You should monitor flies using fruit fly traps to understand general trends in the Qfly population, rather than measuring the population at a particular point in time. Even if you are monitoring regularly, it is still difficult to know exactly how many flies you are dealing with in the landscape, or predict what Qfly numbers will be in one season.
However, traps can indicate to you if Qfly arrives from outside the area, or about spring emergence.
Monitoring Qfly over time, across your defined area, will give you some really good information on how the fly behaves in your region, where to focus efforts, and enable you to assess the impact of your efforts over time.
Every area-wide management program should include a monitoring scheme. This includes checking traps regularly, as well as keeping records together with the geographical information about the catches/sightings.
You can then use the gathered data to:
- establish when and where Qfly cause problems
- generate risk maps
- monitor the effectiveness of any management actions
Here are some tips to making your monitoring more effective…
Choosing a trap type – In general, traps used for monitoring are traps targeting the male fly population, such as the Lynfield traps used for regulatory purposes. These are non-sticky, pot-type traps made of clear plastic. A lure is used to attract the Qfly to the trap (FT Cuelure). The trap contains a toxic substance so once the fly is inside the trap it dies and remains in the trap. Other trap types are available – some of them are female-biased (designed to attract females) that contain a protein attractant and can also include a toxic substance.
Placing traps – Traps should be placed within host tree canopies at a height of 1.5 – 2 metres (where the fly will be flying around). If you can, avoid areas that get very hot. It is important to place your traps before the fly becomes active in spring; you will most likely see Qfly activity from August. Remember that lures and toxicants need regular replacing (about every 3 months, so check the label).
Making a network of traps – The network of traps should cover the entire area under AWM. Some government trapping networks are already in place – check with your state department if this is the case.
Choosing locations within the landscape – To monitor Qfly populations over time, strategically placed traps are all that is required. For example, a 400-metre grid is often used in urban areas, with density decreasing as the landscapes change into rural areas.
Undertaking regular monitoring – Align your monitoring to fly activity. When there are more flies around, you should monitor weekly. Over winter flies generally slow down, so fortnightly monitoring is ok.
It is also important to be very clear about the purpose of trapping. There are a number of other ways in which traps are used and avoiding confusion is difficult.
For example, some growers are trialling high-density placement of female-biased traps for control (and some of these traps are also used as monitoring traps).
Growers are more familiar with trapping and may already know of the following trapping uses:
- to maintain or establish a pest free area (PFA) – a regulatory surveillance process. For information on regulated pest free areas contact the Department of Agriculture and Water Resources and watch this video made by the department about Australia’s fruit fly–free areas.
2. to meet domestic and international export protocol requirements, for some protocols with specific requirements (which may include trapping)
- Domestic – Interstate Certification Assurance protocols (ICAs) require that certain procedures have been undertaken before produce can be moved within Australia – please check with your state department for domestic quarantine and ICA information.
- International – International protocols may require that some form of trapping is undertaken; please check with the Department of Agriculture and Water Resources for current export information, or the Manual of Importing Country Requirements (MiCOR).