Characterization of intersex production in <Emphasis Type="Italic">Trichogramma kaykai</Emphasis> infected with parthenogenesis-inducing <Emphasis Type="Italic">Wolbachia</Emphasis>

Sexually aberrant individuals, displaying both male and female characteristics, are rare in occurrence but are documented throughout the animal kingdom. In parasitoid wasps of the genus Trichogramma, such individuals typically appear as a result of rearing Wolbachia-infected thelytokous wasps at high temperatures. Sexually aberrant Trichogramma have been referred to interchangeably in the literature as gynandromorphs, sexual mosaics and intersexes. However, accurately used, the terms “gynandromorph” and “sexual mosaic” describe an individual composed of a mixture of genetically distinct tissues corresponding to the sexual phenotypes observed, while “intersex” refers to an individual having a uniform genetic constitution but with some tissues exhibiting sexual phenotypes conflicting with the associated genotype. Here, we investigate the heat-induced production of sexually aberrant offspring by thelytokous Trichogramma kaykai. Aberrant individuals were rare, but each was characterized as one of 11 morphotypes ranging from very feminine to very masculine. Overall, the production of aberrant individuals increased with time from the onset of maternal oviposition. However, while the production of males also increased with time, the degree of masculinity of aberrant individuals did not; the different morphotypes appeared to be produced haphazardly. We conclude that the aberrant individuals produced by T. kaykai are actually intersexes and not gynandromorphs. The wasp's close association with Wolbachia and the absence of intersexes in uninfected populations allow us to discuss a possible origin of the condition.     

<Emphasis Type="Italic">Gnamptogenys hartmani</Emphasis> Wheeler (Ponerinae: Ectatommini): an agro-predator of<Emphasis Type="Italic"> Trachymyrmex</Emphasis> and<Emphasis Type="Italic"> Sericomyrmex</Emphasis> fungus-growing ants

The fungus gardens of fungus-growing ants are a potentially valuable resource for exploitation by natural enemies, but few of these antagonistic interactions have been studied. Here we describe key aspects of the behavioral ecology of Gnamptogenys hartmani (Ponerinae: Ectatommini), a specialized agro-predator of Trachymyrmex and Sericomyrmex fungus-growing ants in Panama. Raiding columns of G. hartmani attack and usurp nests with remarkably little effort: a few intruding workers are sufficient to cause panic among the attine ants and make them abscond from the nest. Both G. hartmani larvae and adults consume the fungus and the host brood, after which the colony migrates to a new fungus-growing ant nest discovered by scouting workers. The morphology of the G. hartmani larval mouthparts is similar to that of Gnamptogenys species with a non-fungal diet. However, we suggest that the presence of long spinules on the larval mandibles in the genus Gnamptogenys, comparable to those found in attine larvae, may have pre-adapted G. hartmani to fungus eating. G. hartmani workers do not actively maintain or modify fungus gardens, which makes them less efficient exploiters than Megalomyrmex, the only other agro-predatory ant species known so far.     

Bee-hawking by the wasp, <Emphasis Type="BoldItalic">Vespa velutina</Emphasis>, on the honeybees <Emphasis Type="BoldItalic">Apis cerana</Emphasis> and <Emphasis Type="BoldItalic">A</Emphasis>. <Emphasis Type="BoldItalic">mellifera</Emphasis>

The vespine wasps, Vespa velutina, specialise in hawking honeybee foragers returning to their nests. We studied their behaviour in China using native Apis cerana and introduced A. mellifera colonies. When the wasps are hawking, A. cerana recruits threefold more guard bees to stave off predation than A. mellifera. The former also utilises wing shimmering as a visual pattern disruption mechanism, which is not shown by A. mellifera. A. cerana foragers halve the time of normal flight needed to dart into the nest entrance, while A. mellifera actually slows down in sashaying flight manoeuvres. V. velutina preferentially hawks A. mellifera foragers when both A. mellifera and A. cerana occur in the same apiary. The pace of wasp-hawking was highest in mid-summer but the frequency of hawking wasps was three times higher at A. mellifera colonies than at the A. cerana colonies. The wasps were taking A. mellifera foragers at a frequency eightfold greater than A. cerana foragers. The final hawking success rates of the wasps were about three times higher for A. mellifera foragers than for A. cerana. The relative success of native A. cerana over European A. mellifera in thwarting predation by the wasp V. velutina is interpreted as the result of co-evolution between the Asian wasp and honeybee, respectively.     

<Emphasis Type="Italic">Robinia pseudoacacia</Emphasis> stump feature based methodology for <Emphasis Type="Italic">in situ</Emphasis> forest degradation assessment

Initiatives for reducing anthropogenic greenhouse gas emissions from deforestation and degradation require transparent and robust methodologies for the estimation of emissions reduction or removal. Although carbon (C) stock change in degradation and devegetation by remote sensing are becoming increasingly powerful, the drivers of degradation, wood collection and harvest dynamics, cannot be understood without “on the ground” sampling. A methodological tool for the quantitative and qualitative analysis of forest degradation is proposed as developed based on a research on the stump history in the black locust degrading stands sampled in southwest Romania. Based on the survey of stumps, the cutting regime and wood extraction is determined over a past period of some 15 years. Stump age classification comprises multiple qualitative criteria (i.e. bark features; adherence of sprouts; cut edge features; etc.). The method allows for a quantitative assessment of wood removal over time, and is suitable for the development of a dynamic baseline and monitoring of degradation avoidance activities.     

Occurrence of <Emphasis Type="Italic">myo</Emphasis>-inositol and alkyl-substituted polysaccharide in the prey-trapping mucilage of <Emphasis Type="Italic">Drosera capensis</Emphasis>

The chemical composition of the exudate mucilage droplets of the carnivorous plant Drosera capensis was investigated using nuclear magnetic resonance spectroscopy. The mucilage was found to contain beside a very large molecular weight polysaccharide a significant amount of myo-inositol. It appears that myo-inositol escaped detection due to the commonly applied methodology on the chemical analysis of plant mucilage, such as dialysis, precipitation of polysaccharide component with alcohol, acid hydrolysis and detection of the resultant monosaccharide (aldose) units. The possible functions of myo-inositol in the mucilage droplets and the fate after being washed off from the leaf tentacles are proposed. On the polysaccharide component, the presence of methyl ester and alkyl chain-like moieties could be confirmed. These lipophilic moieties may provide the prey-trapping mucilage with the unique adhesive property onto the hydrophobic insect body parts, as well as onto the nature’s well-known superhydrophobic surfaces such as the leaves of the sacred lotus plants. A re-evaluation of the mineral components of the mucilage, reported 40 years ago, is presented from the viewpoints of the current result and plants’ natural habitat. A case for re-examination of the well-studied plant mucilaginous materials is made in light of the new findings.     

Homing pigeons (<Emphasis Type="Italic">Columba livia</Emphasis> f. <Emphasis Type="Italic">domestica</Emphasis>) can use magnetic cues for locating food

An experimental group of homing pigeons (Columba livia f. domestica) learned to associate food with a magnetic anomaly produced by bar magnets that were fixed to the bowl in which they received their daily food ration in their home loft; the control group lacked this experience. Both groups were trained to search for two hidden food depots in a rectangular sand-filled arena without obvious visual cues; for the experimental birds, these depots were also marked with three 1.15 × 10⁶ μT bar magnets. During the tests, there were two food depots, one marked with the magnets, the other unmarked; their position within the arena was changed from test to test. The experimental birds searched within 10 cm of the magnetically marked depot in 49% of the test sessions, whereas the control birds searched there in only 11% of the sessions. Both groups searched near the control depot in 11 and 13% of the sessions, respectively. The significant preference of the magnetically marked food depot by the experimental birds shows that homing pigeons cannot only detect a magnetic anomaly but can also use it as a cue for locating hidden food in an open arena.     

Taxonomy of oxalotrophic <Emphasis Type="Italic">Methylobacterium</Emphasis> strains

Most of the oxalotrophic bacteria are facultative methylotrophs and play important ecological roles in soil fertility and cycling of elements. This study gives a detailed picture of the taxonomy and diversity of these bacteria and provides new information about the taxonomical variability within the genus Methylobacterium. Twelve mesophilic, pink-pigmented, and facultatively methylotrophic oxalate-oxidizing strains were included in this work that had been previously isolated from the soil and some plant tissues by the potassium oxalate enrichment method. The isolates were characterized using biochemical tests, cellular lipid profiles, spectral characteristics of carotenoid pigments, G+C content of the DNA, and 16S rDNA sequencing. The taxonomic similarities among the strains were analyzed using the simple matching (S _SM) and Jaccard (S _J) coefficients, and the UPGMA clustering algorithm. The phylogenetic position of the strains was inferred by the neighbor-joining method on the basis of the 16S rDNA sequences. All isolates were Gram-negative, facultatively methylotrophic, oxidase and catalase positive, and required no growth factors. Based on the results of numerical taxonomy, the strains formed four closely related clusters sharing ≥85% similarity. Analysis of the 16S rDNA sequences demonstrated that oxalotrophic, pink-pigmented, and facultatively methylotrophic strains could be identified as members of the genus Methylobacterium. Except for M. variabile and M. aquaticum, all of the Methylobacterium type strains tested had the ability of oxalate utilization. Our results indicate that the capability of oxalate utilization seems to be an uncommon trait and could be used as a valuable taxonomic criterion for differentiation of Methylobacterium species.     

Atlantic sturgeons (<Emphasis Type="Italic">Acipenser sturio</Emphasis>, <Emphasis Type="Italic">Acipenser oxyrinchus</Emphasis>): American females successful in Europe

Recent molecular data on the maternally inherited mitochondrial (mt) DNA have challenged the traditional view that the now extinct Baltic sturgeon population belonged to the European sturgeon Acipenser sturio. Instead, there is evidence that American sea sturgeon Acipenser oxyrinchus historically immigrated into the Baltic Sea. In this study, we test the hypothesis that A. oxyrinchus introgressed into, rather than replaced, the A. sturio population in the Baltic. We established four single nucleotide polymorphisms (SNPs) in the nuclear MHC II antigen gene with a species-specific SNP pattern. Using an ancient DNA approach and two independent lines of molecular evidence (sequencing of allele-specific clones, SNaPshot), we detected both A. sturio and A. oxyrinchus alleles in the available museum material of the now extinct Baltic sturgeon population. The hybrid nature of the Baltic population was further confirmed by very high levels of heterozygosity. It had been previously postulated that the immigration of the cold-adapted A. oxyrinchus into the Baltic occurred during the Medieval Little Ice Age, when temperature likely dropped below the degree inducing spawning in A. sturio. Under this scenario, our new findings suggest that the genetic mosaic pattern in the Baltic sturgeon population (oxyrinchus mtDNA, sturio and oxyrinchus MHC alleles) is possibly caused by sex-biased introgression where spawning was largely restricted to immigrating American females, while fertilization was predominantly achieved by abundant local European males. The hybrid nature of the former Baltic sturgeon population should be taken into account in the current reintroduction measures. Electronic supplementary material  Supplementary material is available in the online version of this article at and is accessible for authorized users.     

<Emphasis Type="Italic">Jeholornis</Emphasis> compared to<Emphasis Type="Italic"> Archaeopteryx</Emphasis>, with a new understanding of the earliest avian evolution

The recently reported Jeholornis represents the only known bird with a complete long skeletal tail except for Archaeopteryx. Two newly discovered specimens referable to Jeholornis provide some important new information about its anatomy. The tail of Jeholornis is much longer than that of Archaeopteryx and comprises a maximum of 27 caudal vertebrae compared with only 23 in Archaeopteryx. More interestingly, the tail feathers are shaped more like those of dromaeosaurs than those of Archaeopteryx. We conclude that the common ancestor of birds must have a more primitive tail than that in Archaeopteryx, confirming the side branch position of Archaeopteryx in the early avian evolution. The synsacrum is composed of six sacrals, representing a transitional stage between Archaeopteryx and more advanced birds. The scapula of Jeholornis has a dorso-laterally exposed glenoid facet, and the coracoid has a supracoracoid foramen. The presence of a pair of fenestrae in the sternum of Jeholornis has further implications for the air-sac system in early birds. Electronic Supplementary Material  The online version of this article (doi: contains supplementary material, which is available to authorized users.     

Habitat segregation mediates predation by the benthic fish <Emphasis Type="Italic">Cottus gobio</Emphasis> on the exotic amphipod species <Emphasis Type="Italic">Gammarus roeseli</Emphasis>

Predation is often considered as one of the most important biotic factor determining the success of exotic species. The freshwater amphipod Gammarus roeseli has widely colonized Western Europe, where it is frequently found in sympatry with the native species (Gammarus pulex). Previous laboratory experiments revealed that G. roeseli may have an advantage over G. pulex through differential predation by native fish (brown trout). Morphological anti-predator defences (spines) were found responsible for lower rates of predation on the invasive G. roeseli. Here, using both field surveys and laboratory experiments, we tested if a differential of predation exists with other fish predators naturally encountered by gammarids. The main predators present in our field site were nocturnal benthic feeders (mainly bullheads, Cottus gobio). Fish diet analysis showed that, compared to its global availability in the river, G. roeseli was less consumed than G. pulex. In the field, however, G. roeseli was found mainly in the aquatic vegetation whereas G. pulex was found in all habitat types. Laboratory experiments in microcosms revealed that G. roeseli was less prone to predation by C. gobio only when vegetation was present. Depending on the type of predator, the differential of predation could therefore be mediated by antipredator behaviour, and a better usage of refuges, rather than by morphological defences.     

<Emphasis Type="Italic">Tenebrio</Emphasis> beetles use magnetic inclination compass

Animals that guide directions of their locomotion or their migration routes by the lines of the geomagnetic field use either polarity or inclination compasses to determine the field polarity (the north or south direction). Distinguishing the two compass types is a guideline for estimation of the molecular principle of reception and has been achieved for a number of animal groups, with the exception of insects. A standard diagnostic method to distinguish a compass type is based on reversing the vertical component of the geomagnetic field, which leads to the opposite reactions of animals with two different compass types. In the present study, adults of the mealworm beetle Tenebrio molitor were tested by means of a two-step laboratory test of magnetoreception. Beetles that were initially trained to memorize the magnetic position of the light source preferred, during the subsequent test, this same direction, pursuant geomagnetic cues only. In the following step, the vertical component was reversed between the training and the test. The beetles significantly turned their preferred direction by 180 degrees. Our results brought until then unknown original findings that insects, represented here by the T. molitor species, use-in contrast to another previously researched Arthropod, spiny lobster-the inclination compass.     

<Emphasis Type="Bold">Chronodisruption and cancer</Emphasis>

Research into health effects of chronodisruption (CD), a relevant disturbance of the circadian organization of physiology, endocrinology, metabolism and behaviour, is evolving at a rapid pace. With regard to malignancies, our synthesis of key experiments indicates that CD can play a causal role for cancer growth and tumor progression in animals. Moreover, our meta-analyses of 30 epidemiological studies evince that flight personnel and shift workers exposed to chronodisruption may have increased breast and prostate cancer risks: summary relative risks (RRs) for investigations of flight personnel and of shift workers suggested a 70 and 40% increase in the risk of breast cancer, respectively, and excess relative risks of prostate cancer in nine studies in flight personnel (40%) and in two studies in male shift workers. There was a remarkable indication of homogeneity of results from the individual studies that contribute to the average statistics. However, in view of doubts about whether the differing assessments of CD can really be regarded as valid reflections of the same causative phenomenon and the lack of control of covariates in the majority of studies, it is premature to conclude that the risk observations reflect a real, rather than spurious, association with CD. The challenge for future epidemiological investigations of the biologically plausible links between chronodisruption and human cancers is to conduct studies which appreciate details of transmeridian travelling, of shift work and of covariates for the development of the diseases.     

The flight of<Emphasis Type="Italic"> Archaeopteryx</Emphasis>

The origin of avian flight is often equated with the phylogeny, ecology, and flying ability of the primitive Jurassic bird, Archaeopteryx. Debate persists about whether it was a terrestrial cursor or a tree dweller. Despite broad acceptance of its arboreal life style from anatomical, phylogenetic, and ecological evidence, a new version of the cursorial model was proposed recently asserting that a running Archaeopteryx could take off from the ground using thrust and sustain flight in the air. However, Archaeopteryx lacked both the powerful flight muscles and complex wing movements necessary for ground takeoff. Here we describe a flight simulation model, which suggests that for Archaeopteryx, takeoff from a perch would have been more efficient and cost-effective than from the ground. Archaeopteryx may have made short flights between trees, utilizing a novel method of phugoid gliding.     

Phylogenetic relationships among morphotypes of <Emphasis Type="Italic">Caesalpinia echinata</Emphasis> Lam. (Caesalpinioideae: Leguminosae) evidenced by <Emphasis Type="Italic">trn</Emphasis>L intron sequences

Caesalpinia echinata (brazilwood or Pernambuco wood) comprises a complex of three morphological leaf variants, characterized by differences in the number and size of the pinnae and leaflets, and occurring in allopatric and sympatric populations. The present study evaluates the utility of the chloroplast DNA trnL intron in a phylogenetic analysis of the three leaf variants along with other species of Caesalpinia and generic relatives. Our study supports the hypothesis that the name C. echinata designates a species complex and provides evidence that one of the forms, the highly divergent C. echinata large-leafleted variant, represents a distinct taxon.     

First evidence of regular common cuckoo, <Emphasis Type="Italic">Cuculus canorus</Emphasis>, parasitism on eastern olivaceous warblers, <Emphasis Type="Italic">Hippolais pallida elaeica</Emphasis>

Coevolution is defined as specialized relationships between species that lead to a reciprocal evolutionary change. A particularly suitable model system for studying coevolution is the interactions between obligate avian brood parasites and their hosts. The common cuckoo (Cuculus canorus, hereafter cuckoo) is a well-known brood parasite, which utilizes a range of smaller passerines as hosts. However, warblers of the genus Hippolais have rarely been reported as being victims of cuckoos, and furthermore, few data exist on the occurrence of antiparasite defenses in these hosts. In this study, we examined possible host–parasite coevolution between cuckoos and eastern olivaceous warblers (Hippolais pallida elaeica, hereafter olivaceous warblers) in three closely situated areas in northwestern Bulgaria. The olivaceous warbler has never been reported to be a regular cuckoo host. However, the present study, carried out in 2001–2003 shows that the olivaceous warbler is regularly and heavily parasitized by the cuckoo in this area. Parasitism rate was high (26.6%, 34/128) and consistent among years, with some variation between areas. The cuckoo egg mimicry was moderately good, and olivaceous warbler rejection rate of such eggs was 50%. Cuckoo eggs laid in olivaceous warbler nests had a whitish to whitish-green ground color, and the majority appeared to be distinctly different from cuckoo eggs found in other host species in the area. The olivaceous warbler proved to be a rather good host for cuckoos as 20.6% (7/34) of cuckoo eggs laid produced fledglings, a breeding success comparable to other suitable hosts in Europe. This is the first in-depth study of brood parasitism in a warbler of the genus Hippolais, and cuckoos parasitizing olivaceous warblers probably represent a previously unknown gens.     

Conspecific flowers of <Emphasis Type="Italic">Sinapis arvensis</Emphasis> are stronger competitors for pollinators than those of the invasive weed <Emphasis Type="Italic">Bunias orientalis</Emphasis>

Biological invasions can affect the structure and function of ecosystems and threaten native plant species. Since most weeds rely on mutualistic relationships in their new environment, they may act as new competitors for pollinators. Pollinator competition is likely to be density dependent, but it is often difficult to disentangle competition caused by flower quality from effects caused by flower quantity. In order to test the effects of the presence and number of flowers of the invasive weed Bunias orientalis on the insect visitation rates in a native species (Sinapis arvensis), we performed two replacement experiments using plants with standardised flower numbers. The visitation rates in S. arvensis were significantly higher than in B. orientalis and the number of insect visits dropped significantly with increasing density of S. arvensis flowers. These results suggest that intraspecific competition among flowers of S. arvensis is stronger than the competitive effect of alien flowers. As flowers of B. orientalis do not seem to distract visitors from S. arvensis, it is unlikely that pollinator competition between these two plant species plays a crucial role. However, it cannot be excluded that mass blossom stands of B. orientalis may distract flower visitors from native species.     

The ladybird<Emphasis Type="Italic"> Thalassa saginata</Emphasis>, an obligatory myrmecophile of<Emphasis Type="Italic"> Dolichoderus bidens</Emphasis> ant colonies

The larvae and pupae of the ladybird Thalassa saginata develop inside colonies of the dolichoderine ant Dolichoderus bidens. This association is the first specific and obligatory relationship recorded between ants and ladybirds. The ants provide shelter and protection to the larvae but the diet of the latter remains unclear. The integration of T. saginata larvae into the ant colonies is achieved by mimicking the cuticular patterns of the ants brood. Moreover, the larvae secrete substances from their hairs and anal gland that are likely to enhance their attractiveness.     

Interspecific mating of the introduced bumblebee <Emphasis Type="Italic">Bombus terrestris</Emphasis> and the native Japanese bumblebee <Emphasis Type="Italic">Bombus hypocrita sapporoensis</Emphasis> results in inviable hybrids

The bumblebee Bombus terrestris is not only an effective pollinator, but also a potential invasive alien species outside its native range. Recently, nearly 30% of queens of the Japanese native species Bombus hypocrita sapporoensis and B. hypocrita hypocrita were estimated to copulate with B. terrestris males in the field, suggesting that indigenous bumblebees could be genetically deteriorated through hybrid production with the introduced species. In this study, we evaluated hybrid production between the introduced B. terrestris and the indigenous B. hypocrita sapporoensis under laboratory conditions. The hatching rate of eggs derived from interspecific matings was 0% and 8.6% depending on the direction of the cross, which was significantly lower than that from intraspecific matings of B. terrestris (76.9%) and B. hypocrita sapporoensis (78.9%). Genetic studies using microsatellite markers revealed that both haploid and diploid individuals were present in the egg stage, whereas all hatched larvae were haploid. In addition, histological studies revealed that eggs derived from interspecific matings terminated development 2 days after oviposition. These results strongly suggested that eggs derived from interspecific matings are inviable due to post-mating isolation mechanisms. Mass release of exotic pollinators could cause serious population declines of native bumblebee species.     

Epicuticular wax of large and small white butterflies,<Emphasis Type="Italic"> Pieris brassicae</Emphasis> and<Emphasis Type="Italic"> P. rapae crucivora</Emphasis>: qualitative and quantitative comparison between diapause and non-diapause pupae

We compared the quantity and quality of the epicuticular wax of diapause and non-diapause pupae in two closely related Pieris species, P. brassicae and P. rapae crucivora. Main components of their epicuticular wax were identified as hydrocarbons. In P. brassicae, more than 95% of hydrocarbons were saturated regardless of whether the pupae were in diapause or not. In P. rapae crucivora, 93% of hydrocarbons were saturated in non-diapause pupae whereas in diapause pupae 41% were saturated and 59% unsaturated. From measurements of body surface area by nuclear magnetic resonance microimaging, we calculated the average thickness of the wax layer. The thickness in diapause and non-diapause pupae of P. brassicae was 800 and 160 nm, respectively. In P. rapae crucivora, the thickness was 195 nm in diapause and 11 nm in non-diapause. This is the first report to clarify the compositional difference in epicuticular wax between diapause and non-diapause pupae.