Biosecurity for market access | June 2024
Visual inspection of fresh produce to check for signs of pests or disease can be a critical step for reducing biosecurity risks related to trade. Some pests, however, are difficult to detect visually.
What if we could dramatically improve our methods for detecting pests of quarantine concern at the border – or, better still, before produce is packed for market?
The key challenge – both at the border and in the pack house – is to be able to see, separate and respond to products that contain hidden pests with great reliability and efficiency.
Imaging technologies open promising new opportunities to do just that. For our third Biosecurity for market access update, we share our research to find innovative solutions to pest detection challenges.
Our researchers are developing near infrared (NIR) and X-ray imaging for automated, non-destructive detection of pests – harnessing technologies that are already commonly used at commercial pack houses, ports and airports.
New ways to see problem pests – before they are packed
Many commercial fresh produce pack houses use NIR optical scanning as a key component of their quality grading process. Our work to develop an NIR imaging system for pest detection that could be easily integrated with existing pack house scanning technologies is well advanced. This will enable pest-affected fruit to be automatically removed from the packing line.
To date, our work with NIR has focussed on detecting Queensland fruit fly and Mediterranean fruit fly in a wide variety of fruits. The sting marks made when fruit fly lay eggs into fruit – known as oviposition – can be difficult to detect using current visual inspection methods.
We have developed a prototype optical pest detection system and tested it through laboratory experiments. Our research shows that fruit fly damage exhibits unique characteristics that can be detected with NIR imaging. Our detection model identifies damage in fruit immediately after fruit fly oviposition with an accuracy rate of over 95%. With these exciting results and a patent secured, we will now commence commercial trials.
Optical pest detection prototype
Optical pest detection prototype
Finding pests at the port
Our early work with X-ray imaging also shows strong potential to augment existing border security systems. We have found that X-ray imaging can be used to non-destructively detect many internal pests in fruits, nuts and stored product with high accuracy – including Queensland fruit fly, Codling moth, Carob moth, dried fruit (Carpophilus) beetle, and mango seed weevil. Our trials indicate that high resolution 3D X-ray technologies may be particularly helpful to find very small or cryptic insect pests that are otherwise hard to detect.
X-ray imagery enables codling moth larvae to be seen in the lower left view of the apple.
By integrating artificial intelligence (AI) techniques, we seek to evolve our X-ray imaging methods into a real-time automated pest detection and quarantine system. As the volume of international trade grows, this technology may help biosecurity inspectors to rapidly identify high-risk consignments for more detailed investigation.
New lines of sight for researchers
The development of imaging technologies for non-destructive detection of insect pests also opens new opportunities for phytosanitary research. For example, NIR imaging could be used to accurately locate and count the number of oviposition sites on an individual fruit. This can provide an alternative method for estimating very low fruit infestation rates, or initial infestation rates in fruit being used in disinfestation studies. Similarly, X-ray technologies can provide a tool to non-destructively study the development and competitive feeding behaviour of pests within fruits and nuts.
Innovation through collaboration
Through these updates, we aim to connect with like-minded researchers, policy makers, industry members, ag-tech providers, and research organisations – towards enhancing the science, technology and regulation underpinning biosecure trade. So feel free to share this with others in your network.
We are interested to hear about your work in this field, or any feedback about our research. You can subscribe to these updates or contact our team at phytoriskscience@csiro.au