AbstractA time series analysis of noctuid and sphingid moths caught at light traps in East Africa revealed the existence of sources of periodic variation in catch with three different wavelengths: lunar, annual and four-year. A comparison of catches of Spodoptera exempta (Walker) at different sites showed that site characteristics influence a light trap’s catch and confirmed the northward advance in flight period with season in the early part of the year. This species apparently goes through periods of increased abundance every four years. Of eight other species examined, all but one showed signs of a four-year cycle in abundance, although the peaks occurred in different years. Catches of all nine species were reduced by moonlight, but not equally. The size of the insect influenced its susceptibility to interference by moonlight. This was apparently mediated by the height of flight. High and low flying moths were more strongly influenced by moonlight than those at intermediate heights.
Climate Variability and the Outbreaks of Cholera in Zanzibar, East Africa: A Time Series Analysis
