High FD Research Articles

Identification of Ginger (Zingiber officinale Roscoe) Volatiles and Localization of Aroma-Active Constituents by GC-Olfactometry.

For the characterization of chemical components contributing to the aroma of ginger, which could benefit the development of deep-processed ginger products, volatile extracts were isolated by a combination of direct solvent extraction-solvent-assisted flavor evaporation and static headspace analysis. Aroma-impact components were identified by gas chromatography-olfactometry-mass spectrometry, and the most potent odorants were further screened by aroma extract dilution analysis (AEDA) and static headspace dilution analysis (SHDA). The AEDA results revealed that geranial, eucalyptol, β-linalool, and bornyl acetate were the most potent odorants, exhibiting the highest flavor dilution factor (FD factor) of 2187. SHDA indicated that the predominant headspace odorants were α-pinene and eucalyptol. In addition, odorants exhibiting a high FD factor in SHDA were estimated to be potent aroma contributors in AEDA. The predominant odorants were found to be monoterpenes and sesquiterpenes, as along with their oxygenated derivatives, providing minty, lemon-like, herbal, and woody aromas. On the other hand, three highly volatile compounds detected by SHDA were not detected by AEDA, whereas 34 high-polarity, low-volatility compounds were identified only by AEDA, demonstrating the complementary natures of SHDA and AEDA and the necessity of utilizing both techniques to accurately characterize the aroma of ginger.

Determination of potential off-flavour in yeast extract

Yeast extracts is a kind of food ingredient for enhancing flavor, but some yeast extract samples had yeasty odour (off-flavour). The aim of this study was to detect key aroma compounds leading to the yeasty odour. Volatile compounds of 3 yeast extracts (with yeasty odour), FA and FB, LC were extracted by solid phase micro-extraction (SPME) and solvent assisted flavour evaporation (SAFE) respectively, and analysed by gas chromatography-olfactrometry-mass spectrometry (GC-O-MS) and aroma extract dilution analysis (AEDA) techniques. Thirty aroma-active compounds were detected, among them 4-methylphenol, 3-methylpyridine, 3-methylbutanoic acid, propanoic acid with high FD factors (FD = 125, 125, 625, 125, ≥25), were identified as the key off-flavours responsible for yeasty and their accurate quantification were done by external standard method in SIM mode. Calculation of the OAVs revealed 3-methylbutanoic acid, 3-methylpyridine, 4-methylphenol as the key odourants in the extract. For the verification of analyzed off-flavours, sensory evaluations of aroma model were conducted by eight panelists, and the result showed that aroma recombinate had the yeasty odour profile similar with the original yeast extracts.The methods were successful for the detection of off-flavors in yeast extract and the four off-compounds analyzed were mainly responsible for the yeasty flavour.

Volatile flavor constituents in the pork broth of black-pig

Pork of black-pig in China is well known for its quality and preferred by consumers. However, there is a lack of research on its flavors. By solvent assisted flavor evaporation combined with GC-MS, 104 volatile compounds in the stewed pork broth of black-pig were identified with the dominant amounts of fatty acids, alcohols, and esters. By aroma extract dilution analysis-GC-O method, 27 odor-active compounds were characterized, including 2-methyl-3-furanthiol, 3-(methylthio)propanal, 2-furfurylthiol, γ-decalactone, nonanal, (E)-2-nonenal, and (E,E)-2,4-decadienal that had high FD factors. Compared to the common white-pig, the aroma compounds in both pork broths were almost the same, but the aroma profile of potent odorants for the black-pig pork broth showed less fatty and more roasted notes, which were partially attributed to the higher monounsaturated fatty acids and lower polyunsaturated fatty acids in meat. With aid of authentic chemicals and selected reaction monitoring mode of GC-MS/MS, 19 aroma compounds were quantitated.

Aroma Stability of Lemon-Flavored Hard Iced Tea Assessed by Chirality and Aroma Extract Dilution Analysis.

The aroma of fresh and aged lemon-flavored hard tea was investigated by aroma extract dilution analysis (AEDA), quantitative comparison, and two-dimensional chirality analysis. Aroma extract dilution analysis of fresh hard tea samples showed 3-methylbutanal, isoamyl alcohol, β-damascenone, β-ionone, 2-phenylethanol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, and vanillin could be the most important aroma contributors to the hard tea due to their high FD values. The analysis of the aged hard tea samples did not reveal new compound formation during storage; however, compared with fresh samples, the flavor dilution value changed substantially in the aged samples. Both AEDA and quantitative analysis demonstrated that β-damascenone increased substantially in aged samples, whereas terpene aldehydes decreased substantially after storage. In addition, the FD value of linalool decreased dramatically in aged samples. Two-dimensional GC-MS chirality analysis revealed the FD value decrease of linalool in aged samples was largely due to the transformation of (R)-linalool to (S)-linalool, which has a higher sensory threshold.

Spatiotemporal changes in flying insect abundance and their functional diversity as a function of distance to natural habitats in a mass flowering crop

To meet the dietary requirements of a burgeoning human population, the demand for animal-dependent crops continues to grow. To meet the demand, intensive farming practices are used. The gains in food production associated with agricultural intensification may be offset by its detrimental effects on pollinator populations through natural habitat fragmentation and pesticide use. Abundance and species richness of pollinators have been found to decrease with increasing distance to natural habitat in agroecosystems, reducing crop yields. A key aspect of crop pollination lies in the diversity of functional traits (functional diversity, FD) of flower-visitor communities within crop fields. Higher FD allows improved pollination success through complementarity between flower-visitors’ morphology, phenology and behaviour. Many studies reported negative effects of increasing distance to natural habitats on the abundance and richness of flower-visitor communities, but the link between FD and natural habitat isolation is less well understood. Also, a more complete understanding of the functional traits of flower-visitor communities within crops should consider potential variations through time. Differences in resources availability between seasons are important in tropical areas and could modify ecological responses of flower-visitor communities to isolation. In this study, we surveyed the Hymenoptera and Diptera communities within mango orchards of South Africa using pan traps at 100m, 200m and at the maximal distance possible from any natural habitat. We measured the response of insect abundance, wing span and body size as well as functional diversity to habitat isolation during mango flowering (dry season), and during the wet season (after mango fruit harvest). Flying insect abundance decreased with increasing distance to natural habitat during mango flowering, but no effect was detected during the wet season. FD of flying insects declined with increasing distance to natural habitat in both sampling periods. Insects captured during mango flowering were smaller but had higher wing length/body length ratios than those caught during the wet season. This study highlights that mango orchards are more inhospitable for flying insects during mango flowering. This effect might be due to low palatability of mango flowers, or pesticide use in mango fields. In order to maintain a high FD of flower-visiting species, and reduce the detrimental effects of habitat isolation to ultimately ensure better crop pollination, we propose establishment of patches of resource-rich habitats combined with judicious use of pesticides within orchards.

Opposing Patterns of Seasonal Change in Functional and Phylogenetic Diversity of Tadpole Assemblages.

Assemblages that are exposed to recurring temporal environmental changes can show changes in their ecological properties. These can be expressed by differences in diversity and assembly rules. Both can be identified using two measures of diversity: functional (FD) and phylogenetic diversity (PD). Frog communities are understudied in this regard, especially during the tadpole life stage. We utilised tadpole assemblages from Madagascan rainforest streams to test predictions of seasonal changes on diversity and assemblage composition and on diversity measures. From the warm-wet to the cool-dry season, species richness (SR) of tadpole assemblages decreased. Also FD and PD decreased, but FD less and PD more than expected by chance. During the dry season, tadpole assemblages were characterised by functional redundancy (among assemblages—with increasing SR), high FD (compared to a null model), and low PD (phylogenetic clustering; compared to a null model). Although mutually contradictory at first glance, these results indicate competition as tadpole community assembly driving force. This is true during the limiting cool-dry season but not during the more suitable warm-wet season. We thereby show that assembly rules can strongly depend on season, that comparing FD and PD can reveal such forces, that FD and PD are not interchangeable, and that conclusions on assembly rules based on FD alone are critical.

Determination of aroma compounds in pork broth produced by different processing methods

AbstractThe aroma‐active compounds in pork broth cooked by different processing methods were extracted by solid phase micro extraction (SPME) and solvent‐assisted flavour evaporation (SAFE) and analysed by gas chromatography‐olfactometry‐mass spectrometry (GC‐O‐MS). In total, 78 different aroma‐active compounds were tentatively identified in pork broth. Among them, 12 compounds such as ethyl acetate, 3‐(methylthio) propanal, hexanal, 2‐butanone, dimethyl disulfide and dimethyl trisulfide were tentatively identified as predominant aroma‐active compounds in pork broth, according to their high FD value. According to sensory evaluation, the main characteristic flavour of the four samples was the intensely meaty aroma. By investigating the four kinds of pork broth processed by different methods, the broth cooked at 96 °C with air circulation was found to possess stronger meaty aroma and best overall sensory. Copyright © 2016 John Wiley & Sons, Ltd.

Imaging Tumor Targeted Delivery using FRET in vivo

Our goal is to develop <em style=”mso‐bidi‐font‐style: normal;”>in vivo non‐invasive optical imaging assays for optimization of anti‐cancer drug targeted therapy. We have established a fluorescence lifetime Förster Resonance Energy Transfer (FL‐FRET) non‐invasive whole‐body <em style=”mso‐bidi‐font‐style: normal;”>in vivo tomographic imaging technique that can discriminate bound and internalized near‐infrared (NIR)‐labeled transferrin (Tfn) from free, soluble NIR‐Tfn. This FRET assay exploits the homodimeric nature of transferrin receptor (TFR) that binds two molecules of Tfn in close proximity to determine dimerization and internalization of TFR‐Tfn complexes into cancer cells. The Tfn FRET assay has been validated <em style=”mso‐bidi‐font‐style: normal;”>in vitro by visible and NIR FRET microscopy. FL‐FRET imaging <em style=”mso‐bidi‐font‐style: normal;”>in vivo has been used to measure the internalization of tail‐vein injected NIR‐Tfn into human breast T47D tumor xenografts in live nude mice. Quantification of FRET donor % (FD%) in T47D tumor xenografts, indicates a higher proportion of FD% with increasing acceptor:donor ratio, demonstrating tumor uptake of NIR‐Tfn. Furthermore, relative high FD% for holo‐Tfn (iron‐loaded) compared to that of apo‐Tfn (iron‐depleted) demonstrates specific TFR‐mediated uptake of holo‐Tfn by T47D tumor xenografts. In conclusion, we have successfully demonstrated the quantitative receptor‐mediated uptake of Tfn into human breast tumors <em style=“mso‐bidi‐font‐style: normal;”>in vivo using a novel non‐invasive NIR FL‐FRET tomographic imaging assay.

Conservation along a hotspot rim: spiders in Brazilian coastal restingas

Protected areas are essential for the maintenance of biodiversity, but defining criteria for prioritizing areas to conserve is not an easy task. In general, selection has been based on species richness and endemism of plants and vertebrates; however, these do not necessarily match invertebrate data, hence the need of using other groups in conservation prioritization. Moreover, species richness represents one of several biodiversity facets and does not subsume other facets such as functional and phylogenetic diversity. Restingas are coastal ecosystems within the Atlantic Forest biome, one of the World’s biodiversity hotspots. We investigated whether there is congruence between three different spider biodiversity facets: functional (FD, the variety of functional traits of species), phylogenetic (PD, the evolutionary distinctness of species), and taxonomic (TD, the number and the relative abundance of species), and whether currently protected restingas are effective in protecting these facets. We studied vegetation-living spider communities in 11 restingas along 2,000 km of the Brazilian coast. We found that no value of any biodiversity facet was higher in protected restingas compared with unprotected ones. We demonstrated low congruence between the three biodiversity facets, so that the use of TD as a surrogate of other facets is unwarranted. Whilst some protected restingas hold high values of spider TD, other still unprotected areas present high PD or FD. This result suggests that conservation efforts should be extended to every remaining restinga because they are unique sites to at least one spider biodiversity facet. In particular, we recommend three unprotected restingas as high priorities in future conservation plans based on spider diversity, which corroborate findings for plants and vertebrates in the same sites.

Pyroelectric properties of rare-earth calcium oxyborate crystals: ReCa<sub>4</sub>O(BO<sub>3</sub>)<sub>3</sub> (Re: Y, Gd, Nd, and Pr)

Pyroelectric properties of the monoclinic ReCa4O(BO3)3 (ReCOB, where Re is rare earth: Y, Gd, Nd, and Pr) single crystals were investigated by the charge integration method in the temperature range of 20°C to 180°C. The two independent pyroelectric coefficients p1 and p3 were measured and their temperature-dependent properties were studied; the pyroelectric p1 was found to be negative and decrease with increasing temperature, varying from -59.3, -64.2, -65.5, and -59.5 μC/(m2·°C) at 30°C to -52.9, -53.3, -46.6, and -50.5 μC/(m2·°C) at 180°C for YCOB, GdCOB, NdCOB, and PrCOB, respectively, whereas the positive coefficient p3 was observed to decrease from 11.6, 13.6, 23.5, and 31.0 μC/(m2·°C) at 30°C to 2.5, 7.1, 4.9, and 10.1 μC/(m2·°C) at 180°C, respectively. In addition, the ReCOB crystals were found to possess relatively high detectivity Fd, being 7.6 to 11.4 x 10-5 Pa-1/2 at 30°C, approximately two times that of commercial triglycine sulfate (TGS) and LiTaO3 crystals, with minimal variations up to 180°C, indicating the potential for use in thermal imaging applications.

Discovery of Holocene millennial climate cycles in the Asian continental interior: Has the sun been governing the continental climate?

We conducted a high-resolution study of a unique Holocene sequence of wind-blown sediments and buried soils in Southern Siberia, far from marine environment influences. This was accomplished in order to assess the difference between North Atlantic marine and in-land climate variations. Relative wind strength was determined by grain size analyses of different stratigraphic units. Petromagnetic measurements were performed to provide a proxy for the relative extent of pedogenesis. An age model for the sections was built using the radiocarbon dating method. The windy periods are associated with the absence of soil formation and relatively low values of frequency dependence of magnetic susceptibility (FD), which appeared to be a valuable quantitative marker of pedogenic activity. These events correspond to colder intervals which registered reduced solar modulation and sun spot number. Events, where wind strength was lower, are characterized by soil formation with high FD values. Spectral analysis of our results demonstrates periodic changes of 1500, 1000 and 500years of relatively warm and cold intervals during the Holocene of Siberia. We presume that the 1000 and 500year climatic cycles are driven by increased solar insolation reaching the Earth surface and amplified by other still controversial mechanisms. The 1500year cycle associated with the North Atlantic circulation appears only in the Late Holocene. Three time periods — 8400–9300years BP, 3600–5100years BP, and the last ~250years BP — correspond to both the highest sun spot number and the most developed soil horizons in the studied sections.

Identification of key aroma compounds from bitter orange (Citrus aurantium L.) products: essential oil and macerate–distillate extract

ABSTRACTThe volatile compounds of bitter orange (Citrus aurantium L.) products, essential oil (EO) and the heart cut (HC) of the distillate were detected and quantified using gas chromatography (GC) coupled with a mass spectrometer and flame ionization detector. The flavour compounds were characterized using GC–olfactometry by nine trained panellists by the frequency of detection method. In total, 53 molecules were detected in the EO and 40 in the HC. The EO was characterized by 19 major odour compounds (frequency of detection from 6/9 to 9/9) with different aromatic notes among which α‐pinene (floral), octanal (green), limonene (citrus), linalool (floral), α‐terpineol (indeterminate: ‘ND’, green), linalyl acetate (floral), (E,E) or (E,Z)‐2,4‐decadienal (frying), dodecanal (ND), caryophyllene (green) and an unknown compound (IT = 1678, plastic note). The HC presented a complex mixture of several molecules in low concentrations, which characterize the bitter orange flavour. The HC was characterized by seven high FD odour compounds, three of them (myrcene, α‐phellandrene, and limonene) with citrus and mint aromatic notes, and the other four ((Z)‐linalool oxide, α‐terpinolene, linalool and neral) with floral notes. The comparison of these two products brought to light that the overall process of maceration/distillation could induce the loss of 15 strong odours previously found in simple essential oil and characterized by plastic and metal notes. These results show that macerating–distilling bitter orange peels and EO makes it possible to select the most pleasant odour compounds while eliminating some off‐odours present in the EO. This is the first time that the characterization of odour‐active compounds has been carried out on bitter orange products. This valuable information could help for further investigation on process/product optimization. Copyright © 2011 John Wiley & Sons, Ltd.

Reconstitution of the Flavor Signature of Dornfelder Red Wine on the Basis of the Natural Concentrations of Its Key Aroma and Taste Compounds

By application of aroma extract dilution analysis (AEDA) on the volatile fraction isolated from a Dornfelder red wine, 31 odor-active compounds were identified by means of HRGC-MS and comparison with reference compounds. A total of 27 odorants, judged with high FD factors by means of AEDA, was quantitated by means of stable isotope dilution assays, and acetaldehyde was determined enzymatically. In addition, 36 taste-active compounds were analyzed by means of HPLC-UV, HPLC-MS/MS, and ion chromatography. The quantitative data obtained for the identified aroma and taste compounds enabled for the first time the reconstruction of the overall flavor of the red wine. Sensory evaluation of both the aroma and taste profiles of the authentic red wine and the recombinate revealed that Dornfelder red wine was closely mimicked. Moreover, it was demonstrated that the high molecular weight fraction of red wine is essential for its astringent taste impression. By comparison of the overall odor of the aroma recombinate in ethanol with that of the total flavor recombinate containing all tastants, it was shown for the first time that the nonvolatile tastants had a strong influence on the intensity of certain aroma qualities.

Luminescence properties of lanthanide doped alkaline earth chlorides under (V)UV and X-ray excitation

The photoluminescence and radioluminescence of Ce 3+, Pr 3+ and Nd 3+ in SrCl 2 and BaCl 2 are reported and discussed in relation to application as a (fast) scintillator material. The Ce 3+ doped materials exhibit the typical fast cerium d– f emission (358, 382 nm in SrCl 2 and 350, 375 nm in BaCl 2) both under synchrotron and ionizing radiation excitations. A weak afterglow is observed. For Pr 3+ a very fast d– f emission is observed in SrCl 2 (250, 263, 300 and 328 nm, τ = 13 ns) and BaCl 2 (260, 288 and 315 nm, τ = 10 ns), but only under direct f– d excitation. No d– f luminescence is observed for Pr 3+ under X-ray excitation. The absence of d– f emission is explained by the energy of the host lattice emission which is too low for energy transfer to the high energy fd states of Pr 3+ (230 nm in SrCl 2 and 235 nm in BaCl 2). The neodymium doped chlorides do not show d– f luminescence.

Landscape dynamics at the public–private interface: A case study in Colorado

The Rocky Mountain West is experiencing rapid land use change in the form of residential development. Public land managers, like the U.S. Forest Service, Bureau of Land Management, and National Park Service are increasingly concerned with ecological and management implications of private land use adjacent to public lands. Using fine-grain land use data, collected from high resolution aerial photographs, we quantify human land use composition, patterns, and trends at the interface of public and private land in the Southern Rocky Mountain Ecoregion (SRE) of Colorado. We developed two metrics for assessing land use impacts. The first quantifies the amount of land cover modified (HM c) by human land use and the second estimates the amount of wildlife habitat that is functionally modified (HM fd). In 2005, we estimate that human land use modifies 8% of the total land cover in the Colorado SRE and that 13% of the study area was functionally modified. Agriculture had the greatest impact in terms of area of modified land cover (282,305 ha). Residential (exurban) land use had a smaller footprint (HM c) but the close proximity to public lands, dispersed spatial pattern (high HM fd), and rapid increase in rural and exurban housing density observed in the SRE have important implications. This research demonstrates how fine scale land cover data can be used to examine land use pattern and composition as well as track land use change.

Identification of Characteristic Aroma Components of Thai Fried Chili Paste

Three forms of Thai fried chili pastes (CP) were prepared, consisting of an unheated CP (UH-CP), a CP heated at 100 degrees C for 25 min (H25-CP, typical product), and a CP excessively heated for 50 min (H50-CP). The potent odorants in the CPs were investigated by two gas chromatography-olfactometry methods: dynamic headspace dilution analysis (DHDA) and aroma extract dilution analysis (AEDA). DHDA revealed that the predominant odorants in heated CPs were mainly sulfur-containing compounds, followed by lipid-derived compounds, Strecker aldehydes, and Maillard reaction products. Dimethyl sulfide, allyl mercaptan, 2- (or 3-) methylbutanal, ally methyl sulfide, 2,3-butanedione, 3,3'-thiobis(1-propene), and methyl propyl disulfide were among the most potent headspace odorants detected by DHDA. By AEDA, 2-vinyl-4 H-1,3-dithiin and diallyl trisulfide had the highest FD factors in H25-CP. On the basis of their high FD factors by both GCO methods, the predominant odorants in H25-CP were 3-vinyl-4 H-1,2-dithiin, allyl methyl disulfide, and allyl methyl trisulfide. Furthermore, dimethyl trisulfide and diallyl disulfide had the highest odor activity values in H25-CP, suggesting that these were also potent odorants in CP. In addition, methional, 3-methylbutanoic acid, 4-hydroxy-2,5-dimethyl-3-(2 H)-furanone, and 3-hydroxy-4,5-dimethyl-2( 5H)-furanone (sotolon) were indicated as potent thermally derived odorants of H25-CP.

Effect of Cysteine and Cystine Addition on Sensory Profile and Potent Odorants of Extruded Potato Snacks

Aromas generated in extruded potato snacks without and with addition of 0.25, 0.5, and 1% (w/w) of flavor precursors, cysteine and cystine, were compared and evaluated by descriptive sensory profiling. The results showed that high addition of cysteine (0.5 and 1%) resulted in the formation of undesirable odor and taste described as mercaptanic/sulfur, onion-like, and bitter; on the contrary, addition of cystine even at high concentration gave product with pleasant odor and taste, slightly changed into breadlike notes. GC/O analysis showed cysteine to be a much more reactive flavor precursor than cystine, stimulating formation of 12 compounds with garlic, sulfury, burnt, pungent/beer, cabbage/mold, meatlike, roasted, and popcorn odor notes. Further analysis performed by the AEDA technique identified 2-methyl-3-furanthiol (FD 2048) as a most potent odorant of extruded potato snacks with 1% addition of cysteine. Other identified compounds with high FD were butanal, 3-methyl-2-butenethiol, 2-methylthiazole, methional, 2-acetyl-1-pyrroline, and 3-hydroxy-4,5-dimethyl-2(5H)-furanone. In the case of cystine addition (1%) the highest FD factors were calculated for butanal, 2-acetyl-1-pyrroline, benzenemethanethiol, methional, phenylacetaldehyde, dimethyltrisulfide, 1-octen-3-ol, 1,5-octadien-3-one, and 2-acetylpyrazine.

Nearby Debris Disk Systems with High Fractional Luminosity Reconsidered

By searching the IRAS and ISO databases we compiled a list of 60 debris disks which exhibit the highest fractional luminosity values (fd>10^-4) in the vicinity of the Sun (d 5x10^-4 are younger than 100Myr. The distribution of the disks in the fractional luminosity versus age diagram indicates that (1) the number of old systems with high fd is lower than was claimed before; (2) there exist many relatively young disks of moderate fractional luminosity; and (3) comparing the observations with a current theoretical model of debris disk evolution a general good agreement could be found.

High-frequency calling in Eneopterinae crickets (Orthoptera, Grylloidea, Eneopteridae): adaptive radiation revealed by phylogenetic analysis

The dominant frequency (Fd) of the cricket calling song commonly ranges from 2 to 8 kHz because of physical constraints due to small size and stridulum functioning. However some Eneopterinae crickets are known to call with Fds of 10–15 kHz, and one species (Eneoptera guyanensis) produces a modulated call with both a low and a high Fd. We studied Fd evolution with respect to phylogeny in the whole Eneopterinae subfamily to reconstruct its pattern of transformation. The phylogenetic pattern resulting from the analysis showed that Fd is relatively stable through the whole clade: the Fd ancestral state (3–7.9 kHz) has been modified only once, with the occurrence of a high Fd in the clade [Cardiodactylus (Lebinthus–Agnotecous)]: high Fd replaced low Fd, resulting in high-frequency calling songs. In E. guyanensis, the pattern of frequency change is different: a high Fd component has been added to the low ancestral Fd, resulting in frequency modulation. Investigation of cladogenesis rate indicated that the onset of high Fd in [Cardiodactylus (Lebinthus–Agnotecous)] was accompanied by a high cladogenesis rate, supporting a hypothesis of adaptive radiation for high-frequency calling (phylogeny criterion of adaptation). High frequencies are particularly problematic for long-range communication, especially for forest-living species, because of the increase of excess attenuation with frequency. The effectiveness of high-frequency calling is discussed in the clade [Cardiodactylus (Lebinthus–Agnotecous)] in relation to the behavioural ecology of the species. © 2004 The Linnean Society of London, Biological Journal of the Linnean Society, 2004, 83, 577–584.

Evolution of acoustic communication in crickets: phylogeny of Eneopterinae reveals an adaptive radiation involving high-frequency calling (Orthoptera, Grylloidea, Eneopteridae).

Evolution of dominant frequencies in songs of Eneopterinae crickets was studied with respect to phylogeny. Two characters are optimized on the tree: the first describes the frequency resulting from the vibration of the harp (Fda), and the second is due to the vibration of other tegminal areas (Fdb). Fda was found to be relatively stable through the subfamily. Its low ancestral state is replaced by a high Fda only once, resulting in high-frequency calling in [Cardiodactylus (Lebinthus-Agnotecous)]. A high Fdb component is added to the low ancestral Fda in Eneoptera guyanensis, resulting in frequency modulation. The onset of high Fd in this first subclade is accompanied by a high cladogenesis rate, which supports a hypothesis of adaptive radiation for high frequencies. The effectiveness of high-frequency calling is discussed in relation to the species behavior ecology.