Palatability of glyphosate in ants: a field experiment reveals broad acceptance of highly polluted solutions in a Mediterranean ant

Glyphosate is a systemic herbicide still used in many countries, though there are several known detrimental effects on animals. Previous studies concerning its effects on social insects are available, but they are primarily focused on honeybees; little is known about the interactions of this compound with ants. Here, we assessed whether different concentrations of glyphosate can be perceived by ant workers and to what extent. As a model species, we used the Mediterranean ant Crematogaster scutellaris, commonly found in agroecosystems. We performed 3000 individual tests of acceptance using ten different solutions of various concentrations of the herbicide. Half of the solutions contained added sucrose in order to test the possible masking effect of the sugar taste on glyphosate. We used comparable glyphosate concentrations to those previously used in other studies on social insects or suggested by the producer. We found that the acceptance of the solutions decreased as the concentration of the herbicide increased. However, a significant percentage of ants drank the solutions with concentrations up to dozens of times higher than those inducing toxic effects in bees. In light of these results, we urge further assessment of the effects of glyphosate on ants, particularly because the food ingested by workers is transferred to the brood and queens, posing a potential threat to the health of the entire colony. Surprisingly, we did not record any difference in acceptance between solutions with and without sugar; this point is discussed regarding drought stress.info:eu-repo/semantics/publishedVersio

Diversity and Conservation Gap Analysis of the Solanaceae of Southern South America

There is a need to make substantial advances in the taxonomic, systematic, and distribution knowledge of plants, and find better ways of transmission of this information to society to surpass the general pattern described as “plant blindness.” The diversity of the plant family Solanaceae reaches its peak in South America; however, many of its species are threatened due to the expansion of the human footprint. Here, we examine the diversity patterns of the family in southern South America (Argentina and Chile) by means of species richness (SR), weighted endemism (WE), and corrected weighted endemism (CWE). We also evaluated conservation gaps in relation to protected areas and the human footprint as a proxy for potential impacts on this biodiversity. Results show two richness centers in NW and NE Argentina, with a high degree of overlap with protected areas, which, on the other side, show a relative high index of human footprint. Comparatively, coastal Atacama (Chile) shows lower richness values, but outstanding CWE and WE values. The coast of Atacama harbors high values due the presence of species of the genus Nolana with restricted distributions. Protected areas in this tight coastal strip are sparse, and the human footprint is also relatively high. The degree of protection based on these parameters is then unbalanced, highlighting the need for a geographically explicit strategy for the conservation of the family at subcontinental scale. In doing so, it is likely that other representatives of these unique centers of richness and endemism will benefit.Fil: Moreira Muñoz, Andrés Sergio. Pontificia Universidad Católica de Valparaíso; ChileFil: Palchetti, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Morales Fierro, Vanesa. Universidad Provincial de Cordoba.; ArgentinaFil: Duval, Valeria Soledad. Universidad Nacional del Sur. Departamento de Geografía y Turismo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Allesch Villalobos, Ruddy. Pontificia Universidad Católica de Valparaíso; ChileFil: González Orozco, Carlos. Corporación Colombiana de Investigación Agropecuaria.; Colombi

What anions do inside a receptor's cavity: A trifurcate anion receptor providing both electrostatic and hydrogen-bonding interactions

The trifurcate receptor 13+ forms stable 1:1 complexes with halide and oxo anions in MeCN solution, as shown by spectrophotometric and 1H NMR experiments, and selectively recognizes chloride (lgKass>7) in the presence of fluoride and bromide. The high stability reflects the receptor7s ability to donate up to six hydrogen bonds (from three pyrrole N_H and three C_H fragments, polarized by the proximate positive charge) to the included anion. Addition of an excess of more basic anions (F_ and CH3COO_) induces stepwise deprotonation of the N_H groups, an event signalled by the appearance of a bright yellow color. Crystal and molecular structures are reported for the complex with NO3_ and a capsule consisting of two interconnected trifurcate subunits, one of which includes an H-bound Br_ ion, while the other is doubly deprotonated and includes an H-bound water molecule. Finally, evidence is given for the formation in solution of an authentic complex of OH_, in which H-bound hydroxide is included within the cavity of 13+

Anion receptors containing -NH binding sites: hydrogen-bond formation or neat proton transfer

When the amide-contg. receptor (I) is in a soln. of DMSO (DMSO) in the presence of basic anions (CH3COO-, F-, H2PO4-), it undergoes deprotonation of the -NH fragment to give the corresponding zwitterion, which can be isolated as a cryst. solid. In the presence of less basic anions (Cl-, Br-, NO3-), I establishes true hydrogen-bond interactions of decreasing intensity. The less acidic receptor II undergoes neat proton transfer with only the more basic anions CH3COO- and F-, and establishes hydrogen-bond interactions with H2PO4-. An empirical criterion for discerning neutralization and hydrogen bonding, based on UV/Vis and 1H NMR spectra, is proposed