The invasive papaya mealybug (Paracoccus marginatus) has been confirmed in Townsville, posing a significant biosecurity concern and bringing the threat closer to Queensland’s primary papaya-growing regions.
Papaya mealybug is a sap-sucking insect that weakens plants by feeding on their sap, causing leaf yellowing, premature fruit drop, and stunted growth. It also excretes a sticky substance known as honeydew, encouraging the growth of sooty mould, which further reduces plant health and fruit marketability. Severe infestations can lead to significant crop losses.
Mealybug infested papaya tree in a backyard in the Darwin area (Source: Northern Territory Government)
The mealybug was detected on municipal frangipani trees in Townsville’s North Ward area. Queensland’s Department of Primary (DPI) have confirmed the pest through a molecular test.
“We are urging growers to closely monitor for the pest in major papaya-growing regions,” said Emily Pattison, Papaya Extension Officer with the DPI. “The pest is deemed ineradicable, meaning no trade restrictions will apply if detected on properties. However, early detection is critical to managing its spread into commercial growing areas.”
Frangipani trees appear to be a strong host for the pest, with most detections reported on this plant. “I’ve been inspecting frangipani trees weekly near Mareeba’s visitor centre to monitor for any signs of infestation,” Emily added.
Papaya mealybug on underside of a frangipani leaf (source: Queensland Government)
Papaya mealybugs are small (2–3mm), oval-shaped insects with a pale yellow body covered in a white, waxy coating. Infestations are often accompanied by clusters of fluffy white masses on leaves, stems, and fruit. If you suspect the presence of papaya mealybug, you can report it by contacting Biosecurity Queensland on 13 25 23 or via the DPI website.
The detection of papaya mealybug underscores the importance of maintaining strong biosecurity practices. Growers are advised to regularly inspect their crops, clean equipment, and avoid moving plant material between properties.
For more information on identifying and managing papaya mealybug, visit the DPI website (Papaya mealybug | Business Queensland) or contact Emily Pattison at 0491379771 or Emily.pattison@daf.qld.gov.au
