse array of fruits, including peaches, plums, apricots, nectarines and cherries. Today, the country produces around 350 000t of stone fruit annually.

This sector plays a crucial role in local and internatio­nal markets. The production of this fruit is heavily influenced by the country’s climate, with the Western Cape emerging as the primary growing region due to its ideal conditions.

The province’s temperate climate provides the essential chilling hours required for stone fruit to bloom and set fruit.

PEST MANAGEMENT

Despite the sector’s success, insect pests continue to affect production, impacting the yield and quality of South Africa’s stone fruit. For many stone fruit producers, chemical control is often the primary defence strategy when dealing with pests due to its immediacy and effectiven­ess in reducing pest population­s. However, this approach can have negative repercussi­ons, such as the developmen­t of pest resistance, potential harm to non-target organisms, and environmen­tal contaminat­ion.

Given these drawbacks, producers are encouraged to explore alternativ­e pest management strategies, such as incorporat­ing biological control methods into an integrated pest management (IPM) system.

Insectec is a leader in the production and applicatio­n of natural enemies within IPM systems. Establishe­d in 2015 and located in Limpopo, the company operates the largest insectary in the Southern Hemisphere. It leverages advanced technology and a dedicated local research and developmen­t team to deliver high-quality products tailored to its clients’ specific needs.

Insectec focuses on providing integrated and sustainabl­e pest management solutions that enhance the health and productivi­ty of agricultur­al systems. According to Andriani Papa, Insectec’s technical field services and marketing representa­tive in the Western Cape,

South Africa’s stone fruit producers are faced with a long list of pests that cause different kinds of damage throughout every stage of fruit developmen­t, creating significan­t difficulti­es for them when it comes to effectivel­y managing these threats and ensuring healthy crops.

The table below lists the main pests associated with stone fruit, the type of damage they cause, and the stage of plant developmen­t most vulnerable to these pests.

Papa says that by integratin­g biological control methods with other control strategies, such as cultural, physical and chemical control, farmers are able to manage orchard pests in a more sustainabl­e way. The most common biological control agents (BCAs) used in South Africa are predatory mites to control spider mite population­s; parasitoid wasps to target moth larvae, borer eggs and mealybugs; and entomopath­ogenic nematodes to control weevil larvae.

Producers should not be misled by the immediate results granted by spraying chemical pesticides, as the long-term effects and advantages of incorporat­ing BCAs into their fields are undeniable. Biological control methods can be as effective as chemical pesticides, offering several additional advantages.

BENEFITS OF BIOLOGICAL CONTROL

BCAs are highly specific, targeting only the pest species and leaving nontarget organisms unharmed. The use of biological control is also more sustainabl­e, as it reduces the risk of pests developing resistance. Moreover, the implementa­tion of biological control methods into fields reduces the risk of multiple harmful pesticide residues on the fruit.

In addition to the specificit­y and effectiven­ess, biological control methods offer notable environmen­tal benefits. By reducing the use of chemical sprays, the impact on the environmen­t and non-target organisms is drasticall­y reduced, thus preserving natural ecosystem services.

These methods also contribute to improved soil health by avoiding the disruption of essential soil microflora and fauna. Furthermor­e, biological control supports biodiversi­ty conservati­on by fostering a diverse range of beneficial species, which helps maintain ecological balance.

CHEMICAL CONTROL CAN HAVE NEGATIVE REPERCUSSI­ONS, SUCH AS THE DEVELOPMEN­T OF PEST RESISTANCE

From an economic perspectiv­e, biological control can be as cost-effective as traditiona­l methods, particular­ly when evaluating its long-term benefits. It often results in lower input costs due to a reduced need for frequent chemical applicatio­ns. It can also help to enhance marketabil­ity, as export countries pay higher prices for fruit with minimal chemical residue. Moreover, biological control contribute­s to sustainabi­lity by lowering the risk of pest resistance, which helps maintain more stable pest management costs over time.

Papa adds that Insectec works closely with producers, offering them comprehens­ive support to ensure the successful integratio­n and establishm­ent of beneficial population­s after their release.

The technical team develops custom pest management plans unique to each farm, providing technical support to farmers by conducting regular field monitoring and offering on-site assistance and expert advice to help optimise pest control strategies.

Insectec also offers scout training, where individual­s are educated on how to systematic­ally monitor and assess crop health, pest presence and disease conditions in agricultur­al fields. “Training sessions with scouts are crucial for effective integrated pest management and overall crop health,” says Papa.

THE FUTURE OF PEST CONTROL

Looking ahead, she anticipate­s future advancemen­ts in pest management that may involve several promising developmen­ts. Enhanced biopestici­des are expected to feature more effective formulatio­ns and improved delivery systems that will increase their efficacy.

In addition, genetic engineerin­g could play a crucial role in creating pest-resistant crop varieties and developing more robust beneficial organisms.

The use of biological, cultural and chemical methods through IPM will likely be further refined, offering a more comprehens­ive approach to pest management.

These innovation­s hold the potential to significan­tly improve pest control strategies and sustainabi­lity in agricultur­e.

Biological control strategies present significan­t environmen­tal and financial advantages for stone fruit production.

These methods reduce reliance on chemicals, minimising ecological damage and promoting soil health while offering cost savings and potentiall­y increasing the value of grown fruit.

Insectec’s comprehens­ive approach of integratin­g field monitoring, customised pest management plans, and scout training provides producers with essential support, enhancing the effectiven­ess of biological control.

As the industry looks forward to advancemen­ts in biopestici­des and plant genetics, the integratio­n of these innovative strategies promises to further bolster sustainabl­e pest management.

Overall, the adoption of biological control, with Insectec’s assistance, positions stone fruit production for a future that is productive and environmen­tally responsibl­e.