Lohman DJ, Liao Q, Pierce NE.
Convergence of chemical mimicry in a guild of aphid predators. Ecological Entomology. 2006;31 :41-51.
AbstractAbstract. 1. A variety of insects prey on honeydew-producing Homoptera and many do so even in the presence of ants that tend, and endeavour to protect, these trophobionts from natural enemies. Few studies have explored the semiochemical mechanisms by which these predators circumvent attack by otherwise aggressive ants. 2. Ants use specific mixtures of cuticular hydrocarbons (CHCs) as recognition labels, but this simple mechanism is frequently circumvented by nest parasites that engage in ‘chemical mimicry’ of their host ants by producing or acquiring a critical suite of these CHCs. 3. Analysis of the CHCs from the North American woolly alder aphid, Prociphilus tessellatus (Homoptera: Aphididae), their tending ants, and aphid predators from three insect orders, Feniseca tarquinius (Lepidoptera: Lycaenidae), Chrysopa slossonae (Neuroptera: Chrysopidae), and Syrphus ribesii (Diptera: Syrphidae), showed that while the CHC profile of each predatory species was distinct, each was chemically more similar to the aphids than to either tending ant species. Further, the CHCs of each predator species were a subset of the compounds found in the aphids’ profile. 4. These results implicate CHCs as a recognition cue used by ants to discriminate trophobionts from potential prey and a probable mechanism by which trophobiont predators circumvent detection by aphids and their tending ants. 5. Although several features of the aphids’ CHC profile are shared among the chemically mimetic taxa, variation in the precision of mimicry among the members of this predatory guild demonstrates that a chemical mimic need not replicate every feature of its model.
2006_lohman_et_al.pdf Eastwood R, Pierce NE, Kitching RL, Hughes JM.
Do ants enhance diversification in lycaenid butterflies? Phylogeographic evidence from a model myrmecophile, Jalmenus evagoras. Evolution. 2006;60 :315-327.
AbstractAbstract. The ant-tended Australian butterfly, Jalmenus evagoras, has been a model system for studying the ecology and evolution of mutualism. A phylogeographic analysis of mitochondrial DNA cytochrome oxidase I sequences from 242 butterflies (615 bp) and 66 attendant ants (585 bp) from 22 populations was carried out to explore the relationship between ant association and butterfly population structure. This analysis revealed 12 closely related butterfly haplotypes in three distinct clades roughly corresponding to three allopatric subpopulations of the butterflies. Minimal genetic diversity and widespread haplotypes within biogeographical regions suggest high levels of matrilineal gene flow. Attendant ants are significantly more diverse than was previously thought, with at least seven well-defined clades corresponding to independent morphological determinations, distributed throughout the range of the butterflies. Nested analysis of molecular variance showed that biogeography, host plant, and ant associate all contribute significantly in explaining variation in butterfly genetic diversity, but these variables are not independent of one another. Major influences appear to come from fragmentation due to large-scale biogeographical barriers, and diversification following a shift in habitat preference. A consequence of such a shift could be codiversification of the butterfly with habitatadapted ants, resulting in apparent phylogenetic concordance between butterflies and ants. The implications of these results are discussed in terms of possible effects of ant attendance on the diversification of Lycaenidae as a whole.
2006_eastwood_et_al.pdf Braby MF, Villa R, Pierce NE.
Molecular phylogeny and systematics of the Pieridae (Lepidoptera: Papilionoidea): higher classification and biogeography. Zoological Journal of the Linnaean Society. 2006;147 :239-275.
AbstractThe systematic relationships of the butterfly family Pieridae are poorly understood. Much of our current understanding is based primarily on detailed morphological observations made 50–70 years ago. However, the family and its putative four subfamilies and two tribes, have rarely been subjected to rigorous phylogenetic analysis. Here we present results based on an analysis of molecular characters used to reconstruct the phylogeny of the Pieridae in order to infer higher-level classification above the generic level and patterns of historical biogeography. Our sample contained 90 taxa representing 74 genera and six subgenera, or 89% of all genera recognized in the family. Three complementary approaches were employed: (1) a combined analysis of a 30 taxon subset for sequences from four gene regions, including elongation factor-1 alpha (EF-1α), wingless, cytochrome oxidase subunit I (COI), and 28S (3675 bp, 1031 parsimony-informative characters), mainly to establish higher-level relationships, (2) a single-gene analysis of the 90 taxon data set for sequences from EF-1α (1066 bp, 364 parsimony-informative characters), mainly to establish lower-level relationships, and (3) an all available data analysis of the entire data set for sequences from the four genes, to recover both deep and shallow nodes. Analyses using maximum parsimony, maximum likelihood and Bayesian inference provided similar results. All supported monophyly for the four subfamilies but not for the two tribes, with the Anthocharidini polyphyletic and the Pierini paraphyletic. The combined and all available data analyses support the following relationships among the subfamilies: ((Pseudopontiinae + Dismorphiinae) + (Coliadinae + Pierinae)), corroborating Ehrlich’s 1958 phenetic hypothesis. On the basis of these analyses, and additional morphological and life history evidence, we propose a reclassification of the subfamily Pierinae into two tribes (Anthocharidini s.s., Pierini s.s.) and two informal groups (Colotis group, Leptosia), with the tribe Pierini s.s. subdivided into three subtribes (Appiadina, Pierina, Aporiina) and three genera (Elodina, Dixeia, Belenois) of uncertain status (incertae sedis). The combined and all available data analyses support the following relationships among the Pierinae: (Colotis group + Anthocharidini s.s. + Leptosia + (Elodina + ((Dixeia + Belenois) + Appiadina + Pierina + Aporiina))). Application of a molecular clock calibrated using fossil evidence and semiparametric rate smoothing suggests that divergence between the Pierina and Aporiina occurred no later than the Palaeocene (> 60 Myr). The minimum estimate for the age of the crown-group of the Pieridae was 112–82 Myr, with a mean of 95 Myr. A historical biogeographical hypothesis is proposed to explain the present-day distribution of the clade Pseudopontiinae + Dismorphiinae, which argues for an origin of the two subfamilies in western Gondwana (Africa + South America) during the Late Cretaceous.
2006_braby_et_al.pdf Moreau CS, Bell CD, Vila R, Archibald SB, Pierce NE.
Phylogeny of the ants: Diversification in the age of angiosperms. Science. 2006;312 :101-104.
AbstractWe present a large-scale molecular phylogeny of the ants (Hymenoptera: Formicidae), based on 4.5 kilobases of sequence data from six gene regions extracted from 139 of the 288 described extant genera, representing 19 of the 20 subfamilies. All but two subfamilies are recovered as monophyletic. Divergence time estimates calibrated by minimum age constraints from 43 fossils indicate that most of the subfamilies representing extant ants arose much earlier than previously proposed but only began to diversify during the Late Cretaceous to Early Eocene. This period also witnessed the rise of angiosperms and most herbivorous insects.
moreau_phylo.pdf