Discrimination of Hover Fly Species and Sexes by Wing Interference Signals

Concerns about perceived widespread declines in insect numbers have led to recognition of a requirement for long-term monitoring of insect biodiversity. Here we examine whether an existing, radar-based, insect monitoring system developed for research on insect migration could be adapted to this role. The radar detects individual larger (greater than 10 mg) insects flying at heights of 150–2550 m and estimates their size and mass. It operates automatically and almost continuously through both day and night. Accumulation of data over a ‘half-month’ (approx. 15 days) averages out weather effects and broadens the source area of the wind-borne observation sample. Insect counts are scaled or interpolated to compensate for missed observations; adjustment for variation of detectability with range and insect size is also possible. Size distributions for individual days and nights exhibit distinct peaks, representing different insect types, and Simpson and Shannon–Wiener indices of biodiversity are calculated from these. Half-month count, biomass and index statistics exhibit variations associated with the annual cycle and year to year changes that can be attributed to drought and periods of high rainfall. While species-based biodiversity measures cannot be provided, the radar's capacity to estimate insect biomass over a wide area indicates utility for tracking insect population sizes. This article is part of the theme issue ‘Towards a toolkit for global insect biodiversity monitoring’.

Section: Discussionmentioning

confidence: 99%

Monitoring insect numbers and biodiversity with a vertical-beam entomological radar

Drake,

Hao,

Wang

2024

“…birds, bats and insects such as ladybirds [86][87][88]. Most recently, photonic sensors have been shown capable of distinguishing 30 free-flying hoverfly species and their sex by spectral analysis of thin-film wing interference signals [89]. Many modern cars are fitted with high-resolution cameras, lidar and radar systems that are capable of detecting insects.…”

Section: Technology As An Enabler-opening Up New Research Avenuesmentioning

confidence: 99%

Emerging technologies in citizen science and potential for insect monitoring

Sheard,

Adriaens,

Bowler

et al. 2024

Emerging technologies are increasingly employed in environmental citizen science projects. This integration offers benefits and opportunities for scientists and participants alike. Citizen science can support large-scale, long-term monitoring of species occurrences, behaviour and interactions. At the same time, technologies can foster participant engagement, regardless of pre-existing taxonomic expertise or experience, and permit new types of data to be collected. Yet, technologies may also create challenges by potentially increasing financial costs, necessitating technological expertise or demanding training of participants. Technology could also reduce people's direct involvement and engagement with nature. In this perspective, we discuss how current technologies have spurred an increase in citizen science projects and how the implementation of emerging technologies in citizen science may enhance scientific impact and public engagement. We show how technology can act as (i) a facilitator of current citizen science and monitoring efforts, (ii) an enabler of new research opportunities, and (iii) a transformer of science, policy and public participation, but could also become (iv) an inhibitor of participation, equity and scientific rigour. Technology is developing fast and promises to provide many exciting opportunities for citizen science and insect monitoring, but while we seize these opportunities, we must remain vigilant against potential risks. This article is part of the theme issue ‘Towards a toolkit for global insect biodiversity monitoring’.

“…Inexpensive near-infrared photographs ( figure 2 c ) allow for quantification of the equivalent absorption path length of melanin in insect cuticles. Similarly, spectral imaging of wing interference patterns (WIPs) can be done with inexpensive instruments [ 35 ] and the thickness of the chitin membrane can be quantified in each pixel [ 45 ] with a confidence interval in the order of 10 nm. It is conceivable that wing morphology [ 46 ] and quantitative WIPs patterns [ 47 ] alone would be sufficient for identifying particularly closely related insect species at a lower cost than alternative techniques such as DNA barcoding ( figure 3 ).…”

Section: Emerging Technologies In Insect Biomonitoring: 1 Computer Vi...mentioning

confidence: 99%

Towards global insect biomonitoring with frugal methods

Brydegaard,

Pedales,

Feng

et al. 2024

Self Cite

None of the global targets for protecting nature are currently met, although humanity is critically dependent on biodiversity. A significant issue is the lack of data for most biodiverse regions of the planet where the use of frugal methods for biomonitoring would be particularly important because the available funding for monitoring is insufficient, especially in low-income countries. We here discuss how three approaches to insect biomonitoring (computer vision, lidar, DNA sequences) could be made more frugal and urge that all biomonitoring techniques should be evaluated for global suitability before becoming the default in high-income countries. This requires that techniques popular in high-income countries should undergo a phase of ‘innovation through simplification’ before they are implemented more broadly. We predict that techniques that acquire raw data at low cost and are suitable for analysis with AI (e.g. images, lidar-signals) will be particularly suitable for global biomonitoring, while techniques that rely heavily on patented technologies may be less promising (e.g. DNA sequences). We conclude the opinion piece by pointing out that the widespread use of AI for data analysis will require a global strategy for providing the necessary computational resources and training. This article is part of the theme issue ‘Towards a toolkit for global insect biodiversity monitoring’.