Assessing the quality of different ant species as partners of a myrmecophilous butterfly

Abstract

We assessed the quality of different ant species as partners of the facultatively myrmecophilous lycaenid butterfly Glaucopsyche lygdamus. We compared disappearance and parasitism rates of G. lygdamus larvae in the field, and development of non-feeding prepupae in the laboratory, when individuals were untended or tended by one of four ant species. Formica podzolica was the only ant species to provide a clear benefit to G. lygdamus, in the form of reduced larval parasitism relative to untended larvae. F. 'neogagates' (F. neogagates + F. lasioides) and Tapinoma sessile were essentially neutral partners, providing no significant cost or benefit for any of the parameters measured. Relative to untended individuals, association with F. obscuripes significantly increased larval disappearance and significantly decreased pupal mass. Thus, F. obscuripes may act as a parasite of the general association between G. lygdamus and ants under certain conditions. Ant species also differed in their persistence as tenders of G. lygdamus larvae once an interaction was established. Over the lifetime of a larva, F. podzolica and F. obscuripes usually remained as the attendant ant species on plants over consecutive census dates, while F. 'neogagates' and T. sessile were frequently replaced, most commonly by F. obscuripes. It remains to be determined if disappearance and developmental outcomes reported here reflect true fitness costs (i.e. reduced survivorship and lower reproductive success) for G. lygdamus. The potential and limitations for specialization in association between G. lygdamus and high quality ant partners are discussed.

Parasitism and ant protection alter the survival of the lycaenid Hemiargus isola

“…Both parasitoids are lycaenid specialists known to attack the larvae of a wide range of genera (Arnaud, 1978;Marsh, 1979; reported by Fraser et al, 2001). Cotesia cyaniridis attacks the lycaenid Glaucopsyche lygdamus feeding on Lupinus sp.…”

“…Cotesia cyaniridis attacks the lycaenid Glaucopsyche lygdamus feeding on Lupinus sp. in Colorado (Pierce & Mead, 1981;Fraser et al, 2001), and another species of Cotesia is known to attack the lycaenid Polyommatus coridon feeding on Hippocrepis comosa in southern France (Schurian et al, 1993). Likewise, the tachinid A. theclarum has been reported to attack other species of lycaenid (Pierce & Mead, 1981;Fraser et al, 2001).…”

“…Although most studies of butterfly-ant interactions have reported that ants confer a benefit of protection to the larvae that they tend, protection from either predation or parasitism has been demonstrated for only six of seven species (six lycaenids, one riodinid) studied to date (Pierce & Mead, 1981;Pierce & Easteal, 1986;Pierce et al, 1987;Fiedler & Maschwitz, 1989;DeVries, 1991;Peterson, 1993;Savignano, 1994;Seufert & Fiedler, 1996;Fraser et al, 2001). Moreover, although the majority of lycaenid-ant associations is facultative in nature (Fiedler, 1991), there is information regarding protection benefits for only three facultatively tended species, and the results differed strikingly (Pierce & Mead, 1981;Pierce & Easteal, 1986;Peterson, 1993;Savignano, 1994).…”

Natural history of the mistletoe-feeding Thereus lomalarga (Lepidoptera, Lycaenidae, Eumaeini) in Colombia

“…During this observation the parasitoid did not land on the larva, but later on, when collected at the end of its 4 th instar, it had been parasitized by the same species of Chalcidinae. Nevertheless, studies designed to measure the effectiveness of the relationship with ants, have shown that percentages of parasitism decrease significantly in the presence of ants (Atsatt 1981a, Pierce & Mead 1981, Pierce & Nash 1999, and that not all the species of ants are equally effective in the defense of larvae (Fraser et al 2001, Kaminski & Rodrigues 2011.…”

Changes in ant community composition caused by 20 years of experimental warming vs. 13 years of natural climate shift

“…In these subalpine meadows, previous research has already demonstrated how a shift in phenology can disrupt several important mutualisms (Saavedra et al 2003, Diez et al 2012, McKinney et al 2012). Due to the important role ants play in this specific system as well as most terrestrial ecosystems as mutualists, predators, and nutrient distribution (Hö lldobler and Wilson 1990), shifts in individual species' distributions can play an important role (Fraser et al 2001). A changing climate selects for success of different genotypes within a given species (Rank andDahlhoff 2002, Skelly et al 2007).…”