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We report the first multi-differential measurements of strange hadrons of K −, φ and − yields as well as the ratios of φ/K − and φ/− in Au+Au collisions at √sNN = 3 GeV with the STAR experiment fixed target configuration at RHIC. The φ mesons and − hyperons are measured through hadronic decay channels, φ → K + K − and Ξ− → Λπ−. Collision centrality and rapidity dependence of the transverse momentum spectra for these strange hadrons are presented. The 4π yields and ratios are compared to thermal model and hadronic transport model predictions. At this collision energy, thermal model with grand canonical ensemble (GCE) under-predicts the φ/K − and φ/− ratios while the result of canonical ensemble (CE) calculations reproduce φ/K −, with the correlation length rc ∼ 2.7 fm, and φ/−, rc ∼ 4.2 fm, for the 0-10% central collisions. Hadronic transport models including high mass resonance decays could also describe the ratios. While thermal calculations with GCE work well for strangeness production in high energy collisions, the change to CE at 3 GeV implies a rather different medium property at high baryon density.
Measurement of inclusive J/ψ polarization in p + p collisions at √s=200 GeV by the STAR experiment
(2020)
We report on new measurements of inclusive 𝐽/𝜓 polarization at midrapidity in 𝑝+𝑝 collisions at √𝑠=200 GeV by the STAR experiment at the Relativistic Heavy Ion Collider. The polarization parameters, 𝜆𝜃, 𝜆𝜙, and 𝜆𝜃𝜙, are measured as a function of transverse momentum (𝑝T) in both the helicity and Collins-Soper (CS) reference frames within 𝑝T<10 GeV/𝑐. Except for 𝜆𝜃 in the CS frame at the highest measured 𝑝T, all three polarization parameters are consistent with 0 in both reference frames without any strong 𝑝T dependence. Several model calculations are compared with data, and the one using the Color Glass Condensate effective field theory coupled with nonrelativistic QCD gives the best overall description of the experimental results, even though other models cannot be ruled out due to experimental uncertainties.
Measurement of inclusive charged-particle jet production in Au + Au collisions at √sNN=200 GeV
(2020)
The STAR Collaboration at the Relativistic Heavy Ion Collider reports the first measurement of inclusive jet production in peripheral and central Au+Au collisions at √𝑠𝑁𝑁=200 GeV. Jets are reconstructed with the anti-𝑘𝑇 algorithm using charged tracks with pseudorapidity |𝜂|<1.0 and transverse momentum 0.2<𝑝ch
𝑇,jet<30 GeV/𝑐, with jet resolution parameter 𝑅=0.2, 0.3, and 0.4. The large background yield uncorrelated with the jet signal is observed to be dominated by statistical phase space, consistent with a previous coincidence measurement. This background is suppressed by requiring a high-transverse-momentum (high-𝑝𝑇) leading hadron in accepted jet candidates. The bias imposed by this requirement is assessed, and the 𝑝𝑇 region in which the bias is small is identified. Inclusive charged-particle jet distributions are reported in peripheral and central Au+Au collisions for 5<𝑝ch
𝑇,jet<25 GeV/𝑐 and 5<𝑝ch
𝑇,jet<30 GeV/𝑐, respectively. The charged-particle jet inclusive yield is suppressed for central Au+Au collisions, compared to both the peripheral Au+Au yield from this measurement and to the 𝑝𝑝 yield calculated using the PYTHIA event generator. The magnitude of the suppression is consistent with that of inclusive hadron production at high 𝑝𝑇 and that of semi-inclusive recoil jet yield when expressed in terms of energy loss due to medium-induced energy transport. Comparison of inclusive charged-particle jet yields for different values of 𝑅 exhibits no significant evidence for medium-induced broadening of the transverse jet profile for 𝑅 <0.4 in central Au+Au collisions. The measured distributions are consistent with theoretical model calculations that incorporate jet quenching.
Measurement of inclusive charged-particle jet production in Au+Au collisions at √sNN = 200 GeV
(2021)
The STAR Collaboration at the Relativistic Heavy Ion Collider reports the first measurement of inclusive jet production in peripheral and central Au+Au collisions at sNN−−−−√=200 GeV. Jets are reconstructed with the anti-kT algorithm using charged tracks with pseudorapidity |η|<1.0 and transverse momentum 0.2<pchT,jet<30 GeV/c, with jet resolution parameter R=0.2, 0.3, and 0.4. The large background yield uncorrelated with the jet signal is observed to be dominated by statistical phase space, consistent with a previous coincidence measurement. This background is suppressed by requiring a high-transverse-momentum (high-pT) leading hadron in accepted jet candidates. The bias imposed by this requirement is assessed, and the pT region in which the bias is small is identified. Inclusive charged-particle jet distributions are reported in peripheral and central Au+Au collisions for 5<pchT,jet<25 GeV/c and 5<pchT,jet<30 GeV/c, respectively. The charged-particle jet inclusive yield is suppressed for central Au+Au collisions, compared to both the peripheral Au+Au yield from this measurement and to the pp yield calculated using the PYTHIA event generator. The magnitude of the suppression is consistent with that of inclusive hadron production at high pT, and that of semi-inclusive recoil jet yield when expressed in terms of energy loss due to medium-induced energy transport. Comparison of inclusive charged-particle jet yields for different values of R exhibits no significant evidence for medium-induced broadening of the transverse jet profile for R<0.4 in central Au+Au collisions. The measured distributions are consistent with theoretical model calculations that incorporate jet quenching.
We report on the measurement of the Central Exclusive Production of charged particle pairs h+h− (h = π, K, p) with the STAR detector at RHIC in proton-proton collisions at √s = 200 GeV. The charged particle pairs produced in the reaction pp → p′ + h+h− + p′ are reconstructed from the tracks in the central detector and identified using the specific energy loss and the time of flight method, while the forward-scattered protons are measured in the Roman Pot system. Exclusivity of the event is guaranteed by requiring the transverse momentum balance of all four final-state particles. Differential cross sections are measured as functions of observables related to the central hadronic final state and to the forward-scattered protons. They are measured in a fiducial region corresponding to the acceptance of the STAR detector and determined by the central particles’ transverse momenta and pseudorapidities as well as by the forward-scattered protons’ momenta. This fiducial region roughly corresponds to the square of the four-momentum transfers at the proton vertices in the range 0.04 GeV2 < −t1, −t2 < 0.2 GeV2, invariant masses of the charged particle pairs up to a few GeV and pseudorapidities of the centrally-produced hadrons in the range |η| < 0.7. The measured cross sections are compared to phenomenological predictions based on the Double Pomeron Exchange (DPE) model. Structures observed in the mass spectra of π+π− and K+K− pairs are consistent with the DPE model, while angular distributions of pions suggest a dominant spin-0 contribution to π+π− production. For π+π− production, the fiducial cross section is extrapolated to the Lorentz-invariant region, which allows decomposition of the invariant mass spectrum into continuum and resonant contributions. The extrapolated cross section is well described by the continuum production and at least three resonances, the f0(980), f2(1270) and f0(1500), with a possible small contribution from the f0(1370). Fits to the extrapolated differential cross section as a function of t1 and t2 enable extraction of the exponential slope parameters in several bins of the invariant mass of π+π− pairs. These parameters are sensitive to the size of the interaction region.
We report measurements of the longitudinal double-spin asymmetry, ALL, for inclusive jet and dijet production in polarized proton-proton collisions at midrapidity and center-of-mass energy s√ = 510 GeV, using the high luminosity data sample collected by the STAR experiment in 2013. These measurements complement and improve the precision of previous STAR measurements at the same center-of-mass energy that probe the polarized gluon distribution function at partonic momentum fraction 0.015 ≲x≲ 0.25. The dijet asymmetries are separated into four jet-pair topologies, which provide further constraints on the x dependence of the polarized gluon distribution function. These measurements are in agreement with previous STAR measurements and with predictions from current next-to-leading order global analyses. They provide more precise data at low dijet invariant mass that will better constraint the shape of the polarized gluon distribution function of the proton.
We present measurements of the differential cross sections of inclusive J/ψ meson production as a function of transverse momentum (pJ/ψT) using the μ+μ− and e+e− decay channels in proton+proton collisions at center-of-mass energies of 510 and 500 GeV, respectively, recorded by the STAR detector at the Relativistic Heavy Ion Collider. The measurement from the μ+μ− channel is for 0 <pJ/ψT< 9 GeV/c and rapidity range |yJ/ψ|< 0.4, and that from the e+e− channel is for 4 <pJ/ψT< 20 GeV/c and |yJ/ψ|< 1.0. The ψ(2S) to J/ψ ratio is also measured for 4 <pmesonT< 12 GeV/c through the e+e− decay channel. Model calculations, which incorporate different approaches toward the J/ψ production mechanism, are compared with experimental results and show reasonable agreement within uncertainties.
We report on the first measurements of J/ψ production at very low transverse momentum (pT< 0.2 GeV/c) in hadronic Au+Au collisions at √sNN = 200 GeV and U+U collisions at √sNN = 193 GeV. Remarkably, the inferred nuclear modification factor of J/ψ at mid-rapidity in Au+Au (U+U) collisions reaches about 24 (52) for pT< 0.05 GeV/c in the 60-80% collision centrality class. This noteworthy enhancement cannot be explained by hadronic production accompanied by cold and hot medium effects. In addition, the dN/dt distribution of J/ψ for the very low pT range is presented for the first time. The distribution is consistent with that expected from the Au nucleus and shows a hint of interference. Comparison of the measurements to theoretical calculations of coherent production shows that the excess yield can be described reasonably well and reveals a partial disruption of coherent production in semi-central collisions, perhaps due to the violent hadronic interactions. Incorporating theoretical calculations, the results strongly suggest that the dramatic enhancement of J/ψ yield observed at extremely low pT originates from coherent photon-nucleus interactions. In particular, coherently produced J/ψ's in violent hadronic collisions may provide a novel probe of the quark-gluon-plasma.
We report on the first measurements of J/ψ production at very low transverse momentum (pT< 0.2 GeV/c) in hadronic Au+Au collisions at √sNN = 200 GeV and U+U collisions at √sNN = 193 GeV. Remarkably, the inferred nuclear modification factor of J/ψ at mid-rapidity in Au+Au (U+U) collisions reaches about 24 (52) for pT< 0.05 GeV/c in the 60-80% collision centrality class. This noteworthy enhancement cannot be explained by hadronic production accompanied by cold and hot medium effects. In addition, the dN/dt distribution of J/ψ for the very low pT range is presented for the first time. The distribution is consistent with that expected from the Au nucleus and shows a hint of interference. Comparison of the measurements to theoretical calculations of coherent production shows that the excess yield can be described reasonably well and reveals a partial disruption of coherent production in semi-central collisions, perhaps due to the violent hadronic interactions. Incorporating theoretical calculations, the results strongly suggest that the dramatic enhancement of J/ψ yield observed at extremely low pT originates from coherent photon-nucleus interactions. In particular, coherently produced J/ψ's in violent hadronic collisions may provide a novel probe of the quark-gluon-plasma.
Investigation of the linear and mode-coupled flow harmonics in Au+Au collisions at √sNN = 200 GeV
(2020)
Flow harmonics (vn) of the Fourier expansion for the azimuthal distributions of hadrons are commonly employed to quantify the azimuthal anisotropy of particle production relative to the collision symmetry planes. While lower order Fourier coefficients (v2 and v3) are more directly related to the corresponding eccentricities of the initial state, the higher-order flow harmonics (vn>3) can be induced by a modecoupled response to the lower-order anisotropies, in addition to a linear response to the same-order anisotropies. These higher-order flow harmonics and their linear and mode-coupled contributions can be used to more precisely constrain the initial conditions and the transport properties of the medium in theoretical models. The multiparticle azimuthal cumulant method is used to measure the linear and mode-coupled contributions in the higher-order anisotropic flow, the mode-coupled response coefficients, and the correlations of the event plane angles for charged particles as functions of centrality and transverse momentum in Au+Au collisions at nucleon-nucleon center-of-mass energy √sN N= 200 GeV. The results are compared to similar LHC measurements as well as to several viscous hydrodynamic calculations with varying initial conditions.
Measurement of groomed jet substructure observables in p+p collisions at √s = 200 GeV with STAR
(2020)
In this letter, measurements of the shared momentum fraction (zg) and the groomed jet radius (Rg), as defined in the SoftDrop algorithm, are reported in p+p collisions at √s = 200 GeV collected by the STAR experiment. These substructure observables are differentially measured for jets of varying resolution parameters from R = 0.2 − 0.6 in the transverse momentum range 15 < pT,jet < 60 GeV/c. These studies show that, in the pT,jet range accessible at √s = 200 GeV and with increasing jet resolution parameter and jet transverse momentum, the zg distribution asymptotically converges to the DGLAP splitting kernel for a quark radiating a gluon. The groomed jet radius measurements reflect a momentum-dependent narrowing of the jet structure for jets of a given resolution parameter, i.e., the larger the pT,jet, the narrower the first splitting. For the first time, these fully corrected measurements are compared to Monte Carlo generators with leading order QCD matrix elements and leading log in the parton shower, and to state-of-the-art theoretical calculations at next-to-leading-log accuracy. We observe that PYTHIA 6 with parameters tuned to reproduce RHIC measurements is able to quantitatively describe data, whereas PYTHIA 8 and HERWIG 7, tuned to reproduce LHC data, are unable to provide a simultaneous description of both zg and Rg, resulting in opportunities for fine parameter tuning of these models for p+p collisions at RHIC energies. We also find that the theoretical calculations without non-perturbative corrections are able to qualitatively describe the trend in data for jets of large resolution parameters at high pT,jet, but fail at small jet resolution parameters and low jet transverse momenta.
We report results on the total and elastic cross sections in proton-proton collisions at √s = 200 GeV obtained with the Roman Pot setup of the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The elastic differential cross section was measured in the squared four-momentum transfer range 0.045 ≤ −t ≤ 0.135 GeV2. The value of the exponential slope parameter B of the elastic differential cross section dσ/dt ∼ e−Bt in the measured −t range was found to be B = 14.32 ± 0.09(stat.)+0.13 −0.28(syst.) GeV−2. The total cross section σtot, obtained from extrapolation of the dσ/dt to the optical point at −t = 0, is σtot = 54.67 ± 0.21(stat.)+1.28 −1.38(syst.) mb. We also present the values of the elastic cross section σel = 10.85 ± 0.03(stat.)+0..49 −0.41(syst.) mb, the elastic cross section integrated within the STAR t-range σ det el = 4.05 ± 0.01(stat.)+0.18−0.17(syst.) mb, and the inelastic cross section σinel = 43.82 ± 0.21(stat.)+1.37−1.44(syst.) mb. The results are compared with the world data
Quark interactions with topological gluon configurations can induce chirality imbalance and local parity violation in quantum chromodynamics. This can lead to electric charge separation along the strong magnetic field in relativistic heavy-ion collisions – the chiral magnetic effect (CME). We report measurements by the STAR collaboration of a CME-sensitive observable in p + Au and d + Au collisions at 200 GeV, where the CME is not expected, using charge-dependent pair correlations relative to a third particle. We observe strong charge-dependent correlations similar to those measured in heavy-ion collisions. This bears important implications for the interpretation of the heavy-ion data.
The polarization of Λ and Λ¯ hyperons along the beam direction has been measured relative to the second and third harmonic event planes in isobar Ru+Ru and Zr+Zr collisions at √sNN = 200 GeV. This is the first experimental evidence of the hyperon polarization by the triangular flow originating from the initial density fluctuations. The amplitudes of the sine modulation for the second and third harmonic results are comparable in magnitude, increase from central to peripheral collisions, and show a mild pT dependence. The azimuthal angle dependence of the polarization follows the vorticity pattern expected due to elliptic and triangular anisotropic flow, and qualitatively disagree with most hydrodynamic model calculations based on thermal vorticity and shear induced contributions. The model results based on one of existing implementations of the shear contribution lead to a correct azimuthal angle dependence, but predict centrality and pT dependence that still disagree with experimental measurements. Thus, our results provide stringent constraints on the thermal vorticity and shear-induced contributions to hyperon polarization. Comparison to previous measurements at RHIC and the LHC for the second-order harmonic results shows little dependence on the collision system size and collision energy.
J/ψ suppression has long been considered a sensitive signature of the formation of the Quark-Gluon Plasma (QGP) in relativistic heavy-ion collisions. In this letter, we present the first measurement of inclusive J/ψ production at mid-rapidity through the dimuon decay channel in Au+Au collisions at √sNN = 200 GeV with the STAR experiment. These measurements became possible after the installation of the Muon Telescope Detector was completed in 2014. The J/ψ yields are measured in a wide transverse momentum (pT) range of 0.15 GeV/c to 12 GeV/c from central to peripheral collisions. They extend the kinematic reach of previous measurements at RHIC with improved precision. In the 0-10% most central collisions, the J/ψ yield is suppressed by a factor of approximately 3 for pT > 5 GeV/c relative to that in p + p collisions scaled by the number of binary nucleon-nucleon collisions. The J/ψ nuclear modification factor displays little dependence on pT in all centrality bins. Model calculations can qualitatively describe the data, providing further evidence for the color-screening effect experienced by J/ψ mesons in the QGP.
We report a new measurement of the production cross section for inclusive electrons from open heavy-flavor hadron decays as a function of transverse momentum (pT) at mid-rapidity (|y|< 0.7) in p+p collisions at s√=200 GeV. The result is presented for 2.5 <pT< 10 GeV/c with an improved precision at high pT with respect to the previous measurements, and thus provides a better constraint on perturbative QCD calculations. Moreover, this measurement also provides a high-precision reference for measurements of nuclear modification factors for inclusive electrons from open-charm and -bottom hadron decays in heavy-ion collisions.
We report a new measurement of the production cross section for inclusive electrons from open heavy-flavor hadron decays as a function of transverse momentum (pT) at mid-rapidity (|y|< 0.7) in p+p collisions at s√=200 GeV. The result is presented for 2.5 <pT< 10 GeV/c with an improved precision above 6 GeV/c with respect to the previous measurements, providing more constraints on perturbative QCD calculations. Moreover, this measurement also provides a high-precision reference for measurements of nuclear modification factors for inclusive electrons from open-charm and -bottom hadron decays in heavy-ion collisions.
The differential cross section for 𝑍0 production, measured as a function of the boson’s transverse momentum (𝑝T), provides important constraints on the evolution of the transverse momentum dependent parton distribution functions (TMDs). The transverse single spin asymmetry (TSSA) of the 𝑍0 is sensitive to one of the polarized TMDs, the Sivers function, which is predicted to have the opposite sign in 𝑝 + 𝑝 → 𝑊 ∕𝑍 + 𝑋 from that which enters in semi-inclusive deep inelastic scattering. In this Letter, the STAR Collaboration reports the first measurement of the 𝑍0∕𝛾∗ differential cross section as a function of its 𝑝T in 𝑝+𝑝 collisions at a center-of-mass energy of 510 GeV, together with the 𝑍0∕𝛾∗ total cross section. We also report the measurement of 𝑍0∕𝛾∗ TSSA in transversely polarized 𝑝+𝑝 collisions at 510 GeV.
We present a systematic analysis of two-pion interferometry in Au+Au collisions at sqrt[sNN]=200GeV using the STAR detector at Relativistic Heavy Ion Collider. We extract the Hanbury-Brown and Twiss radii and study their multiplicity, transverse momentum, and azimuthal angle dependence. The Gaussianness of the correlation function is studied. Estimates of the geometrical and dynamical structure of the freeze-out source are extracted by fits with blast-wave parametrizations. The expansion of the source and its relation with the initial energy density distribution is studied.
Bipolar disorder (BD) is a genetically complex mental illness characterized by severe oscillations of mood and behavior. Genome-wide association studies (GWAS) have identified several risk loci that together account for a small portion of the heritability. To identify additional risk loci, we performed a two-stage meta-analysis of >9 million genetic variants in 9,784 bipolar disorder patients and 30,471 controls, the largest GWAS of BD to date. In this study, to increase power we used ~2,000 lithium-treated cases with a long-term diagnosis of BD from the Consortium on Lithium Genetics, excess controls, and analytic methods optimized for markers on the Xchromosome. In addition to four known loci, results revealed genome-wide significant associations at two novel loci: an intergenic region on 9p21.3 (rs12553324, p = 5.87×10-9; odds ratio = 1.12) and markers within ERBB2 (rs2517959, p = 4.53×10-9; odds ratio = 1.13). No significant X-chromosome associations were detected and X-linked markers explained very little BD heritability. The results add to a growing list of common autosomal variants involved in BD and illustrate the power of comparing well-characterized cases to an excess of controls in GWAS.
The known range of Oxybleptes meridionalis Smetana (Coleoptera: Staphylinidae) is expanded in Florida, USA, from Indian River and Manatee counties to now include Brevard, Highlands, Orange, Seminole and Volusia. Oxybleptes davisi (Notman) is confi rmed to exist in Florida, with records from Leon, Liberty and Wakulla counties in the Panhandle, and Orange County in central Florida. Lissohypnus texanus Casey is newly reported from Florida. A new species, Lissohypnus fullertoni, is described from Florida. Diochus schaumii Kraatz reverts to this original spelling; its widespread form in Florida is identical to that in the northeastern USA.
Adults, and in some species larvae, of several members of Belonuchus Nordmann (Coleoptera: Staphylinidae: Staphylininae) and a few related genera seem to be to various degrees consistently associated with flower bracts of the genus Heliconia (Zingiberales: Heliconiaceae). They are predators and eat various dipterous and lepidopterous larvae in that habitat. Adults of at least Belonuchus cephalotes (Sharp) and Odontolinus fasciatus Sharp are able to immerse completely in water to capture larvae and/or pupae of mosquitoes (Culicidae). Adults and larvae of Belonuchus satyrus Erichson, and adults of B. cacao Blackwelder and B. rufipennis (F.) were found in water-filled flower bracts of Heliconia bihai (L.) L. in northern, lowland Venezuela. The bracts also contained mosquito larvae and semiaquatic coleopterous (Chrysomelidae: Hispinae), lepidopterous (Crambidae: Pyraustinae) and dipterous (Syrphidae, Stratiomyidae, Psychodidae, Richardiidae) larvae, and Annelida. In feeding trials, B. satyrus adults and larvae did not feed on hispine larvae or annelids, but did feed on all the lepidopterous and dipterous larvae available to them; adults dragged larvae and pupae of the mosquito genus Toxorhynchites Theobald from shallow water and thus seemed to be the top predators of the food pyramid within bracts. Records are compiled of association of Belonuchus and relatives with Heliconia bracts in the neotropics. We correct the names used for Heliconia spp. by earlier entomological authors working in Venezuela. Their ‘Heliconia caribaea Lamarck’ is H. bihai (L.) L. and their ‘H. aurea Rodríguez’ is H. bihai cv. Aurea.
The insect fauna within inflorescences of Heliconia bourgaeana Petersen (Zingiberales: Heliconiaceae) was evaluated in Parque Metlac, Fortín de las Flores, Veracruz, Mexico between May and October 1995. Floral bracts were present in May and some persisted to October, despite much destruction in August by a grackle, Quiscalus mexicanus (JF Gmelin) (Icteridae). Flowers were abundant in the bracts in May-June, after which their number declined as fruits matured. Insects that fed on the flowers were most abundant in May-June; several of them could be pollinators; the immature stages of most of these insects were absent from Heliconia Linnaeus. The floral bracts contained water enriched by decomposition of the flowers, and this provided nutrition for aquatic organisms. Syrphid larvae (Diptera) contributed the largest biomass among the aquatic insects, and their distribution among bracts was more uniform in time than that of other aquatic insects. Larvae of Culicidae and Psychodidae (Diptera) were more variable in density and were more abundant after decomposition of the flowers. The most abundant aquatic predators of culicid larvae were larvae of Toxorhynchites Theobald (Culicidae). The most abundant amphibious predators of dipterous larvae were adults of four species of Platydracus Thomson (Staphylinidae), one of them yet undescribed. To capture its prey, the Platydracus adult would immerse its head and thorax, with open mandibles, to snap at passing dipterous larvae.
Four species of mole crickets (Orthoptera: Gryllotalpidae) are known from the West Indies: Neocurtilla hexadactyla (Perty), Scapteriscus abbreviatus Scudder, S. didactylus (Latreille), and S. imitatus Nickle and Castner. All are adventive (not native). We document their distributions in West Indian islands/countries by use of records from the literature and examination of specimens. Scapteriscus abbreviatus has been suggested to have arrived in, and been transported about the West Indies in ship ballast (immigration). Based on records of arrival in various parts of the West Indies and the species’ inability to fly, this suggestion seems reasonable. Scapteriscus imitatus pparently was released in Puerto Rico as a result of mistaken identification (introduction – arriving with assistance from humans – although inadvertent), and has not expanded its range in the West Indies. Although the principal mode of dispersal for the other two species also has been suggested to be ship ballast, we present an alternative based on flight which would seem at least equally as plausible. We suggest that S. didactylus could have dispersed by flight from South America through the Lesser Antilles; likewise N. hexadactyla probably from the Yucatan Peninsula to Cuba, and from South America northward through the Lesser Antilles, in at least some localities assisted by wind. Our zoogeographical alternative, if correct, means that the natural range expansions of these latter two species began very long ago and without human assistance – they were not introduced recently to the West Indies.
Published claims in 1887-1903 that the mole cricket Neocurtilla hexadactyla (Perty) occurs in Puerto Rico all seem to be derived from a misidentification made by Agustín Stahl, a medical practitioner and collector of natural history objects, published in 1882. That species does not seem now to occur in Puerto Rico and almost certainly never did. However, the opportunity still exists for it to colonize by wind-assisted flight from islands to the southeast just as we believe did the mole cricket Scapteriscus didactylus (Latreille) as an immigrant. Stahl evidently mistook the latter for the former. According to some subsequent authors, he also stated that it (the mole cricket now believed to be S. didactylus) arrived in the port of Mayagüez in a cargo of guano about 1850 from Peru and thus colonized Puerto Rico. We found no verification for that story, and we doubt it. The first detection of the presence of S. didactylus in Puerto Rico may have been by a French expedition in 1797, but this species may have been present much earlier. Two other species of Scapteriscus were later detected in Puerto Rico. One, S. abbreviatus Scudder, was detected in 1917 and likely arrived as a contaminant of ship ballast some time earlier, perhaps at the port of Mayagüez. The other, S. imitatus Nickle and Castner, was detected about 1940 and seems to have been introduced inadvertently, as a result of mistaken identity. In broad terms, S. didactylus, S. abbreviatus, and S. imitatus are adventive species (meaning they arrived from somewhere else and are not native) in Puerto Rico. The vernacular name changa in Puerto Rico is owned by S. didactylus, which is called West Indian mole cricket in the English-speaking Caribbean. Historical accounts suggest that populations of S. didactylus and of two pest Phyllophaga spp. (Coleoptera: Scarabaeidae) surged after 1876/1877 and declined after 1920. This coincidence suggests that the cause may have been the same. The cause of the rise might conceivably have been introduction of the mongoose Herpestes javanicus (E. Geoffroy St. Hilaire) in 1877 (because it may have destroyed vertebrate predators) and the cause of the decline might conceivably have been introduction of the toad Bufo marinus L. in 1920, because it is a predator of Phyllophaga and Scapteriscus.
In 1947, 20 species of Staphylinidae were reported from the Cayman Islands as a result of an Oxford University expedition there in 1938 which made extensive use of a light trap. The list is here expanded to 62 species based on collections by R. R. Askew, G. E. Ball, E. A. Dilbert, B. K. Dozier, E. J. Gerberg, P. J. Fitzgerald, M. C. Thomas, and R. H. Turnbow since 1970, all of whom also used light traps except for a collection or two by flight intercept trap.
We document the presence of Larra bicolor Fabricius (Hymenoptera: Crabronidae) in 46 of Florida's 67 counties. The species is represented by two stocks. The first (released in 1981) originated in Pará, Brazil, but was obtained from Puerto Rico, and became established in Broward County in southern Florida. The second (released in 1988) originated in Santa Cruz de la Sierra, Bolivia, and became established in Alachua County in northern Florida. The Bolivian stock, aided by additional satellite releases from Alachua County, is now widely distributed. The species probably occupies all counties in central and northern Florida, but may yet be absent from some southern counties. Introduction was made for classical biological control of invasive mole crickets.
Generic, subgeneric, specific, subspecific, and inlra-subspecific names in Paederus (sensu lato) are compiled alphabetically with literature references, showing that 622 specific names stand in the literature as valid. Five replacement names are required due to homonymy: Paederus cumanus Frank [nom. nou. for Paederus bicolor Wendeler nec Olivier], Paederus sulawesi Frank [nom. nov. for Paederus melanocephlus Heller nec Fabricius], Paederus zairensis Frank [nom. nov. for Paederus orophilus Fagel nec Paederidus brunnescens orophilus (Fagel)], Paederus irianensis Frank [nom. nou. for Paederus litoreus Last nec Paederus littoreus Austin], and Oreopaederus manyemensis Frank [nom. nm. for Oreopaederus ater (Bernhauer) nec Paederidus rubrothoracicus ater (Eichler)]. Four unjustified replacement names (Paederus archeus Blackwelder, Paederus homonymus Blackwelder, Paederus erichsoni Wollaston, and Paederus samoensis Fauvel) are here attributed to their respective senior synonyms (Paederus elongatus Wendeler, Paederus tricolor Erichson, Paederus angolensis Erichson, and Paederus vitiensis Fauvel).
The adventive mole cricket species (Orthoptera: Gryllotalpidae) in Hawaii is apparently Gryllotalpa krishnani Arun Prasanna et al., 2012. The adventive was long thought to be Gryllotalpa africana Palisot de Beauvois, 1805. From 1983 until 2008 it seemed that Gryllotalpa orientalis Burmeister, 1839 might be the adventive’s correct name. However, male genitalia and tegmental characters of Hawaiian specimens match features of G. krishnani and not G. orientalis.
We honor the life and accomplishments of Michael C. Thomas with a short narrative of his professional life along with appendices listing his scientific artwork, bibliography and patronyms. This paper is the first of a Festschrift with contributed remembrances and separate papers honoring him with additional patronyms.