Six new non-native ants (Formicidae) in the Canary Islands and their possible impacts

Biological invasions are one of the main causes of biodiversity loss, especially on oceanic islands. Ants are among the most damaging pests in the world. After systematic sampling of more than 1,000 localities in the Canary Islands, six new exotic ant species are reported for the first time: Pheidole bilimeki (Myrmicinae), Pheidole navigans (Myrmicinae), Strumigenys membranifera (Myrmicinae), Brachymyrmex cordemoyi (Formicinae), Tapinoma darioi (Dolichoderinae) and Technomyrmex pallipes (Dolichoderinae). Moreover, another two recently reported species have been genetically confirmed. Morphological and genetic data were analysed to confirm the identity of the new records. For each species, information regarding identification, distribution, global invasive records and possible impacts is given. The arrival of these species may endanger local biodiversity.

Hernández-Teixidor, David; Pérez-Delgado, Antonio José; Suárez, Daniel; Reyes-López, Joaquin

Journal of Applied Entomology 1-8 (2020)
DOIDigital.CSIC

Effect of diurnal vs. nocturnal pollinators and flower position on the reproductive success of Echium simplex

Nocturnal pollination plays an important role in sexual plant reproduction but has been overlooked, partially because of intrinsic difficulties in field experimentation. Even less attention has received the effect of within-inflorescence spatial position (distal or proximal) on nocturnal pollinators of columnar plants, despite numerous studies examining the relationship between such position and reproductive success. Woody endemic Echium simplex possesses large erect inflorescences bearing thousands of flowers which are visited by a wide array of diurnal and nocturnal animals. In this study, we identified nocturnal visitors and compared their pollination effectiveness with that of diurnal pollinators in different inflorescence sections by means of selective exclosures in NE Tenerife (Canary Islands). Nocturnal visitors included at least ten morphospecies of moths (such as Paradrina rebeli and Eupithecia sp.), two coleopteran species (mainly Alloxantha sp.), neuropterans (Chrysoperla carnea), dictyopterans (Phyllodromica brullei), dermapterans (Guanchia sp.) and julidans (Ommatoiulus moreletii). In general, plants excluded from pollinators set less fruits than open-pollination (control) plants which set fruits homogeneously across sections. Diurnally pollinated plants set more fruit in their upper parts whereas nocturnally pollinated plants set fruit in both upper and bottom sections. We conclude that although the frequency and diversity of diurnal pollinators is far higher than that of nocturnal pollinators, both exhibit different foraging behaviour that generates complementary effects on the reproductive success of E. simplex.

Jaca, Julia; Nogales, Manuel; Traveset, Anna

Arthropod Plant Interactions 14: 409–419 (2020)
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Two new dipluran species unearthed from subterranean habitats of the Canary Islands (Arthropoda, Hexapoda, Entognatha)

Two new dipluran species of the family Campodeidae have been unearthed in the Canary Islands. Remycampa herbanica sp. nov. was found in a highly threatened lava tube on Fuerteventura island. It is related to the soil-dwelling northwest African Remycampa launeyi that also inhabits four of the Canary Islands. The two known Remycampa species are characterized by a torsion of the labial palps. They differ chiefly in the distribution of macrosetae and in the features of cave adaptation of R. herbanica, i.e. elongation of body and appendages, and a higher number of olfactory chemoreceptors with a coniform shape unique within campodeids. Spaniocampa relicta sp. nov. was collected in the mesovoid shallow substratum (MSS) and has been assigned to a formerly monotypic genus that includes the soil-dwelling Spaniocampa prima from the Republic of Guinea. The two species differ in the number of abdominal macrosetae. Females of S. relicta sp. nov. have small setae arranged in groups along the posterior border of the first urosternite. These structures of unknown function have never been described in other campodeid species. Sequencing the COI barcode region of R. herbanica has been produced but it proved insufficient to identify closest relatives. The two new hexapods from subterranean habitats raise the Canarian campodeid fauna to six species. Five of them are living in soil and/or MSS, whereas the cave-adapted R. herbanica is known only from a single, particularly endangered lava tube distant from other caves.

Sendra, Alberto; López, Heriberto; Selfa, Jesús; Oromí, Pedro

Subterranean Biology 34: 39–59 (2020)
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Chemical Composition of an Aphid Antifeedant Extract from an Endophytic Fungus, Trichoderma sp. EFI671

Botanical and fungal biopesticides, including endophytes, are in high demand given the current restrictive legislations on the use of chemical pesticides. As part of an ongoing search for new biopesticides, a series of fungal endophytes have been isolated from selected medicinal plants including Lauraceae species. In the current study, an extract from the endophytic fungus Trichoderma sp. EFI 671, isolated from the stem parts of the medicinal plant Laurus sp., was screened for bioactivity against plant pathogens (Fusarium graminearum, Rhizoctonia solani, Sclerotinia sclerotiorum and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi) and plant parasites (Meloidogyne javanica), with positive results against M. persicae. The chemical study of the neutral fraction of the active hexane extract resulted in the isolation of a triglyceride mixture (m1), eburicol (2), β-sitostenone (3), ergosterol (4) and ergosterol peroxide (5). The free fatty acids present in the acid fraction of the extract and in m1 (oleic, linoleic, palmitic and stearic) showed strong dose-dependent antifeedant effects against M. persicae. Liquid (potato dextrose broth, PDB and Sabouraud Broth, SDB) and solid (corn, sorghum, pearl millet and rice) growth media were tested in order to optimize the yield and bioactivity of the fungal extracts. Pearl millet and corn gave the highest extract yields. All the extracts from these solid media had strong effects against M. persicae, with sorghum being the most active. Corn media increased the methyl linoleate content of the extract, pearl millet media increased the oleic acid and sorghum media increased the oleic and linoleic acids compared to rice. The antifeedant effects of these extracts correlated with their content in methyl linoleate and linoleic acid. The phytotoxic effects of these extracts against ryegrass, Lolium perenne, and lettuce, Lactuca sativa, varied with culture media, with sorghum being non- toxic.

Kaushik, Nutan; Díaz, Carmen E.; Chhipa, Hemraj; Fernando Julio, L.; Fe Andrés, M.; González-Coloma, Azucena

Microorganism 8(3): 420 (2020)
DOIDigital.CSIC

Synthetic Approaches to Phosphasugars (2-oxo-1,2-oxaphosphacyclanes) Using the Anomeric Alkoxyl Radical β-Fragmentation Reaction as the Key Step

The anomeric alkoxyl radical β-fragmentation (ARF) of carbohydrates possessing an electron-withdrawing group (EWG) at C2, promoted by PhI(OAc)2/I2, gives rise to an acyclic iodide through which a pentavalent atom of phosphorus can be introduced via the Arbuzov reaction. After selective hydrolysis and subsequent cyclization, the phosphonate or phosphinate intermediates can be converted into 2-deoxy-1-phosphahexopyranose and 2-deoxy-1-phosphapentopyranose sugars. The ARF of carbohydrates with an electron-donor group (EDG) at C2 proceeds by a radical-polar crossover mechanism, and the cyclization occurs by nucleophilic attack of a conveniently positioned phosphonate or phosphinate group to the transient oxocarbenium ion. This alternative methodology leads to 5-phosphasugars with a 4-deoxy-5-phosphapentopyranose framework. The structure and conformation of the 2-oxo-1,2-oxaphosphinane and 2-oxo-1,2-oxaphospholane ring systems in different carbohydrate models have been studied by NMR and X-ray crystallography.

Hernández-Guerra, Daniel; Kennedy, Alan R.; León, Elisa I.; Martín, Ángeles; Pérez-Martín, Inés; Rodríguez Morales, María S.; Suárez, Ernesto

Journal of Organic Chemistry 85 (7): 4861-4880 (2020)
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Short and modular synthesis of tetraarylsalicylaldehydes

In this study, we describe a novel strategy that allows the obtention of all 15 possible substitution geometries of perarylated salicylaldehydes with total control of the regioselectivity. This strategy entitles the formation of the salicylaldehyde core via a Claisen rearrangement of propargyl vinyl ethers, followed by bromination and Pd-catalyzed aryl–aryl cross-coupling reactions.

Tejedor, David; Delgado-Hernández, Samuel; Santamaría-Peláeza, Blanca; García-Tellado, Fernando 

Chemical Communications 56: 4019-4022 (2020)
DOIDigital.CSIC

BPEC: An R Package for Bayesian Phylogeographic and Ecological Clustering

BPEC is an R package for Bayesian phylogeographic and ecological clustering which allows geographical, environmental and phenotypic measurements to be combined with deoxyribonucleic acid (DNA) sequences in order to reveal geographic structuring of DNA sequence clusters consistent with migration events. DNA sequences are modelled using a collapsed version of a simplified coalescent model projected onto haplotype trees, which subsequently give rise to constrained clusterings as migrations occur. Within each cluster, a multivariate Gaussian distribution of the covariates (geographical, environmental, phenotypic) is used. Inference follows tailored reversible jump Markov chain Monte Carlo sampling so that the number of clusters (i.e., migrations) does not need to be pre-specified. A number of output plots and visualizations are provided which reflect the posterior distribution of the parameters of interest. BPEC also includes functions that create output files which can be loaded into Google Earth. The package commands are illustrated through an example dataset of the polytypic Near Eastern brown frog Rana macrocnemis analyzed using BPEC.

Manolopoulou, Ioanna; Hille, Alex; Emerson, Brent C.

Journal of Statistical Software 92(5): 1-32 (2020)
DOIDigital.CSIC

Composition and biocidal properties of essential oil from pre-domesticated Spanish Satureja Montana

The aim of this study was to develop a chemically stable plant following a pre-domestication process and the valorization of its essential oil for the production of biopesticides. This study was conducted during four growing seasons to give a pre-domesticated population (SAMO-0). The resulting pre-domesticated population increased the hydrodistilled oil yield (average 0.45%) and maintained a stable yield of dry material (44.5%). The plant material was submitted to pilot plant scale steam distillation under three pressures (0.5, 1.0 and 1.5 bar) with lower yield (average 0.15%). The essential oil showed a carvacrol / p-cymene chemotype. The pre-domestication process increased β-myrcene, α- and γ-terpinene, p-cymene, thymol and β-bisabolene; and decreased α-thujene and carvacrol. The steam distillation increased the oil content in α-thujene, α-pinene, α-terpinene, p-cymene and trans-caryophyllene, and decreased borneol, thymoquinone thymol and β-bisabolene. Pressure increased α-terpinene, thymol and carvacrol Additionally, the study of the biocidal effects (against the insect pests Spodoptera littoralis, Myzus persicae and Leptinotarsa decemlineata and the phytopathogenic nematode Meloydogine javanica) of the EOs showed that overall, the most active oils were the hydrodistilled (to all insect species), followed by the steam distilled oils with higher carvacrol and thymol content (pressures of 1.5 and 1.0 bar). Carvacrol and thymol were responsible for the activity of these oils on M. persicae, and L. decemlineata but only partially on S. littoralis. The steam distilled oils showed strong nematicidal activity against M. javanica that could be partially explained by their content in active carvacrol and thymol.

Navarro-Rocha, Juliana; Andrés, María Fe; Díaz, Carmen E.; Burillo, Jesús; González-Coloma, Azucena

Industrial Crops and Products 145: 111958 (2020)
DOIDigital.CSIC

Mitochondrial Metagenomics Reveals the Ancient Origin and Phylodiversity of Soil Mites and Provides a Phylogeny of the Acari

High-throughput DNA methods hold great promise for phylogenetic analysis of lineages that are difficult to study with conventional molecular and morphological approaches. The mites (Acari), and in particular the highly diverse soil-dwelling lineages, are among the least known branches of the metazoan Tree-of-Life. We extracted numerous minute mites from soils in an area of mixed forest and grassland in southern Iberia. Selected specimens representing the full morphological diversity were shotgun sequenced in bulk, followed by genome assembly of short reads from the mixture, which produced >100 mitochondrial genomes representing diverse acarine lineages. Phylogenetic analyses in combination with taxonomically limited mitogenomes available publicly resulted in plausible trees defining basal relationships of the Acari. Several critical nodes were supported by ancestral-state reconstructions of mitochondrial gene rearrangements. Molecular calibration placed the minimum age for the common ancestor of the superorder Acariformes, which includes most soil-dwelling mites, to the Cambrian–Ordovician (likely within 455–552 Ma), whereas the origin of the superorder Parasitiformes was placed later in the Carboniferous-Permian. Most family-level taxa within the Acariformes were dated to the Jurassic and Triassic. The ancient origin of Acariformes and the early diversification of major extant lineages linked to the soil are consistent with a pioneering role for mites in building the earliest terrestrial ecosystems.

Arribas, Paula; Andújar, Carmelo ; Lourdes Moraza, María; Linard, Benjamin; Emerson, Brent C.; Vogler, Alfried P.

Molecular Biology and Evolution 37(3): 683–694 (2020)
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Potential role of lava lizards as pollinators across the Galápagos Islands

Lizards have been reported as important pollinators on several oceanic islands. Here we evaluate the potential role of Galápagos lava lizards (Microlophus spp.) as pollinators across their radiation. Over 3 years, we sampled pollen transport by 9 lava lizard species on the 10 islands where they are present, including 7 single‐island endemics. Overall, only 25 of 296 individuals sampled (8.4%) transported pollen of 10 plant species, the most common being Prosopis juliflora, Exodeconus miersii, Sesuvium sp. and Cordia leucophlyctis. At least 8 of these plant species were native, and none were confirmed as introduced to the archipelago. Despite the low overall proportion of individuals carrying pollen, this was observed in 7 of the nine lizard species, and on 8 of the ten main islands (Española, Fernandina, Floreana, Isabela, Marchena, Pinta, Santa Cruz and Santiago), suggesting that this is a widespread interaction. The results reported here support the potential role of lava lizards as pollinators across their radiation, although they may represent a relatively modest contribution when compared with birds and insects. However, we cannot discard that lizards may be ecologically significant for particular plant species and ecosystems given the specific climatic condition and functional diversity of each island.

Hervías-Parejo, Sandra; Nogales, Manuel; Guzmán, Beatriz; Trigo, María del Mar; Olesen, Jens M.; Vargas Pablo; Heleno, Rubén H.; Traveset, Anna

Integrative Zoology 15(2): 144-148 (2020)
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