Non-Randomness of Fluctuations in the European Corn Borer Ostrinia nubilalis (Hbn.) (Lepidoptera, Crambidae) Long-Term Population Dynamics in Krasnodar Territory

Resumo

The paper presents the results of analysis of long-term (1994–2017) data on the population dynamics of the local bivoltine European corn borer population developing on maize in the east of Krasnodar Territory. The studied factors, namely the season, the generation within a season, and the development stage (eggs, newly hatched and III–V instar larvae, pupae, adults, and egg-laying females), had highly significant effects on population dynamics. The time analysis of normalized deviations of logarithm densities of III–V instar larvae from the mean values using wavelet decomposition revealed significant periodicity in the abundance fluctuations. Thus, our data radically differ from the commonly assumed sporadic nature of the population dynamics of Ostrinia nubilalis. Since the European corn borer has occurred on maize in Krasnodar Territory for at least 100 years, certain biocenotic control mechanisms significantly changing its population dynamics must have appeared during this time.