Rapid radiation of ant parasitic butterflies during the Miocene aridification of Africa.

Africa has undergone a progressive aridification during the last 20 My that presumably impacted organisms and fostered the evolution of life history adaptations. We test the hypothesis that shift to living in ant nests and feeding on ant brood by larvae of phyto-predaceous Lepidochrysops butterflies was an adaptive response to the aridification of Africa that facilitated the subsequent radiation of butterflies in this genus. Using anchored hybrid enrichment we constructed a time-calibrated phylogeny for Lepidochrysops and its closest, non-parasitic relatives in the Euchrysops section (Poloyommatini). We estimated ancestral areas across the phylogeny with process-based biogeographical models and diversification rates relying on time-variable and clade-heterogeneous birth-death models. The Euchrysops section originated with the emerging Miombo woodlands about 22 million years ago (Mya) and spread to drier biomes as they became available in the late Miocene. The diversification of the non-parasitic lineages decreased as aridification intensified around 10 Mya, culminating in diversity decline. In contrast, the diversification of the phyto-predaceous Lepidochrysops lineage proceeded rapidly from about 6.5 Mya when this unusual life history likely first evolved. The Miombo woodlands were the cradle for diversification of the Euchrysops section, and our findings are consistent with the hypothesis that aridification during the Miocene selected for a phyto-predaceous life history in species of Lepidochrysops, with ant nests likely providing caterpillars a safe refuge from fire and a source of food when vegetation was scarce.

Taxonomic Delineation of the Old World Species Stomphastis thraustica (Lepidoptera: Gracillariidae) Feeding on Jatropha gossypiifolia (Euphorbiaceae) that Was Collected in the New World and Imported as a Biocontrol Agent to Australia.

We provide the identification and species delineation of this biocontrol agent as Stomphastis thraustica (Meyrick in Trans Ent Soc Lond 80(1):107-120, 1908) belonging to the family Gracillariidae. We clarify the distribution pattern of S. thraustica, its host plant preferences, and present taxonomic and molecular diagnoses based on original morphological and genetic data as well as data retrieved from historic literature and genetic databases. Following our own collecting efforts in three continents Africa, South America, and Australia as well as our study of historic museum collection material, we present many new distribution records of S. thraustica for countries and territories in the world including the new discovery of this species in the Neotropical region and we report its introduction in Australia as a biocontrol agent. Using mitogenomic and COI gene data, we clarified that the closest relative of S. thraustica is Stomphastis sp. that occurs in Madagascar and Australia and feeds on the same host plant as S. thraustica - Jatropha gossypiifolia L. (Euphorbiaceae). The molecular sequence divergence in the mitochondrial DNA barcode fragment between these two closely related species S. thraustica and Stomphastis sp. is over 5.7% supporting that they are different species.

Co-doping of scandia-zirconia electrolytes for SOFCs.

Scandia stabilised zirconias offer much better electrical performance than conventional yttria stabilised materials; however, the limited availability and high cost of scandia have generally limited interest in its application in fuel cells. Political and economic changes over the last decade have significantly enhanced scandia's availability, rendering it worth considering for commercial application, even though there is still some uncertainty about its ultimate market price. A small addition of 2 mol% yttria to scandia stabilised zirconia results in stabilisation of the cubic phase and so avoids the major phase changes that occur on thermal cycling of scandia substituted zirconias, which might be expected to be detrimental to long term electrolyte stability. This addition of yttria does slightly impair the electrical conductivity of the scandia stabilised zirconia, although this can be reversed by further addition of ceria. Samples which are cubic throughout the studied temperature range basically show two linear conductivity regions in Arrhenius conductivity plots. A key observation is that the low temperature activation energy decreases and the high temperature activation energy increases as yttrium content increases and scandium content decreases. This correlates with the strength of short-range order as indicated by neutron and electron diffraction studies. Although scandia substitution increases conductivity and decreases high temperature activation energy, it also increases the tendency to short-range ordering at lower temperatures, resulting in a significant increase in activation energy for conduction. This is attributed to the ionic size of the Sc ion which favours a lower coordination number than that associated with ideal fluorite phases. It should also be realised that Zr, which has a similar size to Sc, also prefers a lower coordination number than is ideal for fluorite hence driving the tendency for short-range order in zirconia fluorites.