One or more of the features that are needed to show you the maps functionality are not available in the web browser that you are using.
Please consider upgrading your browser to the latest version or installing a new browser.
More information about modern web browsers can be found at http://browsehappy.com/
The larvae of this sawfly mine inside the leaves of the host plant. The structure of the lower leaf surface remains intact but the upper leaf cells are eaten, leaving just a thin, papery cuticle covering the mine. Individual mines may be 500 mm² in area and several mines may coalesce, destroying much of the leaf. Affected leaves have a brown 'blistered' appearance and may be shed prematurely. Damage is most common on foliage up to 3 m above the ground and small trees can be totally defoliated. In sheltered areas, the damage to large trees can extend high into the canopy (Kay, 1986). At a distance, heavily infested trees look like they have herbicide-spray damage.
In nurseries, or for the protection of ornamentals, a foliar spray of insecticide can be used to control the larvae but because some of the sprays used are not very effective against eggs and pupae repeat applications are necessary (Kay, 1986).
Classic biological control using an introduced parasitoid has been very successful in New Zealand (Withers, 2001).
In south-eastern Australia heavy infestations of P. froggatti can cause substantial loss of photosynthetic area of the host and this can result in stunted growth or even the death of small trees. This damage is of most concern where large numbers of saplings exist in a confined area such as eucalypt plantations, ornamental eucalypts in parks and gardens and potted trees in outside nurseries (Thumlert and Austin, 1994). Thumlert and Austin (1994) also stated that P. froggatti is rated as one of the most important pests in eucalypt woodlots in south-eastern Australia.
In Western Australia, P. froggatti is considered to be one of the more serious insect pests in the Eucalyptus globulus plantation industry (Abbott, 1993; Loch and Floyd, 2001). Outbreaks are quite common in some areas in Western Australia.
Prior to the introduction of Bracon phylacteophagus into New Zealand, it was predicted that P. froggatti could severely damage commercially important species of Eucalyptus. Consequently this could have serious consequences for the establishment of eucalypt plantations, particularly for those in warm, dry areas that favour insect survival and where newly planted trees may already be under stress (Nuttall, 1985; Kay, 1986).