November 2023 pest of the month: Aphids

17 November 2023

Aphids are small, bulbous, soft-bodied sap sucking insects that damage a wide range of plants, from beans to tomatoes. Aphids can harm plants directly through feeding and indirectly by injecting secretions that deform the plant. They also produce honeydew, fostering black sooty mould growth that renders plants unsaleable. Leaves may become stunted, chlorotic, fall prematurely or wilt. Even a small number of aphids can cause significant damage, while a large number can significantly reduce growth rates.

It is crucial to actively monitor aphids because small numbers can easily go undetected and allow populations to grow, increasing damage.

Cultural practices to reduce aphid populations include:

• managing weeds
• removing or pruning heavily infested stock
• monitoring incoming stock
• using protected cropping structures with UV-absorbing materials
• opting for resistant varieties, where possible.

Several biological control agents are commercially available, as well as many low-risk pesticides that are gentle on predators.

If you experience an aphid outbreak and need an identification, you can send specimens to Grow Help Australia (https://www.business.qld.gov.au/industries/farms-fishing-forestry/agriculture/crops/test/grow-help-australia/tests). Each year, all production nurseries receive six free pest or disease diagnostic samples.

For more information on aphids:

• see the aphid management plan at https://nurseryproductionfms.com.au/download/ipm-management-plan-aphids
• visit the Pest ID tool at https://pestid.com.au/login
• visit Biological Services at https://www.biologicalservices.com.au
• visit Bugs for Bugsat  https://bugsforbugs.com.au

For current production nursery minor use permits search ‘aphid’ at the top of the table at https://nurseryproductionfms.com.au/apps-mup-search