Codling moth
Summary sheet Introduction Traps and trapping Fruit inspection Appendix 6. APB Infonote: Codling moth
Summary sheet Codling moth
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Codling moth (Cydia pomonella) is a major pest of apples and pears. It occurs worldwide (Appendix 1) where pome fruits are grown with the exception of Japan and Western Australia. If not controlled the codling moth caterpillar can infest 100% of the fruit crop. In eastern Australia, where codling moth is a serious pest, up to 10 broad spectrum sprays per season are required for satisfactory control. Unfortunately, these sprays kill beneficial insects and lead to problems with other pests such as light brown apple moth and phytophagous mites.
By maintaining freedom from codling moth, Western Australian apple and pear growers have a great advantage over other States and countries. To remain free of codling moth, vigilance is required by quarantine authorities, growers and the public.
All codling moth outbreaks in recent years have been found as a result of the caterpillar being found in apples at or near the centre of the original infestation. This is despite pheromone traps being set. In the past, there has not been a systematic trapping or other type of surveillance in high-risk areas. Thus incursions have not been detected early and eradication cost has been high.
An effective surveillance system consisting of timely trapping for adult moths and regular fruit inspection has been implemented. Growers, orchard fruit thinners, packing shed fruit handlers, wholesalers, retailers and the public must be made aware of codling moth and what to look for. Extension materials (Appendix 6) should be distributed to industry workers at every opportunity.
Traps
The most effective trapping device found by experiment is the BiolureÒ Winged Trap (Appendix 2). This sticky cardboard trap has a controlled release pheromone lure placed on the inside that attracts the adult male moth. The male (and female) moths are mainly active during the period from October to April. It is during this period that the traps should be placed in bearing apple or pear trees.
Appendix 3 shows how to assembly the trap. The lure is contained in a sachet and should be stored in a refrigerator. Unopened, the lure has a short shelf life. Unused lures should be replaced every year. Once the lure has been removed from the sachet it should be handled by tweezers and put directly on to the inside of the trap making sure that it does not touch hands or any other part of the trap. If contamination occurs, the moths may be drawn to the outside of the trap and not be captured.
The lure is effective for two months in the field, with the trap and pheromone being replaced at the same time. Traps are first installed on 1 October and should be replaced on 1 December and 1 February.
All traps should be removed and returned to the nearest agency office or the Surveillance Unit for destruction. The traps should not be left on the properties on the trees or anywhere on the premises as they may get confused with new traps or divert codling moths away from the new traps. The Pest Surveillance Unit will supply replacement traps.
The codling moth trap should be hung about head height within the canopy of the tree making sure that it is clear of leaves and branches (Appendix 2). Ideal trap placement within an orchard is about one row in from the edge preferably adjacent to an open space such as a field or pasture. Adults tend to migrate outwards as they spread towards the boundaries of the orchard but are reluctant to venture beyond this if there is nothing to attract them. Hence, there may be a build up of the population of moths near the edges of the orchard.
Metropolitan area
Sentinel trapping only - on properties with fruit fly trap. Place in apple trees.
Commercial Orchards
For Perth Hills Districts, Bridgetown, Manjimup, Donnybrook, Dwellingup and other south west commercial apple growing areas, place (to be advised) traps per hectare of orchard. Farmers should be encouraged to inspect traps where possible with regular visits by agency staff for the renewal and servicing of the traps.
Neglected orchards
Neglected orchards have a history of severe codling moth infestations and are a source of concern. Owners are being encouraged to remove their redundant trees. Until they are removed, the agency and landowners should place codling moth traps at (to be advised) traps per hectare of orchard. Fruit inspections should also be conducted at the appropriate times.
Packing sheds
1-2 traps should be placed in pome fruit trees near packing sheds in major apple growing areas between November and May. Servicing should be undertaken by agency or staff if practicable.
- Set traps from 1 October until 1 April.
- Examine for moths every week. If dusty and ineffective, renew when necessary.
- Renew lures every two months, 1 December and 1 February.
- Obtain replacement traps from the Invertebrate Pest Monitoring Unit.
For the early detection of codling moth in Western Australia, growers must become involved in trapping and inspecting fruit on their orchard.
Trapping in commercial and neglected orchards
Once the traps have been put out on the property, growers need to inspect them once per week. The Trap Information Sheet (Appendix 4) must be filled in with the recorded date of inspection of each trap. At the end of the season the completed form(s) should be sent to the address on the top of the form.
Trapping on hobby farms and backyards
Owners of hobby farms and backyard orchardists can be supplied with traps on request in certain areas prone to new infestations. Requirements for the servicing and renewal of the traps and recording results are the same as for commercial growers.
If any suspect codling moth is caught it must not be removed as the moths are very fragile. The entire trap should be sent undisturbed in a suitable container to:
- The nearest Agriculture Western Australia Regional Office
- Or send to:
Richard Johnston
Invertebrate Pest Monitoring Unit (IPMU)
Agriculture Western Australia
3 Baron Hay Court, South Perth.
Telephone (08) 9368 3583
- Notify IPMU of dispatch
Trap locations, servicing dates, replacements and results must be detailed in the forms provided (Appendix 4). There is no value in the surveillance unless this is done. The completed original copies should be kept at the Regional office and the duplicate faxed or posted to Mr. Johnston, IPMU, South Perth. If the trap location is changed this should be recorded on the form with the results.
While trapping is considered to be an effective method for detecting codling moth, there is a limit to the number of traps that can be allocated and serviced. In optimal conditions the traps attract male adult moths from a distance of 500 metres down wind. Examination of fruit for signs of codling moth damage compliments the trapping program.
Damage to apples is evident in spring when the first generation of moths are developing. The caterpillars begin emerging when the small fruit are 2.5-3 cm in diameter. Damage is seen as frass (excrement looking like sawdust) at the exit and entrance holes. Infested fruit are usually in tight clusters and may are removed when thinning. A search at this time for a small population is usually difficult and time consuming.
The second generation of caterpillars becomes evident during mid-January to mid-March. At that time the apples are larger and the emergence frass and exit holes are easier to see. Damaged fruit usually ripens prematurely and may drop to the ground. It is at this time that the grower or operator is more likely to find the moth.
Although codling moth seem to prefer red to green apples, damage is easier to spot in Granny Smith and other green apples. However, prematurely ripening red apples on the tree and on the ground should also need to be examined.
Inspection of fruit is not only the grower's and the agency's responsibility. Orchard fruit thinning and picking staff, packing shed staff, wholesalers, retailers and the public must be made aware of codling moth at all times especially at pre and post harvest where apples, pears and other susceptible fruits are handled.
Past incursions of codling moth have been detected by finding infested apples. Perhaps if more traps are used, earlier detection may be achieved but traps should never be fully relied on to pick up the moth before it is found in the fruit.
Instructions for pome fruit growers
While the orchardist has to be vigilant at all times for codling moth, there are specific times the intensity of inspection needs to be increased. The ideal time for a systematic search is during the period when fruit is becoming ripe and during fruit picking, when the second generation of caterpillars will be maturing resulting in more obvious damage and frass. Apple and pear inspections on hobby farms, backyards and neglected orchards should also be done.
What to look for:
Orchard situations
1. Premature ripening of individual apples
Fruits infested with codling moth caterpillars tend to ripen prematurely. This can be seen on red fruit by its deeper colour and on the hard green fruit by a lightening of the green. Even if there is no obvious surface frass or exit or entrance holes (Appendix 6) this fruit is worth cutting open as there may be immature larvae or entrance through an open calyx or wound. This is especially true of the Delicious variety. Red apples are more commonly infested but Granny Smith and other green varieties are easier to see.
2. Fruit on the ground
Codling moth infested fruit also falls on the ground and while the fruit on the tree should be inspected windfalls are worth an examination.
3. Tree location
Trees near the perimeter of the orchard may be more heavily infested than trees in the centre of the orchard. Codling moth adults spread out slowly but usually halt near the edge of the orchard when faced with open paddocks or a barrier of native bush or trees. Consequently there may be a greater infestation in the edge rows of the orchard. The orchardist should concentrate his efforts in these areas4. Vigilance at harvest
During harvest, fruit pickers need to be shown illustrations of codling moth damage and be asked to look out for frass and other outward signs on the fruit. Any reject and suspect apples should be put aside. This is one of the more effective ways of detecting early infestations.
Packing sheds
All damaged apples and pears are usually rejected during grading. All rejects should be kept in a separate bin and inspected when grading is finished. Posters depicting codling moth damage should be displayed in all packing sheds.
Wholesale and retail outlets
Posters and APB infonotes showing codling moth should be distributed to agents and retailers for display on their premises. This would encourage the public to report any findings in the fruit and report it to the agency.
If a suspect infested apple, pear or other fruit is found it should be put into a sealed cardboard box or carton and sent by courier to:
Richard Johnston
Invertebrate Pest Monitoring Unit (IPMU)
Agriculture Western Australia
3 Baron Hay Court, South Perth.
Telephone (08) 9368 3583
Notify IPMU of dispatch
As with trapping, full details of inspections should be recorded. Fruit Inspection Data Sheets (Appendix 5) should be distributed to all involved in the trade. Sheets should be completed on a daily or weekly basis and kept at the inspectors office. A copy of all sheets should be sent or faxed to the IPMU at the end of the season in April.
Appendix 1 Codling moth distribution map
Appendix 2 Codling moth trap
Appendix 3 Wing trap assembly instructions
Appendix 4 Codling moth trap information sheet
TO: Richard Johnston Postal Address:
Invertebrate Pest Monitoring Unit Locked Bag 4
Entomology, South Perth Bentley Delivery Centre
Agriculture Western Australia SOUTH PERTH WA 6983
FAX: (08) 9367 2625
NAME
PROPERTY ADDRESS (not postal address)
PHONE NO.
DATE WHEN TRAP PUT OUT / /99
Trap ID |
Date |
Location of |
Fruit |
Suspect If yes see below |
Date trap |
Comments |
Contact IPMU immediately if suspect moth is found
Appendix 5 Fruit inspection data sheet
TO: Richard Johnston Postal Address:
Invertebrate Pest Surveillance Unit Locked Bag 4
Entomology, South Perth Bentley Delivery Centre
Agriculture Western Australia SOUTH PERTH WA 6983
FAX:(08) 9367 2625
NAME
PROPERTY ADDRESS (not postal address)
PHONE NO.
Date |
No. of trees |
Apple/pear |
Size of |
No. of |
No. |
Comments |
Person submitting sheet: Name Ph
