Small fluctuations in the recovery of fusaria across consecutive sampling intervals with unmanned aircraft 100 m above ground level

The aerobiology of fungi in the genus Fusarium is poorly understood. Recent work has highlighted the role of Lagrangian coherent structures (LCSs) in the movement of fusaria in the lower atmosphere. Here, we extend this work by examining the relationship between the length of atmospheric sampling intervals with autonomous unmanned aerial vehicles (UAVs) and the recovery of fusaria. UAVs were equipped with an array of eight microbesampling devices with four ‘‘inner’’ sampling arms and four ‘‘outer’’ sampling arms. Each set of arms was used to collect consecutive aerobiological samples during 10 min sampling periods at 100 m above ground level at the Kentland Farm in Blacksburg, Virginia. Fifty-one flights (102 consecutive sampling intervals) were conducted in 2010 and 2011. A correlation analysis showed that the counts of fusaria did not vary between the inner and outer sampling arms from consecutive sampling period of 10 min (r = 0.93, P \ 0.001), and the frequency of colony counts had similar distributions for samples from the inner and outer sampling arms. An analysis of the temporal variation in the collections of Fusarium showed that the similarity between collections decreased over time. This work supports the idea that atmospheric populations of fusaria are well mixed, and large changes in the recovery of fusaria in the lower atmosphere may be attributed to large-scale phenomena (e.g., LCSs) operating across varying temporal and spatial scales. This work may contribute to effective control measures for diseases causes by fusaria in the future.