Citation: Tartally A, Koschuh A, Varga Z (2014) The re-discovered Maculinea rebeli (Hirschke, 1904): Host ant usage, parasitoid and initial food plant around the type locality with taxonomical aspects (Lepidoptera, Lycaenidae). ZooKeys 406: 25–40. doi: 10.3897/zookeys.406.7124
The taxonomy of the myrmecophilous Maculinea alcon group (Lepidoptera: Lycaenidae) is highly debated. The host-plant and host-ant usage of these butterflies have conventionally been important in their identification. Maculinea ‘rebeli’ has generally been considered to be the xerophilous form of Ma. alcon (Ma. alcon X hereafter) with Gentiana cruciata as initial food plant. However, the type locality and all other known sites of Ma. rebeli are found above the coniferous zone, and are well separated from the lower regions where Ma. alcon X sites are found. Furthermore, no food plant and host ant data for the nominotypic Ma. rebeli have yet been published. Our aim was therefore to identify the host ant(s) of Ma. rebeli around the type locality and compare this with the host ant usage of nearby Ma. alcon X. Nests of Myrmica spp. (Hymenoptera: Formicidae) close to the host plants were opened on one Ma. alcon X (host plant: Gentiana cruciata) and two Ma. rebeli (host plant: Gentianella rhaetica, first record, confirmed by oviposition and emerging larvae) sites just before the flying period, to find prepupal larvae and pupae. Three Myrmica species (My. lobulicornis, My. ruginodis, My. sulcinodis) were found on the two Ma. rebeli sites, which parasitized exclusively My. sulcinodis (22 individuals in 7 nests). On the Ma. alcon X site Myrmica sabuleti and My. lonae were found, with My. sabuleti the exclusive host (51 individuals in 10 nests). Ichneumon cf. eumerus parasitized both butterflies. The results highlight the differentiation of Maculinea rebeli from Ma. alcon X, from both conservation biological and ecological points of view. Thus, it should be concluded that Ma. rebeli does not simply represent an individual form of Ma. alcon but it can be considered as at least an ecological form adapted to high mountain conditions both in its initial food plant and host ant species. In addition, it should be emphasized that Ma. alcon X (= Ma. rebeli auct. nec Hirschke) cannot be synonymised with Ma. rebeli (Hirschke, 1904).
Styrian Alps, nominotypic Maculinea rebeli, Myrmica sulcinodis, My. sabuleti, Gentianella rhaetica, Ichneumon cf. eumerus
Although Maculinea van Eecke, 1915 (Lepidoptera, Lycaenidae) has been synonymised with Phengaris Doherty, 1890 (see:
Maculinea (abbreviated as “Ma.” below) butterflies are endangered species (
There are regional and local differences between the host ant usage of different populations (e.g.
However, a recent paper (
The main reason for our study is that the type locality and the other suggested sites of Maculinea rebeli are above the coniferous zone and well-separated by spruce forests (see Figure 7 in
Three sites within the Hochschwab area (Styrian Alps, Austria; Figs 1–4) were visited between the 22nd and 24th June 2012 (just before the flying period). Two Maculinea rebeli habitats above the coniferous zone were investigated, one at Zeiritz (47.486N, 14.723E, ca 1750 m a.s.l.) and another at Präbichl (47.512N, 14.938E, ca 1600 m a.s.l.). Both sites are sparsely covered by calcareous alpine Sesleria varia (Jacq.) Wettst.-Carex sempervirens Vill. grassland (Seslerio-Semperviretum) vegetation on stony and sunny slopes, with bare limestone rocks (Figs 1–3, compare with Figs 8–10 in
1–2 Maculinea rebeli site at Zeiritz above the coniferous zone (1750 m) 3 Maculinea rebeli site at Präbichl above the coniferous zone (1600 m) 4 Maculinea alcon X site at Sankt Ilgen within the coniferous zone (photo: AK).
5 Maculinea rebeli eggs on Gentianella rhaetica at Präbichl 6 Maculinea rebeli pupae under a stone in a Myrmica lobulicornis nest at Zeiritz 7 Maculinea alcon X pupae and a small larva found in Myrmica sabuleti nest at Sankt Ilgen, arrows sign infections with Ichneumon cf. eumerus (photo: AK).
The host ant specificity of the Maculinea alcon X population at Sankt Ilgen was checked by searching for Myrmica spp. nests within 2 m of Gentiana cruciata plants (see details:
Host ant specificity was calculated based on the number of fully grown butterfly larvae, pupae and exuvia found (i.e., not including small larvae: see results) in two ways (see details:
Altogether 53 Myrmica nests were found on the three sites (Table 1), consisting of 52 nests of five Myrmica species and one empty (presumably recently vacated) but Maculinea-infested nest which was similar in appearance to nearby Myrmica sabuleti nests. Only nests of Myrmica sabuleti and of the closely related (
The recorded Myrmica spp. nests and host ant usage of Maculinea rebeli (at Präbichl and Zeiritz), Maculinea alcon X (at Sankt Ilgen) and Ichneumon cf. eumerus according to the number of large larvae, pupae and exuvia (= “grown Maculinea”) and according to these together with the small larvae (= ”Maculinea in total”). Two measures of host specificity are given: P1 is the 2-tailed probability from the Fisher exact test of heterogeneity in infection of host ant nests and P2 is the probability from a randomization test of ant nests between species (see Materials and Methods).
Site | No. Myrmica nests | Nests Infested with grown Maculinea | No. grown Maculinea (range, P1, P2) | Nests Infested with Maculinea in total | No. Maculinea in total (range, P1, P2) | No. nests Parasitized with Ichneumon cf. eumerus | No. Ichneumon cf. eumerus (range, P1, P2) |
---|---|---|---|---|---|---|---|
Präbichl | lobulicornis 3 | ||||||
(Maculinea rebeli) | ruginodis 1 | ||||||
sulcinodis 13 | 4 | 15 | 6 | 25 | 2 | 8 | |
(2–7, 0.64, 0.62) | (2–7, 0.34, 0.39) | (2–6, 0.43, 0.86) | |||||
Zeiritz | ruginodis 8 | ||||||
(Maculinea rebeli) | sulcinodis 13 | 3 | 7 | 3 | 8 | 1 | 1 |
(2–4, 0.26, 0.35) | (1–3, 0.26, 0.25) | (1–1, 1.00, 1.00) | |||||
Sankt Ilgen | lonae 1 | ||||||
(Maculinea alcon X) | sabuleti 13 | 10 | 51 | 10 | 53 | 9 | 28 |
(1–11, 0.26, 0.50) | (1–11, 0.26, 0.50) | (1–8, 0.36, 0.64) | |||||
empty nest 1 | 1 | 9 | 1 | 9 | 1 | 8 |
Nine nests of Myrmica sulcinodis were infested with 33 Maculinea rebeli larvae, pupae and exuvia at Präbichl and Zeiritz in total, of which 11 caterpillars were so small as to be two-year developing larva after their first winter. There were 15 pupae in total on these two sites, nine of which (60%) proved to be infected with Ichneumon cf. eumerus Wesmael, 1857.
Ten nests of Myrmica sabuleti were infested at Sankt Ilgen with 53 Maculinea alcon X larvae, pupae and exuvia, but only two caterpillars were so small as to be two-year developing larvae. There were nine “orphaned” Maculinea alcon X pupae in the empty nest, which were dirty and showed visible signs of external mould. There were 36 pupae in total, 28 of which (77.8%) were infected with Ichneumon cf. eumerus.
Based on the character of the habitat, the figures published by
8 Maculinea alcon X (Hochschwab area) 9 Maculinea rebeli (Hochschwab area) (photo: AK).
To avoid further confusion, we argue that the true Maculinea rebeli occurs in the Hochschwab area above the coniferous zone (between c.a. 1500 and 2000 m) on slightly covered stony and sunny slopes with uncovered chalk rocks, where Gentianella rhaetica is the only recorded initial host plant, and Myrmica sulcinodis is the only recorded host ant species so far. We still need to confirm the observation of
As far as we know, our observations are the first data on the host ant specificity of Maculinea rebeli around the type locality, and hence, we maintain, of the host ant specificity of Maculinea rebeli. Earlier data about the host ant specificity of Maculinea ‘rebeli’ (e.g.
Our results for Maculinea alcon X, showing Myrmica sabuleti as host, are in agreement with previous studies (e.g.
The presence of Ichneumon cf. eumerus in Maculinea pupae appears to be a good indication that a given ant species is a suitable host ant of Maculinea butterflies (
The one empty Myrmica nest found to be infested with Maculinea alcon X confirms that colonies of various Myrmica species can migrate (
It is almost certain that Manica rubida Latreille, 1802 is not available as a potential host for the populations studied here, despite the presence of this ant in this region. Manica rubida is closely related genetically (
The unusual host ant use of Maculinea rebeli in the Alpine sites could be constrained by the distinctive composition of the Myrmica community found there. Although Maculinea populations can adapt to locally available Myrmica species (e.g.
It should be concluded that Maculinea rebeli does not simply represent an individual form of Maculinea alcon (as considered by
We dedicate this manuscript to the memory of our co-author and friend Anton Koschuh (Fig. 10) who unfortunately could not see the final version of this paper. This survey could not have been carried out without his initiation, enthusiasm and deep knowledge of the habitats. This publication is also dedicated to the memory of Prof. Klaus Horstmann, who provided invaluable assistance in confirming our determinations of Ichneumon eumerus in previous studies (e.g.
We are grateful for the help on the manuscript for David R. Nash, Enikő Tóth, Gábor Sramkó and two anonymous referees.
Anton Koschuh on his way to Zeiritz (23.06.2012) (photo: AT).
AT was supported by a Marie Curie Career Integration Grant within the 7th European Community Framework Programme, by the TÁMOP-4.2.2/B-10/1-2010-0024 project (the project is co-financed by the European Union and the European Social Fund) and by a ‘Bolyai János’ scholarship of the Hungarian Academy of Sciences (MTA). AK was supported by the permission of the Nature Conservation Authority of Styria. ZV was supported by the Hungarian National Science Foundation (OTKA 84071).