Search results for "ENTO"
showing 10 items of 11102 documents
The structure of ant assemblages in an urban area of Helsinki, southern Finland
2008
We collected ants in ten replicated habitat types of an urban island and described their assemblages using Non-metric Multidimensional Scaling and Multivariate Regression Trees. Lasius niger was the most abundant species, followed by Myrmica rubra, Formica fusca, L. flavus and L. platythorax; these species comprised 87% of all 1133 nests of the 16 species found. Ant assemblages changed gradually from open habitats to sites with closed tree canopy. Species most tolerant to urban pressure were L. niger, L. flavus and M. rugulosa, whereas forest-associated species were scarce or absent. Successful urban species had extensive (Palaearctic) or more limited (Euro-Siberian) distribution. Common an…
The response of an egg parasitoid to substrate-borne semiochemicals is affected by previous experience
2016
AbstractAnimals can adjust their behaviour according to previous experience gained during foraging. In parasitoids, experience plays a key role in host location, a hierarchical process in which air-borne and substrate-borne semiochemicals are used to find hosts. In nature, chemical traces deposited by herbivore hosts when walking on the plant are adsorbed by leaf surfaces and perceived as substrate-borne semiochemicals by parasitoids. Chemical traces left on cabbage leaves by adults of the harlequin bug (Murgantia histrionica) induce an innate arrestment response in the egg parasitoid Trissolcus brochymenae characterized by an intense searching behaviour on host-contaminated areas. Here we …
Mating Status of an Herbivorous Stink Bug Female Affects the Emission of Oviposition-Induced Plant Volatiles Exploited by an Egg Parasitoid
2019
Insect parasitoids are under selection pressure to optimize their host location strategy in order to maximize fitness. In parasitoid species that develop on host eggs, one of these strategies consists in the exploitation of oviposition-induced plant volatiles (OIPVs), specific blends of volatile organic compounds released by plants in response to egg deposition by herbivorous insects. Plants can recognize insect oviposition via elicitors that trigger OIPVs, but very few elicitors have been characterized so far. In particular, the source and the nature of the elicitor responsible of egg parasitoid recruitment in the case of plants induced with oviposition by stink bugs are still unknown. In …
How to Deal with Uninvited Guests in Wine: Copper and Copper-containing Oxidases
2020
Copper is one of the most frequently occurring heavy metals in must and wine. It is introduced by pesticides, brass fittings, and as copper sulphate for treatment of reductive off-flavors. At higher concentrations, copper has harmful effects on the wine. It contributes to the oxidation of wine ingredients, browning reactions, cloudiness, inhibition of microorganisms, and wine fermentation. Last but not least, there is also a danger to the consumer. At present, some physicochemical methods exist to reduce the copper content in must and wine, but they all have their shortcomings. A possible solution is the biosorption of metals by yeasts or lactobacilli. Copper can also reach must and wine in…
Spatial distribution ofVespa velutinaindividuals hunting at domestic honeybee hives: heterogeneity at a local scale
2014
Since its recent introduction into Europe, the yellow-legged hornet, Vespa velutina, has become a major predator of the domestic honeybee, Apis mellifera, but little is known about its hunting behavior. We studied V. velutina hunting behavior by a capture-mark-recapture procedure in an experimental apiary. A total of 360 hornets were captured and tagged, and we determined: (i) the number of hornets visiting the apiary and the changes in time, (ii) the average number of individual visits per half-day and the time elapsed between consecutive recaptures, and (iii) the individual and global distribution of the hornets in the apiary. More than 50% of the marked hornets were recaptured at least o…
Behavioral syndrome in a native and an invasive hymenoptera species
2014
Recent studies have focused on the role of behavior in biological invasions. Individuals may differ consistently in time for several behavioral traits (personality) which covary(behavioralsyndrome)resultingindifferentbehavioraltypes,someofthemfavoring invasion. Social hymenopterans have a strong potential to be invaders and their success depends primarily on the foundresses' ability to found viable colonies. They are expected to be active, explorative and bold for optimally establishing their nest. In Europe, 2 hornet species coexist: the native Vespa crabro and the invasive Vespa velutina. These 2 species may compete for nesting sites and we suggest that the initial success of V. velutina …
Guidance for the risk assessment of the presence at low level of genetically modified plant material in imported food and feed under Regulation (EC) …
2017
Abstract This document provides guidance for the risk assessment under Regulation (EC) No 1829/2003 of the unintended, adventitious or technically unavoidable presence in food and feed of low level of genetically modified plant material intended for markets other than in the European Union. In this context, the presence at low level is defined to be maximum 0.9% of genetically modified plant material per ingredient. This guidance is intended to assist applicants by indicating which scientific requirements of Annex II of Regulation (EU) No 503/2013 are considered necessary for the risk assessment of the presence at low levels of genetically modified plant material in food and feed.
Lack of specialist nidicoles as a characteristic of mite assemblages inhabiting nests of the ground-nesting wood warbler, Phylloscopus sibilatrix (Av…
2021
AbstractBird and mammal nests provide microhabitats that support a range of other species, including invertebrates. However, the variation between communities of nest-dwelling invertebrates in different nests is poorly understood. The major aim of this study was to analyze the assemblage structure of mites from the suborder Uropodina (Acari: Mesostigmata) and from superfamily Crotonioidea (Acari: Oribatida) inhabiting nests of the wood warbler, Phylloscopus sibilatrix (Aves: Passeriformes), located on a forest floor in Białowieża Forest, in eastern Poland. We also assessed the correlation between the nest material used by the birds with the assemblage structure of Uropodina mites, and compa…
2-methylthiazolidine and 4-ethylguaiacol, male sex pheromone components of the cockroach Nauphoeta cinerea (Dictyoptera, Bladeridae) : A reinvestigat…
1992
49 ref.; International audience; In Nauphoeta cinerea, male calling behavior is associated with sex pheromone release by the sternal glands. The male pheromone that attracts females from a distance is a mixture of 2-methylthiazolidine and 4-ethylguaiacol. It is active at very low concentrations, 0.05 and 0.01 ng, respectively. Two other compounds, 3-hydroxy-2-butanone and 2-methyl-2thiazoline, act at close range, keeping the female in the vicinity of the male. The function of the volatile pheromone and those of previously described contact pheromones are discussed in regard to their possible involvement in the establishment of male dominant-subordinate relationships.