125 research outputs found
Chasing the queens of the alien predator of honeybee: a water drop in the invasiveness ocean.
ABSTRACT The Yellow-legged hornet, Vespa velutina, was accidentally introduced in France in 2004, and then spread rapidly through the French territory but also to adjacent European countries (Spain, Portugal, and Belgium). During summer and autumn, V. velutina workers hunt domestic honeybees, Apis mellifera, for feeding their larvae. The impact of this alien species is mainly economic, beekeepers experiencing heavy colony losses, but also ecological, V. velutina hunting other pollinators. In their year-round life cycle, nest initiation by single queen during spring is the critical stage. In invaded areas, spring queen trapping using food baits has been promoted by apicultural unions in order to limit V. velutina population expansion. The goals of this work were 1) to evaluate the yield of this method, 2) to identify appropriate sites for trapping, 3) to identify potential optimal climatic windows of capture, and 4) to quantify the impact on local entomofauna. Our results showed that water proximity enhances trapping but not beehives proximity, and that trapping is inefficient if average week temperatures are below 10ËC. Although the trapping effect on biodiversity should be studied more carefully, spring queen trapping is highly questionable unless specific attractants could be proposed
Changes in Parasitoid Communities Over Time and Space: A Historical Case Study of the Maize Pest Ostrinia nubilalis
Understanding the ways in which human environmental modifications affect biodiversity is a key challenge in conservation planning, pest control and evolutionary ecology. Parasitoid communities, particularly those associated with agricultural pests, may be susceptible to such modifications. We document here changes in the larval parasitoid communities of Ostrinia nubilalis â the main pest of maize â and its sibling species O. scapulalis, based on two historical datasets, one collected from 1921â1928 and the other from 2001â2005. Each of these datasets encompasses several years and large geographical areas and was based on several thousands/millions of host larvae. The 80-year interval between the two datasets was marked by a decrease in O. nubilalis parasitism to about two thirds its initial level, mostly due to a decrease in the rate of parasitism by hymenopterans. However, a well balanced loss and gain of species ensured that species richness remained stable. Conversely, O. scapulalis displayed stable rates of parasitism over this period, with a decline in the species richness of its parasitoid community. Rates of parasitism and species richness in regions colonized by O. nubilalis during the 1950s were one half to one third those in regions displaying long-term colonisation by this pest. During the recent human activity-driven expansion of its range, O. nubilalis has neither captured native parasitoids nor triggered parasite spill back or spill over
European grapevine moth, Lobesia botrana Part I: biology and ecology
Though the European grapevine moth, Lobesia botrana (Denis & SchiffermĂŒller) (Lepidoptera: Tortricidae) can feed on more than forty plant species, grapevine is the preferred crop worldwide. This moth is a western palearctic species that has recently spread to Chile, Argentina, and California. The possible further expansion in other regions of the Americas is greatly feared and should be monitored carefully in the near future. In this framework, we provide an updated review of the current knowledge on its taxonomy, morphology, biology, ecology, genomics, geographic distribution, and invasiveness. Then, in the last section, we develop a research agenda pointing out significant challenges for future investigations on bio-ecology and invasion biology, which are tightly connected with the prevention and management strategie
European grapevine moth, Lobesia botrana Part II: prevention and management
Lobesia botrana (Denis & SchiffermĂŒller) (Lepidoptera: Tortricidae), commonly known as the European grapevine moth (EGVM), is a primary pest of vineyards. This article provides an updated review of its monitoring, modelling, and management tools. EGVM management strategies analysed here include insecticide-based control, insecticide resistance, side-effects (particularly those caused by the exposure to sublethal doses of pesticides), cultural control, sterile insect technique, pheromone-mediated control strategies (with special reference to pheromone-based mating disruption), biological control, and area-wide control programs. Lastly, we outline significant challenges for future EGVM research and sustainable control implementatio
Cold winter temperatures condition the egg-hatching dynamics of a grape disease vector
The leafhopper Scaphoideus titanus is the vector of a major phytoplasma grapevine disease, Flavescence dorĂ©e. The vectorâs distribution is in Eastern and Northern Europe, and its population dynamics varies as a function of vineyard latitude. We tested the hypothesis that hatching dynamics are cued by cold temperatures observed in winter. We exposed eggs from a natural population to simulated âcoldâ and âmildâ winters and varied the exposure time at 5 °C from 0 to 63 days. We show that temperature cooling mainly affected the onset of hatching and is negatively correlated to the cold time exposure. The majority of hatchings occurred more quickly in cold rather than in mild winter simulated conditions, but there was no significant difference between the duration of hatching of eggs whatever the cold time exposure. In agreement with the Northern American origin of the vector, the diapause termination and thus the timing regulation of egg hatching require cold winters
Induction natale de la prĂ©fĂ©rence pour lâhabitat (NHPI).
7 pagesNational audienc
Grape cultivar affects larval and female fitness of the European grapevine moth, Lobesia botrana (Lepidoptera: Tortricidae).
8 pagesInternational audienc
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