Statistical analysis reveals the onset of synchrony in sparse swarms of Photinus knulli fireflies

Flash synchrony within firefly swarms is an elegant but elusive manifestation of collective animal behaviour. It has been observed, and sometimes demonstrated, in a few populations across the world, but exactly which species are capable of large-scale synchronization remains unclear, especially in low-density swarms. The underlying question which we address here is: how does one qualify a collective flashing display as synchronous, given that the only information available is the time and location of flashes? We propose different statistical approaches and apply them to high-resolution stereoscopic video recordings of the collective flashing of Photinus knulli fireflies, hence establishing the occurrence of synchrony in this species. These results substantiate detailed visual observations published in the early 1980s and made at the same experimental site: Peña Blanca Canyon, Coronado National Forest, Arizona, USA. We also remark that P. knulli's collective flashing patterns mirror that observed in Photinus carolinus fireflies in the Eastern United States, consisting of synchronous flashes in periodic bursts with rapid accretion and quick decay.

A Coordinated, Risk-Based, National Forest Biosecurity Surveillance Program for Australian Forests

Australia has a comprehensive plant biosecurity system, with the Australian Government responsible for pre-border (e.g., off-shore compliance) and border (e.g., import inspections) activities, while state governments undertake a variety of post-border activities (e.g., post-border surveillance, management of pest incursions, and regulation of pests) designed to reduce alien pest and pathogen arrival and establishment. Once an alien pest or pathogen has established and spread, its management becomes the responsibility of the land manager. There has been a growing understanding among plant industries of the need to be more engaged in post-border biosecurity activities, including resourcing and undertaking early detection surveillance and contingency planning. Here we summarize Australia’s broader plant biosecurity system along with current forest-specific biosecurity surveillance activities. We describe the development of a proposed forest biosecurity partnership between the Australian Government, state governments and the forest sector to establish a post-border, risk-based National Forest Pest Surveillance Program. We outline why there is a recognized need for such a program, how it would improve biosecurity outcomes in relation to forests, its component activities, and key stakeholders and beneficiaries.