30 research outputs found

    First Record of the Inquiline Ant Leptothorax kutteri Buschinger, 1965 from Turkey

    Get PDF
    We report on the occurrence of the ant Leptothorax kutteri Buschinger, 1965 in two sites in Northern and Eastern Turkey. Leptothorax kutteri is a workerless inquiline living in the colonies of L. acervorum (Fabricius, 1793) so far known from various parts of Northern and Central Europe. Our findings greatly increase the range of this small and rare ant

    The Evolution of Invasiveness in Garden Ants

    Get PDF
    It is unclear why some species become successful invaders whilst others fail, and whether invasive success depends on pre-adaptations already present in the native range or on characters evolving de-novo after introduction. Ants are among the worst invasive pests, with Lasius neglectus and its rapid spread through Europe and Asia as the most recent example of a pest ant that may become a global problem. Here, we present the first integrated study on behavior, morphology, population genetics, chemical recognition and parasite load of L. neglectus and its non-invasive sister species L. turcicus. We find that L. neglectus expresses the same supercolonial syndrome as other invasive ants, a social system that is characterized by mating without dispersal and large networks of cooperating nests rather than smaller mutually hostile colonies. We conclude that the invasive success of L. neglectus relies on a combination of parasite-release following introduction and pre-adaptations in mating system, body-size, queen number and recognition efficiency that evolved long before introduction. Our results challenge the notion that supercolonial organization is an inevitable consequence of low genetic variation for chemical recognition cues in small invasive founder populations. We infer that low variation and limited volatility in cuticular hydrocarbon profiles already existed in the native range in combination with low dispersal and a highly viscous population structure. Human transport to relatively disturbed urban areas thus became the decisive factor to induce parasite release, a well established general promoter of invasiveness in non-social animals and plants, but understudied in invasive social insects

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

    Get PDF
    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    First Record of the Inquiline Ant Leptothorax kutteri Buschinger, 1965 from Turkey

    No full text
    We report on the occurrence of the ant Leptothorax kutteri Buschinger, 1965 in two sites in Northern and Eastern Turkey. Leptothorax kutteri is a workerless inquiline living in the colonies of L. acervorum (Fabricius, 1793) so far known from various parts of Northern and Central Europe. Our findings greatly increase the range of this small and rare ant

    Unusual Ant Hosts of the Socially Parasitic Ant Anergates atratulus (Schenck, 1852) (Hymenoptera, Formicidae)

    No full text
    The extreme inquiline ant Anergates atratulus (Schenck, 1852) (Hymenoptera, Formicidae) was collected in ant nests of Tetramorium moravicum Kratochvil, 1941 in Bulgaria and of T. chefketi Forel, 1911 in Bulgaria and Turkey. The reported ant hosts belong to the Tetramorium chefketi species complex in contrast with the typical hosts from Tetramorium caespitum/impurum complex. This finding confirms the assumption that a broader range of host species for the socially parasitic species A. atratulus may be expected. Present data on the new host species expand knowledge about biology of this rare ant species, included in the IUCN Red List of threatened species

    A striking color variation is detected in Ponera testacea Emery, 1895 (Hymenoptera, Formicidae) across its Western Palaearctic geographic range

    No full text
    In this paper, we provide numeric morphology-based evidence that the dark-colored Ponera coarctata var. lucida Emery, 1898, formerly considered a synonym of P. coarctata (Latreille, 1802), is conspecific with the lighter-colored Ponera testacea Emery, 1895. Species hypotheses are developed via NC-PART clustering, combined with Partitioning Algorithm based on Recursive Thresholding (PART), and via PCA combined with gap statistics. We obtained our results from an extensive dataset from the 10 continuous morphometric traits measured on 165 workers belonging to 73 nest samples. Linear discriminant analysis (LDA) confirmed the grouping of hypotheses generated by exploratory analyses with 100% classification success when all ten morphometric traits were involved. The Anatolian Turkish black and the predominantly European yellow samples, did not separate based on their morphometric characteristics. These two color variations broadly overlap in their geographic range in Anatolian Turkey. The investigated type series of Ponera coarctata var. lucida Emery, 1898 (collected from Kazakhstan) fell within the P. testacea cluster instead of P. coarctata and is also classified with high certainty as P. testacea by confirmatory LDA. Therefore, we propose the synonymy of Ponera coarctata var. lucida Emery, 1898 with Ponera testacea Emery, 1895. As no other morphological differences than color patterns were detected between the “black” and “pale” P. testacea samples, we hold that these populations constitute geographically occurring color variations of the same species. Finally, our quantitative morphology-based results show that relying on color patterns is not a robust approach in identifying European Ponera samples, particularly in the east, but using multivariate analyses of morphometric traits is advised instead

    Three new species of ants (genus Aphaenogaster, Hymenoptera : Formicidae) from Turkey

    No full text
    WOS: 000259141400016Three new species of the ant genus Aphaenogaster (A. aktaci sp. n., A. maculifrons sp. n., A. radchenkoi sp. n.) are described from Turkey and their taxonomic positions are discussed. Aphaenogaster aktaci sp. n. belongs to the obsidiana group, A. maculifrons sp. n. to subterranea group and A. radchenkoi sp. n. to pallida group of the Attomyrma subgenus. Key characteristics for identification of the species and data on their ecology are given
    corecore