PaDIL

PaDIL is an image based website designed to create a 'virtual reference collection of pests and diseases'. Ken Walker tells us more about PaDIL and how it is used to identify a range of pests and diseases. 

The economic viability of Australia's plant industries is directly threatened by endemic and exotic plant pests and diseases. They impact on trade, market access, market development and, ultimately, the profitability and sustainability of Australia's plant industries.

Guarding against pest and disease invasion is a key component of Australia's National Plant Health Strategy and the rapid recognition of Emergency Plant Pests (EPP) is critical to ensure appropriate response strategies are implemented. PaDIL is a new tool that can greatly enhance this process.

PaDIL is an image based website designed to create a 'virtual reference collection of pests and diseases'. The primary aims of the website are twofold:

1. to significantly improve the rapid recognition of pests and diseases that are of concern to plant health in Australia, and
2. to broaden the base of people who can assist with the recognition of these pests.

The use of images, as well as common and scientific names, means that a wide range of people involved in plant health from farmers and importers/exporters through to inspectors and scientists can be involved in recognising pests and diseases. The web user can query for an individual species (eg. eucalyptus rust) or an entire group of species (eg. Phoracantha wood boring beetles) or a mixed assemblage of species (eg. Tramp ants) or hosts (eg. broad ' grains; specific ' sugarcane) or world and local bioregions.

The authors of PaDIL web pages are themselves scientists involved with Australian quarantine and biosecurity in Museums, Herbaria, Universities, CSIRO and several State Departments of Primary Industries. For each species on PaDIL, the author reviews the available scientific literature then image captured the diagnostic characteristics that best assist with the recognition of the pest or disease. In addition, full body dorsal and lateral images of the pests and disease symptoms are included.

One of the most significant hurdles to the rapid recognition of exotic pests and diseases is the lack of exotic reference material of pests and diseases in Australian collections. For exotic pests, PaDIL authors borrow identified specimens from overseas institutions, complete the required diagnostic image capture and then return the specimens or in some case lodge material in Australian collections.

For exotic diseases not yet in Australia, image capture presents a special problem as the host symptoms of the disease are as diagnostically important as the live fruiting bodies. Australian quarantine regulations prohibit the importation of live diseases into Australia. So, the plant pathologists have used their international professional networks to recruit the assistance of 81 pathologists from 15 countries to provide them with images of live host symptoms and fruiting bodies for exotic disease entries on PaDIL.  The results are wonderfully informative web pages authored by Australian pathologists but supplemented with live disease and host symptom images from around the world.

In addition to the images, authors provide a description of each pest or disease and notes on its distribution and host preferences. They also include useful references and websites. The finished webpage provides the user with a wealth of colour images and information specific to the pest or disease.

The PaDIL software was developed to be an effective, yet simply, image Content Management System (CMS). It uses a 'decentralised' authorship model which allows authors anywhere around Australia to simply use a web browser to log into the password protected SQL database and then to upload images or text and to create or edit existing species entries. The 'centralised' data and image storage model means we store everything in one place which ensures the fastest possible returns of images and data to users of the website.

We have monitored the usage of PaDIL over the relatively short time it has been available (went live in late 2005) and the software has been modified to enhance changing usage patterns. Initially, when there were low number of species available, users concentrated on accessing individual species pages. However, with the 1100 plus species now available on PaDIL, users prefer to scroll through and compare images across groups of species. So, we enhanced the software to allow users to choose their species and diagnostic images and the software builds them a comparative image tailored to their choice.  Literally, this allows them to see how characters change through range of species. The table also tabulates the written descriptions as well as the hosts and distributions for the species they have chosen.

In summary PaDIL provides:

• query through navigation drop down boxes or Simple and Advanced query pages
• a web page for each pest and disease
• pest web pages containing full body and diagnostic character images
• disease web pages containing images of the live disease and symptoms of the disease
• montaged pest images providing full depth of field for images
• the ability to enlarge, pan and zoom on these montage images
• species pages including a description of the pest/disease, host and geographic ranges, as well as references and URLs of interest.

It offers users the ability to:

• search or browse by (common and scientific) name, Hosts or Bioregions
• select species and images to build Comparative Image Tables (an extensive array of predefined comparative image tables is also available)
• email any webpage from within PaDIL
• convert species web pages into a single page fact sheet.

PaDIL is an initiative of the Department of Agriculture, Fisheries and Forestry (in particular OCCPO) and Plant Health Australia (PHA) and supported by the CRC National Plant Biosecurity. Authors include scientists from the Western Australian Department of Agriculture and Food, Queensland University of Technology, Museum Victoria, CSIRO Entomology, Queensland Department of Primary Industries and Fisheries, Victorian Department of Primary Industries and Rural Solutions, South Australia.