The project is just about to move from theory to practice, with a non-programmed hardware prototype hopefully ready in a weeks time. The final list of required parts has been compiled, with particular attention to reliability in outdoor conditions and useful battery life. An advanced regulator circuit has been specifically designed for the application and simulated in software, and some initial calculations put battery life anywhere between three to six weeks, which is pleasing given the amount of audio processing needed from the device; a more refined estimate won't be available until the software has been written and installed onto a finished device.
Other hardware work has gone well, although slightly slower than hoped for. There were some small delays in generating a suitable microphone and amplification solution - the unusual audible frequency requirements of the application (~15KHz) meant that most readily available hardware wouldn't work (consumer audio generally doesn't stretch that high because human hearing rolls off around there). Great care has also been taken to source affordable high-accuracy humidity and temperature sensors, and a photo-detector that would be able to work in direct outdoor light (most cheap ones are apparently designed for indoor use, for LCD monitors etc). All components are in stock and available from suppliers in large batches, and of course are affordable. The sensor hardware has been designed to work reliably over a length of cable up to 10 meters - the electrical aspect of this has been fully designed, but it's expected that some enclosures will be designed and 3D-printed for them in a week after all the electronics have been prototyped. On the software side of things, work on insect-recognition software continues in the office - it's hard to know how effective and/or difficult this part will be without a hardware prototype constructed, so updates on that will follow after hardware!
In short, an exciting time for the project. The next update should hopefully see some hardware fabricated!