Search results for "classification"

2021

Hosts of brood parasitic cuckoos often employ mobbing attacks to defend their nests and, when mobbing is costly, hosts are predicted to adjust their mobbing to match parasitism risk. While evidence exists for fine-tuned plasticity, it remains unclear why mobbing does not track larger seasonal changes in parasitism risk. Here we test a possible explanation from parental investment theory: parents should defend their current brood more intensively as the opportunity to replace it declines (re-nesting potential), and therefore “counteract” any apparent seasonal decline to match parasitism risk. We take advantage of mobbing experiments conducted at two sites where reed warblers (Acrocephalus sc…

Assessing escapes from short rotation plantations of the invasive tree species Robinia pseudoacacia L. in Mediterranean ecosystems: a study in centra…

2016

Abstract: Black locust (Robinia pseudoacacia L.) is a fast growing tree species native to temperate North America, and widely diffused and naturalized in Europe. It is one of the candidate species for establishing bioenergy plantations on marginal lands in temperate and sub-Mediterranean regions. This potential is in contrast to its well-known invasive habit, leading to a potential damage to plant biodiversity in many European countries. Advise against black locust plantation in regions where it is already invasive has been issued by several international reports, as well as the adoption of mitigation measures (e.g., “containment” buffer zones) to prevent the spread of the species into natu…

Bush pig (Potamochoerus porcus) seed predation of bush mango (Irvingia gabonensis) and other plant species in Democratic Republic of Congo.

2012

4 pages; International audience

Periphyton support for littoral secondary production in a highly humic boreal lake

2016

Steep stratification and poor light penetration in highly humic lakes typically restrict oxygenated littoral areas to narrow lake margins. However, in some instances, surrounding floating vegetation mats can sustain highly productive periphyton and more diverse invertebrate communities than pelagic areas. Little is known about how these littoral food webs function or the extent to which the pelagic and littoral food webs are coupled. We added 15N-labeled ammonium nitrate to the floating moss mat surrounding the littoral zone of Mekkojärvi, a small highly humic and fishless lake in southern Finland. Our goal was to increase the δ15N values of periphyton to investigate the diets of littoral i…

Biology and Behaviour of Cirrospilus diallus and Cirrospilus pictus, Parasitoids of Phyllocnistis citrella

2005

International audience; Studies were carried out on some biological and behavioral aspects of Cirrospilus diallus Walker and Cirrospilus pictus (Nees) (Hymenoptera: Eulophidae) in relation to their host, the citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae). Adults of both species fed with sugar lived on average 4.45 +/- 0.19 days, whereas adults provided with honey survived on average 40.62 +/- 1.97 days. Rates of host mortality due to parasitoid stings without oviposition were as high as 31.25 and 37.73% for C. pictus and C. diallus, respectively. Both species showed arrhenotokous parthenogenesis. Sex ratios of parasitoids emerging from the 2nd and 3rd …

Characterization and evolution of two bacteriome-inhabiting symbionts in cixiid planthoppers (Hemiptera: Fulgoromorpha: Pentastirini).

2009

International audience; Like other plant sap-sucking insects, planthoppers within the family Cixiidae (Insecta: Hemiptera: Fulgoromorpha) host a diversified microbiota. We report the identification and first molecular characterization of symbiotic bacteria in cixiid planthoppers (tribe: Pentastirini). Using universal eubacterial primers we first screened the eubacterial 16S rRNA sequences in Pentastiridius leporinus (Linnaeus) with PCR amplification, cloning, and restriction fragment analysis. We identified three main 16S rRNA sequences that corresponded to a Wolbachia bacterium, a plant pathogenic bacterium, and a novel gammaproteobacterial symbiont. A fourth bacterial species affiliated w…

Potential of Crotalaria species as green manure crops for the management of pathogenic nematodes and beneficial mycorrhizal fungi

2004

On the basis of preliminary experiments, some Crotalaria species from Senegal were investigated to determine (1) their susceptibility to Meloidogyne javanica and M. incognita compared to a sensitive host (tomato), (2) their mycorrhizal and rhizobial responses, and (3) the effect of their cultivation on the mycorrhizal soil infectivity. The nematode invasion rates on Crotalaria spp. ranked from 0.17 to 7.17% and from 0.58 to 5.25%, respectively, for M. incognita and M. javanica, vs. 97% and 77% on tomato. Moreover, the inoculated J2 which invaded tomatoes developed into adult females, while those on Crotalaria spp. rarely developed beyond the third stage, confirming that all Crotalaria spp. …

The potential of nonpathogenic Fusarium oxysporum and other biological control organisms for suppressing fusarium wilt of banana

2006

Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; The aim of this study was to evaluate the ability of nonpathogenic F. oxysporum and Trichoderma isolates from suppressive soils in South Africa to suppress fusarium wilt of banana in the glasshouse. Several biological control agents and commercial biological control products were included in the study. The isolates were first screened in vitro on potato dextrose agar. In glasshouse evaluations, the fungal and bacterial isolates were established on banana roots before they were repla…

Activation of MAPK homologues by elicitors in tobacco cells

1998

Elicitors of plant defence reactions (such as cryptogein, an elicitin produced by Phytophthora cryptogea, or oligogalacturonides (OGs)), induced in tobacco cell suspensions (Nicotiana tabacum var Xanthi) a rapid and transient activation of two protein kinases (PKs) with apparent molecular masses of 50 and 46 kDa, respectively. These PKs activated and phosphorylated at tyrosine residues, phosphorylated myelin basic protein (MBP) at serine/threonine residues. Both are recognized by anti-MAPK antibodies. The two MBP kinases possessed the same kinetics of activation, and their activation depended, to the same extent, on different exogenously applied compounds (staurosporine, lanthanum, EGTA). W…

Comparative analysis of the proximate and elemental composition of the blue crab Callinectes sapidus, the warty crab Eriphia verrucosa, and the edibl…

2016

AbstractThe proximate composition and element contents of claw muscle tissue of Atlantic blue crabs (Callinectes sapidus) were compared with the native warty crab (Eriphia verrucosa) and the commercially edible crab (Cancer pagurus). The scope of the analysis was to profile the chemical characteristics and nutritive value of the three crab species. Elemental fingerprints showed significant inter-specific differences, whereas non-significant variations in the moisture and ash contents were observed. In the blue crab, protein content was significantly lower than in the other two species, while its carbon content resulted lower than that characterizing only the warty crab. Among micro-elements…