Egg-laying preferences of the xerophilous ecotype of Maculinea alcon (Lepidoptera: Lycaenidae) in the Aggtelek National Park

Abstract

Abstract. The oviposition sites of the xerophilous ecotype of M. alcon (= "Maculinea rebeli") were surveyed in the managed (transitional) zone of the Aggtelek National Park and Biosphere Reserve in Northern Hungary. The M. alcon population is distributed over a territory of about 3 ha. In 2001, habitat reconstruction with selective cutting of shrubs and mowing, was started in this area. The number of stems of Gentiana cruciata (the food plant for the young larvae) and M. alcon eggs layed on them were counted in a selected area within this 3 ha: before (in 1992, 1993 and 1998) and after habitat reconstruction (in 2003, 2004 and 2005). In 2004 and 2005, a detailed study was carried out in order to detect potentially significant factors influencing the egg laying behaviour of females. The average number of intact flowering stems per quadrate was 2.68 and was clearly decreasing before management started. In contrast, there were five times higher (15.06) and increasing numbers of stems per quadrate right after habitat reconstruction. The two periods also differed in the percentage of flowering stems, which was very low before habitat reconstruction. The average number of eggs per square was low (6.8) and fluctuated considerably before management started. In contrast, the egg count was high (160.3) and increased consistently after the site was managed. The short grass sward created in the area proved to be advantageous both for the growth of the host plant and for the Maculinea population. The egg laying preference of the females was positively affected by the number of stems per clump, the height of the stems, the number of whorls with flowers and the difference between the height of the stems of the host plant and the surrounding vegetation. Significantly more eggs were found on large clumps of stems than expected on the basis of their availability for egg-laying. Egg counts were strongly correlated with all the measured characteristics of the food plant, which significantly correlated with each other. The interaction term indicated that the number of whorls with flowers is slightly more influential for egg laying than the other characteristics. There were significantly more eggs on the adaxial surface of the leaves and flower buds than on other parts of the food plant.

Changes in host ant communities of Alcon Blue butterflies in abandoned mountain hay meadows

“…In summary, our results suggest that abandonment, that is, the termination of management, leads to changes that are unfavourable to the xerophilous form of M. alcon populations in the Bükk Mountains. The same trend was clear in the nearby Aggtelek region, but was successfully reversed by resuming management (Árnyas et al ., ). It should be noted that caution is warranted in the interpretation of our results because the management history of the study sites was sketchy and more details on, for example, livestock grazing pressure or frequency of mowing could have further refined the trends found.…”

Differences in oviposition strategies between two ecotypes of the endangered myrmecophilous butterfly Maculinea alcon (Lepidoptera: Lycaenidae) under unique syntopic conditions

“…() and Fürst and Nash () also found that stem length and the number of flowers positively influence the egg‐laying behaviour of M. alcon . Similarly, other studies (Dolek et al ., ; Árnyas et al ., ) have shown that stem length positively influences the egg laying of M . ‘ rebeli ’.…”

“…Within‐species variations among ecotypes may be important for preserving endangered species, due to the ecotypes’ differential response to environmental changes (Bálint et al ., ; Sielezniew et al ., ). Although egg‐laying behaviour has already been studied in the case of both forms of M. alcon (see Dolek et al ., ; Árnyas et al ., , for M . ‘ rebeli ’; Van Dyck et al ., ; Nowicki et al ., ; Fürst & Nash, ; Van Dyck & Regniers, for M. alcon ; and Thomas & Elmes, for both), it has never been analysed in syntopic conditions and a comparison between the egg‐laying behaviour of the two ecotypes has not been made.…”

“…Within-species variations among ecotypes may be important for preserving endangered species, due to the ecotypes' differential response to environmental changes (B alint et al, 2012;Sielezniew et al, 2012). Although egglaying behaviour has already been studied in the case of both forms of M. alcon (see Dolek et al, 1998;Arnyas et al, 2006Arnyas et al, , 2009Van Dyck et al, 2000;Nowicki et al, 2005;F€ urst & Nash, 2010;Van Dyck & Regniers, 2010 for M. alcon; for both), it has never been analysed in syntopic conditions and a comparison between the egg-laying behaviour of the two ecotypes has not been made. The ecological and behavioural differences between these two forms manifested in different host plant use, implying differences in egg-laying preferences, and separation of flight periods makes these populations perfect candidates for studies regarding syntopic isolation processes.…”

Relative importance of density-dependent regulation and environmental stochasticity for butterfly population dynamics

“…For M.teleius eggs, counting eggs is not feasible because this species lays its eggs deep within the inflorescences of S. officinalis flowers . Certain plants may be preferred for oviposition over others due to their location, appearance or phenological differences (Figurny and Woyciechowski 1998;Bonelli et al 2005;Nowicki et al 2005d;Musche et al 2006;Arnyas et al 2006Arnyas et al , 2009. However, even if the majority of eggs are concentrated on 30-60% of the foodplants, as found in our and other studies (Figurny and Woyciechowski 1998;Wynhoff 2001;Nowicki et al 2005dNowicki et al , 2007Arnyas et al 2009), it still seems justified to conclude that the probability of larval competition on foodplants is negligible at the population scale, even though more than one egg may occasionally be laid on a single flower (as we sometimes observed for M. alcon).…”