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.     

<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.     

Hierarchy length in orphaned colonies of the ant <Emphasis Type="Italic">Temnothorax nylanderi</Emphasis>

Workers of the ant Temnothorax nylanderi form dominance orders in orphaned colonies in which only one or a few top-ranking workers begin to produce males from unfertilized eggs. Between one and 11 individuals initiated 80% of all aggression in 14 queenless colonies. As predicted from inclusive fitness models (Molet M, van Baalen M, Monnin T, Insectes Soc 52:247–256, 2005), hierarchy length was found to first increase with colony size and then to level off at larger worker numbers. The frequency and skew of aggression decreased with increasing size, indicating that rank orders are less pronounced in larger colonies.     

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.     

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.     

Costs and benefits of subordinate queens in colonies of the ant,<Emphasis Type="Italic"> Leptothorax gredleri</Emphasis>

Queens of some species of social insects form dominance hierarchies in which only the top-ranking individual reproduces. Such unequal partitioning of reproduction can be stable when subordinate queens increase their inclusive fitness indirectly by helping to rear a related dominant queen's offspring. We investigated whether subordinate queens of the ant, Leptothorax gredleri, affect the reproductive success of the dominant queen. In laboratory colonies with two queens, first eggs were laid approximately 20 days later than in colonies with a single queen, presumably due to aggressive competition among nestmate queens. Nevertheless, two-queen colonies produced on average more brood than one-queen colonies, although egg laying was completely or almost completely monopolized by one single queen. The presence of a subordinate queen therefore appears to increase the productivity of the dominant.     

Transgenic insect-resistant corn affects the fourth trophic level: effects of<Emphasis Type="Italic"> Bacillus thuringiensis</Emphasis>-corn on the facultative hyperparasitoid<Emphasis Type="Italic"> Tetrastichus howardi</Emphasis>

As hyperparasitoids may have a considerable influence on the control of herbivorous arthropods, analyzing the host-mediated impact of Bacillus thuringiensis-plants (Bt-plants) on hyperparasitoids is of interest. Laboratory-scale experiments were conducted in order to assess the potential effect of Bt-corn leaf material on the facultative hyperparasitoid Tetrastichus howardi (Olliff) (Hymenoptera: Eulophidae), mediated through the herbivore Chilo partellus Swinhoe (Lepidoptera: Crambidae) and its primary parasitoid Cotesia flavipes (Cameron) (Hymenoptera: Braconidae). In the Bt-group, significantly less C. flavipes larvae per host spun cocoons and pupated than in the control, and the mean fresh weight of a single C. flavipes cocoon was significantly reduced compared to the control. All C. flavipes cocoons of one host formed cocoon clusters. T. howardi females of the Bt-group parasitized significantly less cocoon clusters than in the control. Moreover, significantly fewer C. flavipes cocoons per cocoon cluster were successfully parasitized as compared to the control. As a consequence, T. howardi females of the control had more offspring than in the Bt-group. Adult female T. howardi offspring of the Bt-group weighed significantly less than in the control, but there was no significant weight difference between males of both groups. Our results suggest that transgenic insect-resistant plants could affect hyperparasitoids indirectly. However, it remains to be determined whether facultative hyperparasitoids prefer to develop as primary or secondary parasitoids under field conditions.     

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.     

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.     

Heterospecific pairing and hybridization between <Emphasis Type="Italic">Nasutitermes corniger</Emphasis> and <Emphasis Type="Italic">N. ephratae</Emphasis>

The sympatric neotropical termites Nasutitermes corniger and Nasutitermes ephratae are clearly distinguishable based on morphology, nest architecture, defensive secretion composition, and molecular markers. However, given the extensive ecological, geographical, and behavioral overlap of these closely related species, the potential for interbreeding may exist. To explore this possibility, heterospecific pairs were formed experimentally to examine courtship and colony-establishment behaviors, and reproductive potential. Courtship and nest construction behavior occurred in heterospecific pairs in a similar manner to that of conspecific pairs. Survival of pairs depended upon the species of the female partner. N. ephratae females paired with N. corniger males produced as many offspring as conspecific pairs. N. corniger females mated to N. ephratae males, however, produced significantly fewer offspring at 60 days post-establishment than the reciprocal cross or conspecific N. ephratae or N. corniger pairs. This was also the only pairing in which any aggression was observed. Heterospecific pairs and groups formed in mate choice mesocosms, suggesting that species recognition between these two termites is not an important aspect of mate choice. Overall, species mismatch tolerance and hybrid offspring viability are high. The present data, together with previous evidence from defensive secretions and isozyme analysis, suggest that hybridization may periodically occur in nature, and that reproductive barriers between these two species may be incomplete. Hybridization could provide a rare but important source of genetic diversity and may ensure mating opportunities for the more abundant sex of alates in each species.     

<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.     

Alternative mating behaviors of the queen polymorphic ant <Emphasis Type="Italic">Temnothorax longispinosus</Emphasis>

Mating behaviors of ants fall into two categories: female calling, in which a female alate releases pheromones that attract males, and male swarming, in which large male aggregations attract females. Female calling is common in species with queens that return to their natal nest to found colonies dependently after mating, while male swarming is common in species with queens that disperse to found independently. In some species that display both founding strategies, a queen-size polymorphism has evolved in which dependent-founding queens are smaller than independent-founding queens. Dependent founding is likely difficult if gynes (virgin queens) are mating in distant swarms. Therefore, a queen may adopt one or the other mating strategy based on its size and founding behavior. We investigated mating behaviors in the queen-polymorphic ant, Temnothorax longispinosus. Observations in laboratory mating arenas indicated that small gynes exhibited significantly lower flight activity than large gynes. Both forms mated in male swarms, and neither form exhibited female calling. The reduced flight activity of the small morph may facilitate returning to the natal nest after mating, provided the mating swarm is located nearby. Therefore, alternative colony-founding behaviors may be possible without the evolution of female-calling behavior; however, the reduced flight activity of small morphs may require that mating swarms are not distant from the natal nest.     

Circadian consequences of social organization in the ant species<Emphasis Type="Italic"> Camponotus compressus</Emphasis>

The locomotor activity rhythm of different castes of the ant species Camponotus compressus was monitored individually under laboratory light/dark (LD) cycles, and under continuous darkness (DD). The colony of this ant species comprises two sexual castes, the queens and the males, and three worker castes, namely the major, media, and minor workers. The virgin males and virgin queens display rhythmic activity patterns, but the mated queens were arrhythmic while laying eggs, with the rhythmicity resuming soon after egg-laying. Under the LD regime, major workers showed nocturnal patterns, while about 75% of the media workers displayed nocturnal patterns and about 25% showed diurnal patterns. Under the DD regime, most major workers exhibited circadian rhythm of activity with a single steady state, whereas media workers displayed two types of activity patterns, with activity patterns changing after 6–9 days in DD (turn-arounds). The pre-turn-around of the ants that showed nocturnal activity patterns during LD entrainment was <24 h after release into DD, which then became >24 h, after 6–9 days. On the other hand, the pre-turn-around of those ants that exhibited diurnal patterns during LD entrainment was first >24 h after release into DD, and then became <24 h, after 6–9 days. The activity of the minor workers neither entrained to LD cycles nor showed any sign of free-run in DD. It appears that the circadian clocks of the ant species C. compressus are flexible, and may perhaps depend upon the tasks assigned to them in the colony.     

Synthesis and structure-activity relationship of diene modified analogs of<Emphasis Type="Italic"> Matsucoccus</Emphasis> sex pheromones

The biological activity of the Matsucoccus spp. sex pheromones and diene modified analogs has been tested in forests of Israel and Portugal in order to explore the structure-activity relationship of the pine bast scale pheromone/kairomone system. The response of the adult predatory bugs, Elatophilus hebraicus and E. crassicornis and of the brown lacewing, Hemerobius stigma is more selective than that of the conspecific Matsucoccus males. The removal of the terminal methyl group from the diene terminus of both pheromones 1 and 2 eliminates all kairomonal activity but retains moderate pheromonal activity. Addition of a methyl group to the diene terminus of pheromones 1 and 2 sustains full pheromonal and kairomonal activities of the Elatophilus spp. but eliminates entirely the kairomonal activity of H. stigma. Subtle designed alterations in the structure of the diene group, typical of all Matsucoccus pheromones, change the mode of the kairomonal activity markedly.     

<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.     

Comparative morphology and secretion chemistry of the scoli in caterpillars of<Emphasis Type="Italic"> Hyalophora cecropia</Emphasis>

The morphology of the variously coloured scoli (bristle-bearing structures on the integument, producing an exocrine secretion) on caterpillars of Hyalophora cecropia and the secondary chemistry of the discharged secretions have been investigated for the first time and compared. According to our scanning electron microscopic study, the red/orange, yellow and blue coloured groups of these glands differ morphologically. Gas chromatographic-mass spectrometric analyses showed that the patterns of secondary compounds in the respective glandular secretions are also different. Furthermore, the secretion of the penultimate larval instar is chemically distinct from that of the last instar, as are both secretions from the respective haemolymph. The results favour the idea that the differences in scoli colour, morphology and chemistry could affect various predator species differently.Electronic Supplementary Material  Supplementary material is available for this article if you access the article at . A link in the frame on the left on that page takes you directly to the supplementary material.     

Forest clearing and sex ratio in forest-dwelling wood ant <Emphasis Type="Italic">Formica aquilonia</Emphasis>

Sex ratios of ants have been shown to vary with food resource levels in several studies, but it is not known whether forest clear-cutting has any effect on sex ratio of aphid-tending forest-dwelling ants. We investigated whether the offspring sex ratio of the forest dwelling ant Formica aquilonia varied as a response to clear-cutting. We found that the proportion of males was smaller in clear-cuts than in adjacent forests. Our results are among the first showing that anthropogenic changes in forest structures may have a potential to modify sex ratios of social insects and other forest-dwelling animals.     

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.     

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.     

Effect of time on colony odour stability in the ant <Emphasis Type="Italic">Formica exsecta</Emphasis>

Among social insects, maintaining a distinct colony profile allows individuals to distinguish easily between nest mates and non-nest mates. In ants, colony-specific profiles can be encoded within their cuticular hydrocarbons, and these are influenced by both environmental and genetic factors. Using nine monogynous Formica exsecta ant colonies, we studied the stability of their colony-specific profiles at eight time points over a 4-year period. We found no significant directional change in any colony profile, suggesting that genetic factors are maintaining this stability. However, there were significant short-term effects of season that affected all colony profiles in the same direction. Despite these temporal changes, no significant change in the profile variation within colonies was detected: each colony’s profile responded in similar manner between seasons, with nest mates maintaining closely similar profiles, distinct from other colonies. These findings imply that genetic factors may help maintain the long-term stability of colony profile, but environmental factors can influence the profiles over shorter time periods. However, environmental factors do not contribute significantly to the maintenance of diversity among colonies, since all colonies were affected in a similar way.