Search results for "CONI"

DNA-Based Identification of Larvae Offers Insights into the Elusive Lifestyles of Native Olive Seed Wasps in South Africa

2020

Wild and cultivated olives in the Western Cape of South Africa are direct or indirect hosts to a high diversity of Braconidae and Chalcidoidea wasps. Olive-associated Braconidae are known to parasitise the larvae of Bactrocera oleae (Rossi), and probably also Bactrocera biguttula (Bezzi). The lifestyle of olive-associated Chalcidoidea is not fully understood, and may include phytophagous, parasitoid and hyperparasitoid species. Some chalcids could represent olive seed wasps (OSW), a generic term that designates the seed feeders responsible for losses in commercial olive production. In order to obtain direct DNA-based evidence for the lifestyle of four putative OSW – Eupelmus spermophilus Si…

Spatial Variation of Leaf Optical Properties in a Boreal Forest Is Influenced by Species and Light Environment

2017

Leaf Optical Properties (LOPs) convey information relating to temporally dynamic photosynthetic activity and biochemistry. LOPs are also sensitive to variability in anatomically related traits such as Specific Leaf Area (SLA), via the interplay of intra-leaf light scattering and absorption processes. Therefore, variability in such traits, which may demonstrate little plasticity over time, potentially disrupts remote sensing estimates of photosynthesis or biochemistry across space. To help to disentangle the various factors that contribute to the variability of LOPs, we defined baseline variation as variation in LOPs that occurs across space, but not time. Next we hypothesized that there wer…

2019

Abstract Salvage logging after disturbances in forests substantially modifies vegetation structure and dead wood availability, but empirical evidence on its impact on biodiversity, especially in European boreal forest, is sparse. In this study we investigated the short-term effect of post-fire salvage logging on species richness and abundance of birds in recently burned mixed coniferous forest. Using point counts we estimated local species composition at 49 salvaged sites and 55 non-intervention sites (burnt forest left for natural regeneration) that were not logged after a fire in south-central Sweden. Local species richness, abundance and Simpson's species diversity index were significant…

Colonization of flax roots and early physiological responses of flax cells inoculated with pathogenic and nonpathogenic strains of Fusarium oxysporum

2003

ABSTRACT Fusarium oxysporum includes nonpathogenic strains and pathogenic strains that can induce necrosis or tracheomycosis in plants. The objective of this study was to compare the abilities of a pathogenic strain (Foln3) and a nonpathogenic strain (Fo47) to colonize flax roots and to induce early physiological responses in flax cell culture suspensions. Both strains colonized the outer cortex of the root; however, plant defense reactions, i.e., the presence of wall appositions, osmiophilic material, and collapsed cells, were less frequent and less intense in a root colonized by Foln3 than by Fo47. Early physiological responses were measured in flax cell suspensions confronted with germin…

Inhibition of Metarhizium anisopliae in the alimentary tract of the eastern subterranean termite Reticulitermes flavipes

2009

Reticulitermes flavipes workers were individually inoculated with 10,000 conidia of the entomopathogenic fungus Metarhizium anisopliae. After being kept in groups of 20 individuals for 1–6 d, histopathological approach showed that most of the inoculated conidia were groomed from the surface of the cuticle by nestmates within 24 h, and that a large number of conidia was subsequently found in different parts of the gut of the groomers. Our observations showed that, among thousands of conidia found in the termite's gut, conidial germination never occurred in all inspected specimens, even when the conidia had the chance to bind to the surface of the cuticular lining of the gut. In addition, whe…

INHIBITION OF THE FUNGAL PATHOGEN METARHIZIUM ANISOPLIAE IN THE ALIMENTARY TRACTS OF FIVE TERMITE (ISOPTERA) SPECIES

2010

We previously showed that in the subterranean termite Reticulitermes flavipes conidia of Metarhizium anisopliae did not germinate in the alimentary tract of living termites and the antifungal activity remained for 2 d post mortem in the gut. We have confirmed that this mechanism is common throughout the termite phylogeny by extending our observations to 5 additional species, from 5 different families. Grooming and ingestion of microorganisms from the cuticle ofnestmate was found to be consistent in all the species and none of the conidia found in the alimentary tracts germinated.

Cellular encapsulation in the eastern subterranean termite, Reticulitermes flavipes (Isoptera), against infection by the entomopathogenic fungus Meta…

2009

Reticulitermes flavipes workers were topically inoculated with approximately 10,000 conidia of the entomopathogenic fungus Metarhizium anisopliae. After being kept in groups of 20 individuals for 1-9 d, histopathological examination showed that termites had an individual immune reaction. The nodule formation at the point of entrance of the fungal hyphae was identified as a cellular encapsulation and the different steps in the nodule formation are described. The relative number of hemocytes per termite increased 24h after fungal exposure and remained high in the hemolymph for at least 3 d before decreasing back to pre-exposure levels. The role of an individual immune cellular reaction in soc…

Nitric oxide: comparative synthesis and signaling in animal and plant cells.

2001

Since its identification as an endothelium-derived relaxing factor in the 1980s, nitric oxide has become the source of intensive and exciting research in animals. Nitric oxide is now considered to be a widespread signaling molecule involved in the regulation of an impressive spectrum of mammalian cellular functions. Its diverse effects have been attributed to an ability to chemically react with dioxygen and its redox forms and with specific iron- and thiol-containing proteins. Moreover, the effects of nitric oxide are dependent on the dynamic regulation of its biosynthetic enzyme nitric oxide synthase. Recently, the role of nitric oxide in plants has received much attention. Plants not only…

Arctic avian predators synchronise their spring migration with the northern progression of snowmelt

2020

AbstractMigratory species display a range of migration patterns between irruptive (facultative) to regular (obligate), as a response to different predictability of resources. In the Arctic, snow directly influences resource availability. The causes and consequences of different migration patterns of migratory species as a response to the snow conditions remains however unexplored. Birds migrating to the Arctic are expected to follow the spring snowmelt to optimise their arrival time and select for snow-free areas to maximise prey encounter en-route. Based on large-scale movement data, we compared the migration patterns of three top predator species of the tundra in relation to the spatio-te…

New Mitochondrial Gene Rearrangement in Psyttalia concolor, P. humilis and P. lounsburyi (Hymenoptera: Braconidae), Three Parasitoid Species of Econo…

2020

The family Braconidae consists mostly of specialized parasitoids, some of which hold potential in biocontrol of agricultural pests. Psyttalia concolor, Psyttalia humilis and Psyttalia lounsburyi are parasitoids associated with Bactrocera oleae, a major pest of cultivated olives. The native range of Psyttalia concolor is the Mediterranean, and P. humilis and P. lounsburyi are native to sub-Saharan Africa. This study reports the mitochondrial genomes of the three species, thus laying the foundation for mitogenomic analyses in the genus Psyttalia. Comparative mitogenomics within Braconidae showed a novel gene arrangement in Psyttalia in involving translocation and inversion of transfer RNA gen…