<i>Baltorussus</i> total makeover:rejuvenation and sex change in an ancient parasitoid wasp lineage

The Orussidae is a small and rare but phylogenetically important family of parasitoid wasps. The fossil record of the family is also very poor. Baltorussus velteni was described from Baltic amber from an allegedly female specimen. This and another recently discovered specimen are examined with microCT scanning and standard microscopy. We reveal that both the holotype and the new specimen are actually males. Furthermore, the results of the microCT scanning allow us to integrate the fossils in a morphological data set assembled for extant Orussidae. Phylogenetic analyses consistently retrieve Baltorussus as a separate basal lineage within the crown group, whereas two Cretaceous fossils are placed as stem group orussids and a Dominican amber fossil in an extant genus. Based on the positions of the fossils, we estimate that the extant Orussidae radiated in the mid-Cretaceous (approx. 100 Ma ago). This is considerably younger than a previously suggested Early Jurassic date (180 Ma ago), which was primarily based on biogeographic evidence

Review of the genus classification of Abiinae (Cimbicidae, Hymenoptera)

Abiinae is the second-largest subfamily in Cimbicidae, a small family of true sawflies (Tenthredinoidea). The subfamily is adequately defined, but the generic classification has been unstable. Currently, only two genera are regarded as valid: Abia Leach, 1817 and Allabia Semenov & Gussakovskij, 1937. We evaluate the generic classification of Abiinae in a phylogenetic context. A total of 32 species (out of 57 described for the subfamily), including the type species of Allabia, Allabia infernalis (Semenov, 1896), are scored for 150 adult morphological characters. Results show some resolution, but only few clades can be circumscribed by consistent character combinations. Most of the characters that have previously been used to define genera are not congruent; consequently, most suggested genus definitions appear to be random character state combinations and few natural groups can be identified. For these reasons, we treat Allabia syn. nov. as a junior synonym of Abia and make the following additional taxonomic changes: Abia infernalis Semenov, 1896 comb. rev. and Abia malaisei (Semenov & Gussakovskij, 1937) syn. nov. For the purpose of long-term stability of the classification of Abiinae, we recommend recognizing only one genus, Abia, within the subfamily

Sambia succinica, a crown group tenthredinid from Eocene Baltic amber (Hymenoptera: Tenthredinidae)

This is the publisher's version, also available electronically from http://booksandjournals.brillonline.com/Sambia succinica gen. et sp.n. from Eocene Baltic amber is described and illustrated. It is apparently the first amber fossil that can be definitively assigned to Tenthredininae. It displays two diagnostic forewing characters for this subfamily: having a bend distally in vein R and the junctions of veins M and Rs + M with vein R being some distance from each other. The variance and possible transitions between the anal vein configurations among the genera in Tenthredininae is briefly discussed

A Nonstationary Markov Model Detects Directional Evolution in Hymenopteran Morphology

Directional evolution has played an important role in shaping the morphological, ecological, and molecular diversity of life. However, standard substitution models assume stationarity of the evolutionary process over the time scale examined, thus impeding the study of directionality. Here we explore a simple, nonstationary model of evolution for discrete data, which assumes that the state frequencies at the root differ from the equilibrium frequencies of the homogeneous evolutionary process along the rest of the tree (i.e., the process is nonstationary, nonreversible, but homogeneous). Within this framework, we develop a Bayesian approach for testing directional versus stationary evolution using a reversible-jump algorithm. Simulations show that when only data from extant taxa are available, the success in inferring directionality is strongly dependent on the evolutionary rate, the shape of the tree, the relative branch lengths, and the number of taxa. Given suitable evolutionary rates (0.1-0.5 expected substitutions between root and tips), accounting for directionality improves tree inference and often allows correct rooting of the tree without the use of an outgroup. As an empirical test, we apply our method to study directional evolution in hymenopteran morphology. We focus on three character systems: wing veins, muscles, and sclerites. We find strong support for a trend toward loss of wing veins and muscles, while stationarity cannot be ruled out for sclerites. Adding fossil and time information in a total-evidence dating approach, we show that accounting for directionality results in more precise estimates not only of the ancestral state at the root of the tree, but also of the divergence times. Our model relaxes the assumption of stationarity and reversibility by adding a minimum of additional parameters, and is thus well suited to studying the nature of the evolutionary process in data sets of limited size, such as morphology and ecolog

Functional morphology and evolution of the sting sheaths in Aculeata (Hymenoptera)

The sting of the Aculeata or stinging wasps is a modified ovipositor- its function (killing or paralyzing prey, defense against predators) and the associated anatomical changes are apomorphic for Aculeata. The change in the purpose of the ovipositor/sting from being primarily an egg laying device to being primarily a weapon has resulted in modification of its handling that is supported by specific morphological adaptations. Here, we focus on the sheaths of the sting (3rd valvulae = gonoplacs) in Aculeata, which do not penetrate and envenom the prey but are responsible for cleaning the ovipositor proper and protecting it from damage, identification of the substrate for stinging, and, in some taxa, contain glands that produce alarm pheromones. The3rd valvulae may be divided into proximal and distal parts. No muscles insert on the 3rd valvulae, and in the process of stinging the movements of the 3rd valvulae are determined by the morphological features of the entire sting apparatus, e.g., the elastic cuticle between the 2nd valvifers and 3rd valvulae and also between the sclerites of the 3rd valvulae. The return of the 3rd valvulae to their resting position is facilitated by the presence of resilin-like proteins in these junctions. The structure and movements of the 3rd valvulae are discussed in the context of the sting function in various groups of Aculeata. The evolution of the 3rd valvulae is discussed- a secondary simplification of the 3rd valvulae structure is observed in representatives of Vespidae, Formicidae, Colletidae, Apidae, Melittidae

The hymenopteran tree of life: evidence from protein-coding genes and objectively aligned ribosomal data

Previous molecular analyses of higher hymenopteran relationships have largely been based on subjectively aligned ribosomal sequences (18S and 28S). Here, we reanalyze the 18S and 28S data (unaligned about 4.4 kb) using an objective and a semi-objective alignment approach, based on MAFFT and BAli-Phy, respectively. Furthermore, we present the first analyses of a substantial protein-coding data set (4.6 kb from one mitochondrial and four nuclear genes). Our results indicate that previous studies may have suffered from inflated support values due to subjective alignment of the ribosomal sequences, but apparently not from significant biases. The protein data provide independent confirmation of several earlier results, including the monophyly of non-xyelid hymenopterans, Pamphilioidea + Unicalcarida, Unicalcarida, Vespina, Apocrita, Proctotrupomorpha and core Proctotrupomorpha. The protein data confirm that Aculeata are nested within a paraphyletic Evaniomorpha, but cast doubt on the monophyly of Evanioidea. Combining the available morphological, ribosomal and protein-coding data, we examine the total-evidence signal as well as congruence and conflict among the three data sources. Despite an emerging consensus on many higher-level hymenopteran relationships, several problems remain unresolved or contentious, including rooting of the hymenopteran tree, relationships of the woodwasps, placement of Stephanoidea and Ceraphronoidea, and the sister group of Aculeata

Dekk og sikkerhet

Denne rapporten handler om lufttrykk i dekk, og dets betydningen for bremsestrekning, økonomi og miljø. I rapporten har vi forklart en del bakgrunnsteori rundt dekk og bremsesystemet til bilen, dette for å gi en bedre forståelse av innvirkende faktorer. Rapporten inneholder også resultatene fra to spørreundersøkelser, der vi blant har annet har fått svar på hvor ofte folk sjekker lufttrykket i dekket, og hvilke typer dekk de kjøper. Den ene tok for seg forbrukere, og ble kryssreferert opp mot forhandlere, der vi også undersøkte hvilke feil de ofte registrerer angående dekk etter endt levetid. Vi har testet hvilken betydning lufttrykket i dekket har for bremselengden, og sett på sikkerhetsmessige aspekter rundt dette. I vårt forsøk på å få et bilde på hva lufttrykket i dekket har å si for miljø og økonomi, har vi benyttet andres undersøkelser og knyttet resultatene våre opp mot disse. Vi fikk oppsiktsvekkende resultater, der endringer på individnivå vil gi store sikkerhetsmessige gevinster, mens det i større skala vil ha en meget positiv innvirkning på miljøet. En del av årsaken til at det vil ha stor samfunnsøkonomisk betydning å få flere til å kontrollere og justere dekktrykket oftere, er en besparelse i klimagassutslipp fra bil på ca 10 %. Når undersøkelser viser at så mange som 70 - 90 % kjører med galt lufttrykk, sier det seg selv at den totale utslippsreduksjonen vil være enorm. Ut i fra dette ser vi at korrekt dekktrykk vil kunne være en av de enkleste og mest effektive metodene for å få bukt med klimagassproblematikken

A total-evidence approach to dating with fossils, applied to the early radiation of the Hymenoptera

unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited