August Pest of the Month: Pyriform scale

Monday, 3 August 2020

Name: Pyriform scale (Protopulvinaria pyriformis)

First detected in Perth in 2015. This is the first case of a species of Protopulvinaria scale occurring in Australia. It is a serious threat to more than 100 species across 34 plant families. These include a number of important fruit crops and ornamental plants such as mango, avocado, citrus, banana, guava, passionfruit, pomegranate, papaya, eucalyptus, hibiscus, gardenia, ivy, myrtle, laurels, paperplant and frangipani.

Similar to:

Pyriform scales are similar in appearance to other soft scales in that adults secrete a clear, sugary liquid known as honeydew. Nymphs of P. pyriformis can look like citrus whitefly (Dialeurodes citri Ashmead) which is found on a similar host range.

Description:

Pyriform scales are mainly found feeding on the underside of the leaves, they have a pear-shaped body surrounded by a white waxy fringe, and have a protective coating that gives a raised scab-like appearance. Females can reproduce asexually and lay up to 300 eggs. Depending on host, two to several generations per year can occur.

Eggs: 

Are laid under the adult’s body and remain there until hatched.

Immatures:

Nymphs go through three development stages, all are mobile and look similar to adults. First stage nymphs are translucent green in colour. In later stages, body colour changes from translucent green to light green.

Adults: 

Are light brown to orange/pink with characteristic white fringing and can grown to 3mm.

Damage: 

Similar to damage done by other scale insects, adults secrete honeydew, which encourages the growth of sooty mould that interferes with photosynthesis. Heavy infestations can results in reduced vigour, leaf drop and reduced size and quality of fruit.

For further information please refer to the Pest ID Tool at: https://pestid.com.au/pest-insect/pryiform-scale 

Note that the Pest ID tool is now available with free access to industry.

An initiative of the Nursery Levy funded National Nursery Industry Biosecurity Program (NY15004) and ‘Building the resilience and on-farm biosecurity capacity of the Australian production nursery industry’ Project (NY15002).