Suction trap catches of airborne insects in relation to convection in the lower atmosphere

Abstract

Over the last 25 years, since the classic work of Johnson CG. (London: Methuen, 1969) there have been a number of reviews on weather and the movement of insects in the air. These reflect increased field research by entomologists and meteorologists, particularly with the advent of remote-sensing techniques. There is, however, a gap in the literature relating to the influence of convective structures in the atmosphere on insect movement on the small scale (within and between fields). Such papers that have been published on insects and convection tend to report associations with large-scale convective structures (often several hundred kilometres in extent) and generally treat the insects as inert ‘particles’. Conversely, the relatively well-researched subject of insect movement on the small scale tends not to discuss possible convective influences, even though these might have been present. This paper presents the results of a field investigation of the spatial and temporal distributions of insects arriving in a suction trap sampling at a height of 12.2 m over arable land in southern England. It was found that the majority of insects caught were non-randomly distributed in time. The association of such clumps with the passage of convective structures through the atmosphere is discussed.