Apple Fruit Moth, Argyresthia conjugella

Argyresthia conjugella, Apple fruit moth is an economic pest of apple. It is mainly distributed in temperate climactic zones. The main host of this species is apple. It is widely distributed in the apple producing zones of Europe. It appears in the early summer from May to June.

Pheromone Trap for Apple Fruit Moth, Argyresthia conjugella

Biology of Argyresthia conjugella

The apple fruit moth is 4 mm long and 13 mm between the wings. The head and the intermediate body are white-yellow, while the outer body and the wings are grey browna (Sara Furenhed,2006). It has a white-yellow band at the lower part of the wings. The eggs are very small, only 0.5 mm long and 0.3 mm wide and it has a rounded oval shape. The colour is yellow-grey. The larvae are light yellow when hatched. It has 6 eyes on each side of the head and two antennae. It goes through 3-4 juvenile instars before it reaches full size of 6-7 mm (Ahlberg, 1927).. The female oviposits in June/July on the unripe fruit of rowan or apple, shortly after petal fall (Kobro et.al. 2003). After approximately two weeks (Ahlberg, 1927) the larva hatches and it immediately eats its way into the fruit. The larva does not leave the fruit until August / September, when it lowers itself down in a silken thread. Depending on the climate, the apple fruit moth hibernates on the ground as a larva or a pupa, during a period of 6-8 months (Ahlberg, 1927).

Nature of Damage

The larva of the apple fruit moth makes tunnels in the apple, in search for the seeds (Sara Furenhed, 2006). The apples get a bitter taste and rot in advance. Sometimes the larva pupates in the cavity with the seeds, but generally the moth leaves the fruit for pupation (Sara Furenhed, 2006). The apple fruit moth can reproduce well in apples, and it means that an orchard with a lot of fruit left on the orchard floor can contribute to the pest population the year after (Kobro, 1995).

Pheromone application guidelines

The following notes are guidelines of general nature and meant to give the user a head start in implementing pheromone monitoring programme. Local conditions and practices can very and can lead to customisation of the programme. 

Trap selection

The Deltra trap  is most sensitive trap to use for monitoring this insect. However, Moth catcher  may be used in dusty condition or in high moth population density. Do not re-use the trap to monitor different insects as this may lead to mixed catches.

Trap density

Two traps per hectare (2trap/ha) for small holdings and in field of uneven topography. One trap for every two hectares of large scale fields of homogenous lands.

Trap position

Near the highest point of the plant using supporting posts approximately 1 meter high or higher if the crop is higher.

Trap data and interpretation

Collect date weekly from the start of the flight of the over wintering generation.. During the height of the population more frequent reading may be needed. Decisions on pesticide application should not be taken solely on the trap catch data. Climatic and biological considerations should be taken in account. 

Lures

Lures can be changed every 4-6 weeks to get the most accurate results.

Lures handling 

Pheromone lures are very sensitive tool. They can be affected by exposure to elevated heat and direct sunshine. Direct touching by hand may cause cross contamination leading to mixed catches in the trap. Some contaminants such as Nicotine may have repellent effect reducing trap catch.

Lure Storage

Cool dry place. Shelf life can very from 3-36 months depending on the storage temperature.  See Technical Data Sheet for further details.