Light brown apple moth adults are highly sexually dimorphic and variable in wing pattern and colour, although a lighter, diamond-shaped area extending from behind the head to approximately one-third of the body length is typically visible at rest. Male forewing length ranges from 6-10 mm, compared with 7-13 mm in females (Thomas, 1975a). Males tend to have a higher contrast in colouration than females, although the level of contrast varies.
Pheromone traps have been widely used for detection and monitoring of populations of this species, since the identification of the sex pheromone (Bellas et al., 1983). A range of applications were reported by Suckling (1993), including insecticide resistance monitoring, insecticide spray reduction, and sample collection for population studies. Pheromone traps were proposed for use in the biosecurity detection of E. postvittana in the USA, in combination with codling moth lures, because there is no cross-talk between these species (Schwalbe and Maestro, 1988). This was apparently not adopted. Bradley et al. (1998) reported the use of traps with a spray threshold for insect growth regulator timing. Shoot tip assessment has also been used on apples [ Malus domestica ]and other crops. Suckling et al. (1998) used time searches for alternative host plants to study the host range. Egg sampling and pheromone trapping is conducted in Australian vineyards (Somers and Quirk, 2005). Trapping of females using fermenting port wine has also been used (Suckling et al., 1994).
Related invasive species
- Epiphyas postvittana
Related Farm Practice
- Rest
- Feeding
- Damage
E. postvittana is a small, bell-shaped moth, whose caterpillars feed on a very wide range of plants. The eggs, larvae and pupae can be associated with plant material and readily transported. The pest status of this insect in horticultural crops is very significant. It is native to Australia and was distributed to New Zealand, Hawaii, New Caledonia and the UK with apples [ Malus domestica ] or other plant material in the late 1800s. It has since spread throughout lowland New Zealand, and in recent years has spread through southern parts of the UK, and Ireland. In Hawaii, it appears to be confined to altitudes above 1100 m, and can largely be considered a pest of temperate regions.
Larval nests are typically seen as leaves webbed together, or attached to fruit. Fruit surface feeding is common within larval nest sites. On apples [ Malus domestica ], older skin damage has a cork-like appearance, and may be small (5 mm) or larger areas, depending on larval instar and feeding duration. Feeding sites on other fruits are similar.
Vectoring of Botrytis cinerea by larvae has been shown in grapes [ Vitis vinifera ], with up to 13% of berry damage (by weight) caused as a result (Bailey, 1997).
E. postvittana has a very wide host range, with 73 listed from Australia (Danthanarayana, 1975;Geier and Briese, 1981), and over 250 from New Zealand (Thomas, 1989;Dugdale and Crosby, 1995). Danthanarayana et al. (1995) have suggested that the better performance of E. postvittana on herbaceous rather than woody plants suggests that it primarily evolved as a feeder on the former. Mo et al. (2006) reported development of this species on Citrus spp.
In Australia, capeweed [ Phyla nodiflora or Arctotheca calendula ], curly dock [ Rumex crispus ] and plantain [ Plantago major ] are important hosts. In New Zealand, important perennial weed hosts are gorse (Ulex europeus) and broom (Cytisus scoparius), and in several regions it has been commonly recorded on annual weeds (Rumex obtusfolius and Plantago spp.), shelter and amenity trees (Salix spp. and Populus spp.) (Suckling et al., 1998). It has readily colonised the native Acacia koa (koa) in Hawaii, USA, along with gorse and other species, and there are also new host records from California, USA. The ecological host range in the existing geographic range has yet to be fully compiled, but it is clearly highly polyphagous.
Detoxification enzyme profile and expression of insecticide resistance is affected by larval host plant (Robertson et al., 1990), as is developmental rate (Danthanarayana, 1975;Tomkins et al., 1989). The larval and adult host plant preferences appear to be independent of each other (Foster and Howard, 1999). The molecular biology of the larval midgut, which can affect host range, has also been examined (e.g. Simpson et al., 2007).
A 1970s survey in New Zealand, conducted by DSIR Entomology Division Horticulture Group, in conjunction with horticultural advisors, returned the following results (Wearing, 2000):
- Exotic host plants: 88 (very common);78 (common);166 (occasional);332 (grand total).
- New Zealand native or endemic host plants: 3 (very common);16 (occasional);19 (grand total).
Larval development was not confirmed on all of the ‘occasional’ hosts.
The host plants recorded in the New Zealand survey were summarised by family (Wearing, 1999) and are included in the host list of this datasheet.