Competitive Exclusion among Fig Wasps Achieved via Entrainment of Host Plant Flowering Phenology

Molecular techniques are revealing increasing numbers of morphologically similar but co-existing cryptic species, challenging the niche theory. To understand the co-existence mechanism, we studied phenologies of morphologically similar species of fig wasps that pollinate the creeping fig (F. pumila) in eastern China. We compared phenologies of fig wasp emergence and host flowering at sites where one or both pollinators were present. At the site where both pollinators were present, we used sticky traps to capture the emerged fig wasps and identified species identity using mitochondrial DNA COI gene. We also genotyped F. pumila individuals of the three sites using polymorphic microsatellites to detect whether the host populations were differentiated. Male F. pumila produced two major crops annually, with figs receptive in spring and summer. A small partial third crop of receptive figs occurred in the autumn, but few of the second crop figs matured at that time. Hence, few pollinators were available to enter third crop figs and they mostly aborted, resulting in two generations of pollinating wasps each year, plus a partial third generation. Receptive figs were produced on male plants in spring and summer, timed to coincide with the release of short-lived adult pollinators from the same individual plants. Most plants were pollinated by a single species. Plants pollinated by Wiebesia sp. 1 released wasps earlier than those pollinated by Wiebesia sp. 3, with little overlap. Plants occupied by different pollinators were not spatially separated, nor genetically distinct. Our findings show that these differences created mismatches with the flight periods of the other Wiebesia species, largely ‘reserving’ individual plants for the resident pollinator species. This pre-emptive competitive displacement may prevent long term co-existence of the two pollinators.     

Mitochondrial ribosomal proteins in Xenopus laevis/X. mulleri interspecific hybrids.

The large subunits of mitochondrial ribosomes were isolated from two related frog species, Xenopus laevis and X. mulleri, and their proteins were compared by two-dimensional polyacrylamide gel electrophoresis. Three of the proteins observed in X. laevis are absent from X. mulleri, and four of the proteins observed in X. mulleri are absent from X. laevis. More than these seven such species-specific proteins may occur.Reciprocal crosses between frogs of the two species gave two groups of F1 hybrids. Nuclear genes in these hybrids derive equally from both species, while mitochondrial DNA (and therefore mitochondrial rRNA) derived exclusively from the maternal species. Electrophoretic analyses of the large subunit proteins of these F1 animals revealed that four of the species-specific proteins are present only when their corresponding species was the mother. While this result is consistent with the coding of these four proteins by mitochondrial DNA, it does not provide evidence against nuclear coding of these proteins. A fifth protein is absent from both F1 hybrids. A sixth is present in both F1 hybrids, and a seventh is present only when its corresponding species was the father. We conclude that at least these latter two mitochondrial ribosomal proteins are encoded by nuclear genes.     

Ultrasonic Vocalizations of Male Mice Differ among Species and Females Show Assortative Preferences for Male Calls

Male house mice (Mus musculus) emit ultrasonic vocalizations (USVs) during courtship, which attract females, and we aimed to test whether females use these vocalizations for species or subspecies recognition of potential mates. We recorded courtship USVs of males from different Mus species, Mus musculus subspecies, and populations (F1 offspring of wild-caught Mus musculus musculus, Mus musculus domesticus (and F1 hybrid crosses), and Mus spicilegus), and we conducted playback experiments to measure female preferences for male USVs. Male vocalizations contained at least seven distinct syllable types, whose frequency of occurrence varied among species, subspecies, and populations. Detailed analyses of multiple common syllable types indicated that Mus musculus and Mus spicilegus could be discriminated based on spectral and temporal characteristics of their vocalizations, and populations of Mus musculus were also distinctive regardless of the classification model used. Females were able to discriminate USVs from different species, and showed assortative preferences for conspecific males. We found no evidence that females discriminate USVs of males from a different subspecies or separate populations of the same species, even though our spectral analyses identified acoustic features that differ between species, subspecies, and populations of the same species. Our results provide the first comparison of USVs between Mus species or between Mus musculus subspecies, and the first evidence that male USVs potentially facilitate species recognition.     

Mating Behavior and Performance in the Two Cosmopolitan Mealybug Species Planococcus citri and Pseudococcus calceolariae (Hemiptera: Pseudococcidae)

Mating strategies of mealybugs were investigated using two heterogeneric cosmopolitan species as case study: Planococcus citri (Risso) and Pseudococcus calceolariae (Maskell). Male mating behavior of the studied species differed in respect to mate selection, and frequency and duration of copulation. Females played an active role in mate selection, by either facilitating or resisting copulation. This is a first evidence of female sexual active behavior in scale insects. In both species, male predisposition to mate was affected by previous exposition to light. The frequency of courtship and copulation decreased with the age of females for Pl. citri but not for Ps. calceolariae. Mating frequency increased with female colony density in both species.     

Vertical distribution of chitons (Mollusca: Polyplacophora) in the rocky intertidal zone of central Chile

The patterns of vertical distribution of chitons in various exposed rocky shore habitats of central Chile are described. The density and size of the individuals were determined at different levels on intertidal rock walls, in pools and on boulders. A group of four species was found on rock walls while another group of four species was found in tidal pools and on boulders. The species showed vertical separation on rock walls and segregation according to a range of increasing frequency of water movement in pools and on boulders. Only the two species with largest adult individuals (Acanthopleura echinata (Barnes) and Chitonlatus Sowerby) showed vertical segregation in size. Small-sized species and small individuals of large-sized species were found higher on rock walls or in zones where water movement is less; large chitons occur in zones of greatest water impact. This suggests that water movement may be a significant factor in setting the lower limits of distribution of these herbivores. Some of the species examined were extremely abundant (600·m^-2) with densities of one to two orders of magnitude greater than for other chiton species elsewhere.     

Sexual Selection, Epistasis and Species Boundaries in Sympatric Hawaiian Picture-winged Drosophila

The Hawaiian picture-winged flies in the genus Drosophila are a spectacular example of rapid evolutionary diversification in which sexual selection is considered an important mechanism for reproductive isolation and speciation. We investigated the behavioral reproductive isolation of two closely related and sympatric Hawaiian picture-winged Drosophila species, D. silvestris and D. heteroneura, which are known to hybridize in nature and produce viable and fertile hybrids. We compared the mating success of parental, F1 and backcross males in pairings with D. heteroneura females. The F1 males were produced by mating D. heteroneura males with D. silvestris females, and the backcross males were produced by mating F1 females with D. heteroneura males. The mating success of backcross males paired with D. heteroneura females were significantly reduced relative to that of parental and F1 males. This reduced mating success occurred primarily at a late stage of courtship where female choice of mate may be important. Two- and three-gene models demonstrate that epistasis involving a few genes could account for the observed variation in male mating success. These results are consistent with negative epistasis in the backcross generation and support the importance of sexual selection and negative epistasis in the evolution and maintenance of these species.     

A review of the genus Bothynogria Borchmann, 1915 with descriptions of one new species and two new record species from China (Coleoptera: Tenebrionidae: Lagriinae: Lagriini: Lagriina)

The genus Bothynogria Borchmann, 1915 is reviewed, with a key to all known seven species provided in the present paper. A new species Bothynogria nigripennis sp. n., and two new record species for China, Bothynogria bicolor (Kollar et Redtenbacher, 1848) and Bothynogria meghalayana Merkl, 1990, are identified and redescribed. The habitus, male antennae and aedeagus are photographed and presented for all known species except for Bothynogria bhutanica. Ecological information and intraspecific variations are also provided for Bothynogria calcarata.www.zoobank.org/urn:lsid:zoobank.org:pub:5D8BFBCD-73AF-4AD4-94DE-3F24ECE31C1D.     

Genetic assessment of the effects of self-fertilization in a Lilium L. hybrids using molecular cytogenetic methods (FISH and ISSR)

Self-fertilization (also termed selfing) is a mode of reproduction that occurs in hermaphrodites and has evolved several times in various plant and animal species. A transition from outbreeding to selfing in hermaphroditic flowers is typically associated with changes in flower morphology and functionality. This study aimed to identify genetic effects of selfing in the F2 progeny of F1 hybrid developed by crossing Lilium lancifolium with the Asiatic Lilium hybrid ‘Dreamland.’ Fluorescence in situ hybridization (FISH) and inter-simple sequence repeats (ISSR) techniques were used to detect genetic variations in plants produced by selfing. The FISH results showed that F1 hybrid were similar to the female parent (L. lancifolium) regarding the 45S loci, but F2 individuals showed variation in the number and location of the respective loci. In F2 progeny, F2-2, F2-3, F2-4, F2-5, and F2-8 hybrids expressed two strong and one weak 5S signal on chromosome 3, whereas F2-7 and F2-9 individuals expressed one strong and two weak signals. Only two strong 5S signals were detected in an F2-1 plant. The ISSR results showed a maximum similarity value of 0.6269 between the female parent and the F2-2 hybrid. Regarding similarity to the male parent, a maximum value of 0.6119 was found in the F2-1 and F2-2 hybrids. The highest genetic distance from L. lancifolium and the Asiatic Lilium hybrid ‘Dreamland’ was observed in the F2-4 progeny (0.6352 and 0.7547, respectively). Phylogenetic relationships showed that the F2 progeny were closer to the male parent than to the female parent. Self-fertilization showed effects on variation among the F2 progeny, and effects on the genome were confirmed using FISH and ISSR analyses.     

Characteristics of Fusobacterium ulcerans,a New and Unusual Species Compared with Fusobacterium varium and Fusobacterium mortiferum

Fusobacterium ulcerans is a newly described obligately anaerobic Gram-negative, non-spore-forming rod [1] that has been isolated from tropical ulcers. Two morphotypes were described: one resemblingFusobacterium varium and the other Fusobacterium mortiferum[1]. Because of the weak or negative fermentation reactions of most fusobacteria, the standard carbohydrate tests used for identification of anaerobe organisms are of little use for identification, and other rapid and simple methods are needed. We characterized eight F. ulcerans strains using conventional biochemical testing. We further analysed these strains by PCR employing a single non-specific primer AP3 and by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) of whole cell proteins. PCR using a self-designed pair of primers for the amplification of the spacer (intergenic) region between the 16S and 23S rRNA genes, led to the development of genetic markers for species identification. All F. ulcerans clinical isolates appeared very similar to each other in all the test parameters, but were distinctly different from the type strains of the two phenotypically similar species, F. mortiferum and F. varium. High similarity in PCR- and protein-profiles also raise the possibility that all these F. ulcerans strains came from one clone. We noted significant differences among the strains of F. mortiferum and F. varium.     

Response of plant and gastropod species to knotweed invasion

Invasive species of the knotweed complex (Fallopia sp.) have repeatedly been shown to decrease diversity of native local biota. While effects on plant species richness are well established, effects on invertebrate and in particular gastropod species richness are less well understood. We recorded cover of plant species and diversity and abundance of gastropod species in four plots (1 m × 1 m) with Fallopia japonica and compared these to paired control plots without F. japonica at 15 sites along the river Birs (Switzerland) in early summer (June) and autumn (September). Knotweed and control plots did not differ in site characteristics and soil parameters.Average plant species richness in F. japonica plots was 50% lower compared to control plots. This reduction was significant for woody species as well as for herbaceous species. However, species richness of early flowering annuals did not differ significantly. Among the species most affected by knotweed were hop (Humulus lupulus) and European spindle tree (Euonymus europaeus) but also stand-forming species such as nettle (Urtica dioica) or ground elder (Aegopodium podagraria).Average snail species richness was significantly reduced in F. japonica plots. The reduction was pronounced in large (≥5 mm shell size) and long-lived (>2 years) snail species but not in slugs or small and short-lived snails. For example, large snails such as the Roman snail (Helix pomatia, ?85%) or the red-listed species Bradybaena fruticum (?93%), showed reduced abundances in F. japonica compared to control plots. In contrast, the red-listed but small Vertigo pusilla (+92%) had higher abundances in F. japoinca plots. Principal component analyses revealed little overlap in plant communities or community composition of large snail species between F. japonica and control plots. Taken together, knotweed invasion decreased the cover of most plant species and abundance of large and long-lived gastropods.     

Effect of Ferula assafoetida essential oil on some biological and behavioral traits of Trichogramma embryophagum and T. evanescens

Fumigant toxicity of the essential oil of Ferula assafoetida L. (Umbelliferae), a potent botanical insecticide against carob moth, was investigated under laboratory conditions on the fitness of two carob moth egg parasitoids, Trichogramma embryophagum (Hartig) and T. evanescens Westwood (Hymenoptera: Trichogrammatidae). The fertility life table parameters were assessed for both species at two different treatments, essential oil and ethanol as control. Although these two species were not affected similarly by the essential oil, exposure to 877 ppm (LC₀₁) in both species significantly reduced the longevity and fecundity of females, as well as the survival, developmental time, wing normality and sex ratio of their progeny. Effects of the essential oil on reproductive behavior of Trichogramma species were also investigated. Under oil treatment, despite that mate searching time increased, the percentage of mating occurrence, the duration of copulation, and sex ratio of F1 progeny declined. Given the negative effects of F. assafoetida essential oil on the two tested wasps, complementary studies are needed to develop the best management strategy for using the oil as environmentally friendly compound in combination with Trichogramma wasps against herbivorous insects.     

Do Red Deer Stags (Cervus elaphus) Use Roar Fundamental Frequency (F0) to Assess Rivals?

It is well established that in humans, male voices are disproportionately lower pitched than female voices, and recent studies suggest that this dimorphism in fundamental frequency (F0) results from both intrasexual (male competition) and intersexual (female mate choice) selection for lower pitched voices in men. However, comparative investigations indicate that sexual dimorphism in F0 is not universal in terrestrial mammals. In the highly polygynous and sexually dimorphic Scottish red deer Cervus elaphus scoticus, more successful males give sexually-selected calls (roars) with higher minimum F0s, suggesting that high, rather than low F0s advertise quality in this subspecies. While playback experiments demonstrated that oestrous females prefer higher pitched roars, the potential role of roar F0 in male competition remains untested. Here we examined the response of rutting red deer stags to playbacks of re-synthesized male roars with different median F0s. Our results show that stags’ responses (latencies and durations of attention, vocal and approach responses) were not affected by the F0 of the roar. This suggests that intrasexual selection is unlikely to strongly influence the evolution of roar F0 in Scottish red deer stags, and illustrates how the F0 of terrestrial mammal vocal sexual signals may be subject to different selection pressures across species. Further investigations on species characterized by different F0 profiles are needed to provide a comparative background for evolutionary interpretations of sex differences in mammalian vocalizations.     

Ultrasubharmonic resonance and nonlinear dynamics in the song of Oecanthus nigricornis F. Walker (Orthoptera : Gryllidae)

In the few cricket species that have been studied, there is a 1 : 1 relationship between carrier frequency and tooth-strike rate in normal song. However, for the vast majority of cricket species that relationship remains unknown. In the tree cricket, Oecanthus nigricornis F. Walker (Orthoptera : Gryllidae : Oecanthinae), the carrier frequency of the song normally equals the tooth-strike rate; rarely, the two are different and phase-locked in ultrasubharmonic ratios, such as 4 : 3 or 5 : 4. Sometimes, both frequencies are simultaneously present, giving rise to acoustic beats with 2 sharp frequency peaks related by similar ratios. The above phenomena were artificially induced in normal live singing crickets by experimental modification of one or both tegmina: beats arise when one of the tegmina vibrates at the tooth-strike frequency, while the other vibrates at the ultrasubharmonic frequency. A mathematical model is presented of the Oecanthus tegminal resonator, consisting of 2 simple coupled differential equations, one of them with a nonlinear restoring term. Integration of the model at various values of tooth-strike rate and exciting force, yields all of the observed phenomena, including normal and ultrasubharmonic output frequencies as well as beats between them. The resulting waveforms and acoustic spectra accurately reproduce those found in natural and experimental recordings.     

A Case of Fasciola hepatica Infection Mimicking Cholangiocarcinoma and ITS-1 Sequencing of the Worm

Fascioliasis is a zoonotic infection caused by Fasciola hepatica or Fasciola gigantica. We report an 87-year-old Korean male patient with postprandial abdominal pain and discomfort due to F. hepatica infection who was diagnosed and managed by endoscopic retrograde cholangiopancreatography (ERCP) with extraction of 2 worms. At his first visit to the hospital, a gallbladder stone was suspected. CT and magnetic retrograde cholangiopancreatography (MRCP) showed an intraductal mass in the common bile duct (CBD) without proximal duct dilatation. Based on radiological findings, the presumed diagnosis was intraductal cholangiocarcinoma. However, in ERCP which was performed for biliary decompression and tissue diagnosis, movable materials were detected in the CBD. Using a basket, 2 living leaf-like parasites were removed. The worms were morphologically compatible with F. hepatica. To rule out the possibility of the worms to be another morphologically close species, in particular F. gigantica, 1 specimen was processed for genetic analysis of its ITS-1 region. The results showed that the present worms were genetically identical (100%) with F. hepatica but different from F. gigantica.     

Diversity of Fusarium species and mycotoxins contaminating pineapple

Pineapple (Ananas comosus var. comosus) is an important perennial crop in tropical and subtropical areas. It may be infected by various Fusarium species, contaminating the plant material with mycotoxins. The aim of this study was to evaluate Fusarium species variability among the genotypes isolated from pineapple fruits displaying fungal infection symptoms and to evaluate their mycotoxigenic abilities. Forty-four isolates of ten Fusarium species were obtained from pineapple fruit samples: F. ananatum, F. concentricum, F. fujikuroi, F. guttiforme, F. incarnatum, F. oxysporum, F. polyphialidicum, F. proliferatum, F. temperatum and F. verticillioides. Fumonisins B₁–B₃, beauvericin (BEA) and moniliformin (MON) contents were quantified by high-performance liquid chromatography (HPLC) in pineapple fruit tissue. Fumonisins are likely the most dangerous metabolites present in fruit samples (the maximum FB₁ content was 250 μg g^?1 in pineapple skin and 20 μg ml^?1 in juice fraction). In both fractions, BEA and MON were of minor significance. FUM1 and FUM8 genes were identified in F. fujikuroi, F. proliferatum, F. temperatum and F. verticillioides. Cyclic peptide synthase gene (esyn1 homologue) from the BEA biosynthetic pathway was identified in 40 isolates of eight species. Based on the gene-specific polymerase chain reaction (PCR) assays, none of the isolates tested were found to be able to produce trichothecenes or zearalenone.     

Molecular characterization of Fasciola flukes using mitochondrial 28S rRNA gene in Naimi Saudi sheep

Fasciolosis is a parasitic disease of medical and economic importance. This retrospective study was conducted on 110 Fasciola flukes collected from livers of 14 infected Naimi sheep slaughtered at Riyadh abattoir in Saudi Arabia during winter season of 2016. Collected specimens were analyzed for their species identification on the basis of partial sequences of mitochondrial 28S rRNA gene. Results have shown the presence of both Fasciola hepatica (F. hepatica) and Fasciola gigantica (F. gigantica) species. Where Fasciola hepatica was predominate (80%). Both intra-species and interspecies genetic distance was studied and results showed that the intraspecific variability among individuals of both species i.e., F. hepatica and F. gigantica, ranging between 0 and 1% while the interspecific diversity between F. hepatica and F. gigantica was only 1%. In conclusion, mitochondrial 28S rRNA gene is a proved as a good marker in identifying Fasciola of different species. Where, the F. hepatica and F. gigantica are present in sheep breed in Riyadh region, Saudi Arabia.     

Plasticity and diversity of the phenology of dioecious Ficus species in Taiwan

While Ficus present a series of traits often associated with dioecy, the prevalence of dioecy in Ficus is atypical. In Asian floras, dioecious Ficus species generally outnumber monoecious ones. Further this is also true in relatively northerly locations for Ficus such as the island of Taiwan. Ficus are pollinated by species-specific wasps that use fig flowers as breeding sites. In dioecious fig species, pollinators develop only in the inflorescences of male fig trees. In this study, we investigated the reproductive phenology of four dioecious Ficus species with distinct ecologies in several locations in northern and southern Taiwan. The two first species (Ficus erecta and Ficus septica) were investigated in four locations. Reproductive phenology was quite different among sites, even within a single species. For example, F. erecta presented well-defined crops at the population level in its usual high-elevation habitat but continuous fig production at low elevations, especially in South Taiwan. The two other fig species (Ficus pedunculosa var. mearnsii and Ficus tinctoria subsp. swinhoei), are shrubs growing together along seashores in exposed locations on coral reef remnants. These two species presented quite different traits allowing the survival of pollinating wasp populations. Ficus pedunculosa var. mearnsii produced figs continuously so that fresh receptive figs were always available for the pollinating wasps while F. tinctoria subsp. swinhoei extended the period of receptivity of its figs, so that receptive figs that had been waiting for pollinating wasps were almost always available. In summary, dioecious figs in Taiwan showed remarkable variation in their phenology, within species among locations or among species within location. Nevertheless, despite this variation, the phenology of the trees always allowed survival of pollinating wasp populations. Dioecious figs seem to have adopted a differentiated set of strategies which result in high resilience of pollinator populations. This resilience could help explain the atypical prevalence of dioecy in Ficus.     

Gibberellin biosynthesis and gibberellin oxidase activities in Fusarium sacchari,Fusarium konzum and Fusarium subglutinans strains

Several isolates of three Fusarium species associated with the Gibberella fujikuroi species complex were characterized for their ability to synthesize gibberellins (GAs): Fusarium sacchari (mating population B), Fusarium konzum (mating population I) and Fusarium subglutinans (mating population E). Of these, F. sacchari is phylogenetically related to Fusarium fujikuroi and is grouped in the Asian clade of the complex, while F. konzum and F. subglutinans are only distantly related to Fusarium fujikuroi and belong to the American clade. Variability was found between the different F. sacchari strains tested. Five isolates (B-12756; B-1732, B-7610, B-1721 and B-1797) were active in GA biosynthesis and accumulated GA₃ in the culture fluid (2.76–28.4 μg/mL), while two others (B-3828 and B-1725) were inactive. GA₃ levels in strain B-12756 increased by 2.9 times upon complementation with ggs2 and cps-ks genes from F. fujikuroi. Of six F. konzum isolates tested, three (I-10653; I-11616; I-11893) synthesized GAs, mainly GA₁, at a low level (less than 0.1 μg/mL). Non-producing F. konzum strains contained no GA oxidase activities as found for the two F. subglutinans strains tested. These results indicate that the ability to produce GAs is present in other species of the G. fujikuroi complex beside F. fujikuroi, but might differ significantly in different isolates of the same species.     

Assessing patterns of hybridization between North Atlantic eels using diagnostic single-nucleotide polymorphisms

The two North Atlantic eel species, the European eel (Anguilla anguilla) and the American eel (Anguilla rostrata), spawn in partial sympatry in the Sargasso Sea, providing ample opportunity to interbreed. In this study, we used a RAD (Restriction site Associated DNA) sequencing approach to identify species-specific diagnostic single-nucleotide polymorphisms (SNPs) and design a low-density array that combined with screening of a diagnostic mitochondrial DNA marker. Eels from Iceland (N=159) and from the neighboring Faroe Islands (N=29) were genotyped, along with 94 larvae (49 European and 45 American eel) collected in the Sargasso Sea. Our SNP survey showed that the majority of Icelandic eels are pure European eels but there is also an important contribution of individuals of admixed ancestry (10.7%). Although most of the hybrids were identified as F1 hybrids from European eel female × American eel male crosses, backcrosses were also detected, including a first-generation backcross (F1 hybrid × pure European eel) and three individuals identified as second-generation backcrosses originating from American eel × F1 hybrid backcrosses interbreeding with pure European eels. In comparison, no hybrids were observed in the Faroe Islands, the closest bodies of land to Iceland. It is possible that hybrids show an intermediate migratory behaviour between the two parental species that ultimately brings hybrid larvae to the shores of Iceland, situated roughly halfway between the Sargasso Sea and Europe. Only two hybrids were observed among Sargasso Sea larvae, both backcrosses, but no F1 hybrids, that points to temporal variation in the occurrence of hybridization.