Adult population ecology and egg laying strategy in the ‘cruciata’ ecotype of the endangered butterfly Maculinea alcon (Lepidoptera: Lycaenidae)

摘要

Population dynamics studies in insects mostly focus on a specific life stage of a species and seldom consider different stages. In the framework of our research we studied the population demography of a protected Maculinea alcon 'cruciata' population and the factors that could influence the distribution of eggs. The results of the markrecapture survey showed a relatively short flight period between mid-June and midJuly with clearly marked early peak period. Unlike in many other butterflies, proterandry was not strong. The total population of M. alcon 'cruciata' was estimated at 699 individuals. The survival rate, and consequently the average life span, was relatively low. Generally, males proved to be more mobile than females. Eggs showed a highly aggregated pattern, and egg numbers was positively related to general shoot size, while the number of flower buds and the features of the surrounding vegetation did not display any effect on egg laying. Based on our findings the studied population appears viable, but specific management techniques could ensure optimal conditions for egg laying in this protected butterfly.