Two new species of Agatea (Violaceae) endemic to New Caledonia, with some taxonomic notes and a key to New Caledonian species

While working on a treatment of Violaceae for the Flore de Nouvelle-Caledonie et dependences , two new species were recognized, Agatea veillonii Munzinger and A. lecointei Munzinger. These species are here described and illustrated. Some taxonomic notes and a regional identification key are provided.     

Molecular systematics of the caracaras and allies (Falconidae: Polyborinae) inferred from mitochondrial and nuclear sequence data

The Polyborinae is the most diverse subfamily of the Falconidae in terms of both morphology and behaviour, and includes falconet‐shaped birds (Spiziapteryx), arboreal omnivores (Daptrius, Ibycter), as well as terrestrial generalists and scavengers (Caracara, Milvago and Phalcoboenus). The Polyborinae are endemic to the New World, with all but one species (Caracara cheriway) being restricted to Central and South America. Using over 7300 bp of mitochondrial and nuclear sequence data, we aim to clarify the taxonomy and biogeography of the Polyborinae. The genus Milvago was unexpectedly found to be polyphyletic, with Chimango Caracara Milvago chimango being related to the genus Phalcoboenus and Yellow‐headed Caracara Milvago chimachima being sister to Daptrius. Furthermore, very low genetic divergence was found among the four species of the genus Phalcoboenus, with the lowest divergence being between White‐throated Caracara Phalcoboenus albogularis and Mountain Caracara Phalcoboenus megalopterus. Our divergence time analyses revealed that the Polyborinae started to diversify in the Miocene, at about 14 Ma, and that the generalist/scavenger behaviour in the Falconidae appeared between 14 and 6.6 Ma. All speciation events within the caracaras occurred during the Pleistocene. This situation differs from the general pattern described for forest birds, in which most diversification events are older, occurring primarily in the Pliocene and Miocene.     

PANEL PERFORMANCE AND NUMBER OF EVALUATIONS IN A DESCRIPTIVE SENSORY STUDY

The assessor performance is a key point in a sensory evaluation. In particular, at the end of a session, a decrease of the performance can be feared. We propose to analyze this performance with various criteria: usual ones as the main product effect or the error variance; a new one measuring the perceived products variability. The performance can then be studied all along the session from two points of view: in taking into account the only products tested at a given instant (named instantaneous); in taking into account all the products tested up to a given instant (named cumulative). In the presented example, in spite of the large number of products successively tested by each assessor, the instantaneous performance of the panel shows no significant deterioration. Furthermore, when the number of products tested by each assessor increases, more significant product effects can be obtained thanks to the accumulation of the amount of data. This shows that the number of products that can be reasonably studied by one assessor during one session is generally underestimated.     

Theory and practice of combining coagulant fixation and microwave histoprocessing

The German, F. Blum, introduced formalin as a fixative in 1893. Formalin rapidly became popular for hardening and preserving gross human and animal specimens. As a result, microscopy for diagnostic pathology by combining paraffin embedding and formalin fixation was developed. Alcohol-based fixatives have coagulation of proteins as their main preservative effect. Because there is no cross-linking, immunostaining is not compromised, and DNA and RNA is not damaged. Ethyl alcohol was used by Dutch scientists of the 18th century, but was replaced by the cheaper formalin. Addition of low molecular weight polyethylene glycol (PEG) optimized the coagulant fixative, Kryofix. The polyethylene glycol prevents excessive hardening and enhances the speed of coagulation of proteins. Kryofix was used on a large scale for skin biopsies in Leiden between 1987 and 2001. DNA preservation by the formulated coagulant fixative, BoonFix, is related to the concentration of ethyl alcohol, PEG and acetic acid. BoonFix has been used since 2004 in Leiden for over 40,000 diagnostic skin biopsies and more than 100,000 cervical samples. A literature review and three decades of experience with coagulant, formalin-free fixatives in pathology suggest that when health authorities realize that formalin invalidates expensive tests, it might eventually be eliminated legislatively from diagnostic pathology. Finally, coagulant fixation is optimal for microwave histoprocessing where ethyl alcohol is followed by isopropanol.     

DNA‐based discrimination between the sibling species Aphis gossypii Glover and Aphis frangulae Kaltenbach

Abstract Morphologically similar species occur in various groups of insects, including aphid pests. In Europe, Aphis frangulae Kaltenbach and Aphis gossypii Glover (sometimes considered as subspecies) are differentiated usually on the basis of life cycle and host plant. We used a sexual population of A. frangulae collected on the primary host and samples of A. gossypii collected on cucurbits or cotton for the development of molecular markers. DNA sequence data for the gene encoding cytochrome b and for the barcode region of cytochrome oxidase I, as well as a length polymorphism for an intron in the sodium channel para‐type gene discriminated unambiguously between the two taxa. These markers were also used as identification keys for aphids collected on crops belonging to the Solanaceae. The cytochrome b marker differentiates host‐related Aphis gossypii haplotypes, and the para‐type gene intron might be suitable for the resolution of taxonomic problems in other aphid species complexes.     

Experimental evolution of phenotypic plasticity: how predictive are cross-environment genetic correlations?

Genetic correlations are often predictive of correlated responses of one trait to selection on another trait. There are examples, however, in which genetic correlations are not predictive of correlated responses. We examine how well a cross-environment genetic correlation predicts correlated responses to selection and the evolution of phenotypic plasticity in the seed beetle Stator limbatus. This beetle exhibits adaptive plasticity in egg size by laying large eggs on a resistant host and small eggs on a high-quality host. From a half-sib analysis, the cross-environment genetic correlation estimate was large and positive (rA=0.99). However, an artificial-selection experiment on egg size found that the realized genetic correlations were positive but asymmetrical; that is, they depended on both the host on which selection was imposed and the direction of selection. The half-sib estimate poorly predicted the evolution of egg size plasticity; plasticity evolved when selection was imposed on one host but did not evolve when selection was imposed on the other host. We use a simple two-locus additive genetic model to explore the conditions that can generate the observed realized genetic correlation and the observed pattern of plasticity evolution. Our model and experimental results indicate that the ability of genetic correlations to predict correlated responses to selection depends on the underlying genetic architecture producing the genetic correlation.     

Mites as biological tags of their hosts

Movements and spatial distribution of host populations are expected to shape the genetic structure of their parasite populations. Comparing the genetic patterns of both interacting species may improve our understanding of their evolutionary history. Moreover, genetic analyses of parasites with horizontal transmission may serve as indicators of historical events or current demographic processes that are not apparent in the genetic signature of their hosts. Here, we compared mitochondrial variation in populations of the ectoparasitic mite Spinturnix myoti with the genetic pattern of its host, the Maghrebian bat Myotis punicus in North Africa and in the islands of Corsica and Sardinia. Mite mitochondrial differentiation among populations was correlated with both host mitochondrial and nuclear differentiation, suggesting spatial co‐differentiation of the lineages of the two interacting species. Therefore our results suggest that parasite dispersal is exclusively mediated by host movements, with open water between landmasses as a main barrier for host and parasite dispersal. Surprisingly the unique presence of a continental European mite lineage in Corsica was inconsistent with host phylogeographical history and strongly suggests the former presence of European mouse‐eared bats on this island. Parasites may thus act as biological tags to reveal the presence of their now locally extinct host.