Biosecurity Update: Pyriform scale (Protopulvinaria pyriformis)

In May this year Pyriform scale (Protopulvinaria pyriformis) was discovered in the Perth metropolitan area. Later detections have been made on a variety of host plants in a number of surrounding suburban areas in Perth.

These detections are believed to be the first detection of this scale (and genus) in Australia.

Pyriform scale is a polyphagous soft scale, native to South America. In recent years it has become a major pest of bay trees in urban landscapes of Greece and Spain. Direct damage is caused by pyriform scales feeding on plant sap and affecting the plants’ nutrient uptake. Heavy infestations of pyriform scale on plants can result in reduced vigour, leaf drop and reduction in size and quality of fruit. Indirect damage is caused by the growth of black sooty mould on leaves. Sooty mould growth is encouraged by honeydew secreted by pyriform scales as they feed. Sooty mould covers leaves and fruit, blocking sunlight and minimising the energy available to the plant.

Pyriform scale has a wide host range of more than 100 species across 34 plant families. Hosts include a number of horticultural and ornamental plants such as mango, avocado, citrus, banana, guava, passionfruit, pomegranate, papaya, eucalyptus, hibiscus, gardenia, ivy, myrtle, laurels, paperplant and frangipani.

DEDJTR (DEPI) will be circulating an industry notice shortly to provide further information about the scale and will most likely be commencing surveillance in the next few weeks. Once present, plant pests can extend their range and impact areas that were previously thought to be clear. In the last year there were 25 reports of known plant pests that have extended their range.

Suspected plant pests that are new or have extended their range should be reported to the Exotic Plant Pest Hotline 1800 084 881.