The invasion of Europe by the western corn rootworm, North America's most destructive pest, is ongoing and represents a serious threat to European agriculture. Because this pest was initially introduced in Central Europe, it believed that subsequent outbreaks Western originated from area. Using model-based Bayesian analyses genetic variability we demonstrate belief false: There have been at least three independent introductions America during past two decades. This result raises questions...

Abstract Biological control requires specific tools for the accurate detection and identification of natural enemies, to detect unusual variations in their density, which may follow changes agricultural practices. Here we have developed molecular markers Lydella thompsoni (Herting) Pseudoperichaeta nigrolineata (Walker) (Diptera: Tachinidae) within European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). Primers amplifying fragments mitochondrial COI gene were designed...

Bacillus thuringiensis has been widely used for 40 years as a safe biopesticide controlling agricultural pests and mosquitoes because it produces insecticidal crystal proteins. However, spores have also shown to contribute overall entomopathogenicity. Here, the opportunistic properties of acrystalliferous B. Cry− cereus strains were investigated in an insect species, Galleria mellonella, mammal, BALB/c mice. In both animal models, pathogenicity two bacterial species was similar. Mutant...

CRISPR gene drive has recently been proposed as a promising technology for population management, including in conservation genetics. The technique would consist releasing genetically engineered individuals that are designed to rapidly propagate desired mutation or transgene into wild populations. Potential applications biology include the control of invasive pest populations threaten biodiversity (eradication and suppression drives), introduction beneficial mutations endangered (rescue...

Abstract Genetic changes conferring adaptation to a new environment may induce fitness cost in the previous environment. Although this prediction has been verified laboratory conditions, few studies have tried document directly natural populations. Here, we evaluated pleiotropic effects of insecticide resistance on putative components mosquito Culex pipiens. Experiments using different larval densities were performed during summer two breeding sites. Two loci that possess alleles...

Although a growing body of work supports the plausibility sympatric speciation in animals, practical difficulties directly quantifying reproductive isolation between diverging taxa remain an obstacle to analyzing this process. We used combination genetic and biogeochemical markers produce direct field estimate assortative mating phytophagous insect populations. show that individuals same species, European corn borer Ostrinia nubilalis, develop on different host plants can display almost...

Adaptation to different environments may be a powerful source of genetic differentiation between populations. The biological traits selected in each environment can pleiotropically induce assortative mating individuals these genetically differentiated This situation facilitate sympatric speciation. Successful host shifts phytophagous insects provide some the best evidence for ecological speciation that occurs, or has occurred, sympatry. European corn borer, Ostrinia nubilalis (Lepidoptera:...

Two factors that can affect genetic load, synergistic epistasis and sexual selection, were investigated in Drosophila melanogaster. A set of five chromosomal regions containing visible recessive mutations put together all combinations to create a full 32 homozygous lines fixed for different numbers known mutations. measures fitness made each line: productivity (a combined measure fecundity egg‐to‐adult survivorship) competitive male mating success. Productivity, but not success, showed...

ABSTRACT We used multilocus sequence typing (MLST) to characterize phylogenetic relationships for a collection of Bacillus cereus group strains isolated from forest soil in the Paris area during mild winter. This contains multiple same sample and samples different sites. characterized 115 this 19 other based on sequences clpC , dinB gdpD panC purF yhfL loci. The number alleles ranged 36 53, total 93 allelic profiles or types were distinguished. identified three major strain clusters—C, T,...

Pyrethroid insecticides induce an excito-repellent effect that reduces contact between humans and mosquitoes. Insecticide use is expected to lower the risk of pathogen transmission, particularly when impregnated on long-lasting treated bednets. When applied at low doses, pyrethroids have a toxic effect, however development pyrethroid resistance in several mosquito species may jeopardize these beneficial effects. The need find additional compounds, either kill disease-carrying mosquitoes or...

In this study, we evaluated in field trials the effects on non-target species, of transgenic corn producing Cry1Ab toxin Bacillus thuringiensis (Bt). 1998, collected Ostrinia nubilalis (Hübner) larvae from Bt (Novartis Hybrid 176) and non-Bt at four geographical sites. We found a significant variation parasitism by tachinids Lydella thompsoni (Herting) Pseudoperichaeta nigrolineata (Walker) among sites, more than fields. The effect did not vary significantly 1999, performed experiment two...

Fixation of adaptive mutations in populations is often constrained by pleiotropic fitness costs. The evolutionary pathways that compensate such disadvantages are either the occurrence modifier genes or replacement allele less costly ones. In this context, 23 years evolution insecticide resistance mosquito Culex pipiens from southern France analyzed. aim study to answer following points. Is there a cost associated with these natural populations? Does proceed through selection modifiers? And...

ABSTRACT Little is known about genetic exchanges in natural populations of bacteria the spore-forming Bacillus cereus group, because no population genetics studies have been performed with local sympatric populations. We isolated strains thuringiensis and B. from small samples soil collected at same time two separate geographical sites, one within forest other edge forest. A total 100 98 were characterized by electrophoresis to determine allelic composition nine enzymatic loci. observed...

Two acetylcholinesterases (AChEs), AChE1 and AChE2, differing in substrate specificity some aspects of inhibitor sensitivity, have been characterized the mosquito Culex pipiens. The results ultracentrifugation sucrose gradients nondenaturing gel electrophoresis AChE activity peak fractions show that each is present as two molecular forms: one amphiphilic dimer possessing a glycolipid anchor hydrophilic does not interact with detergents. Treatment by phosphatidylinositol-specific...

Resistance to toxicants is a convenient model for investigating whether adaptive changes are associated with pleiotropic fitness costs. Despite the voluminous literature devoted this subject, intraspecific comparisons among toxicant resistance genes rare. We report here results on effect adult survival of Culex pipiens mutants involved in same adaptation: organophosphorus insecticides. This field study was performed southern France where four sequentially appeared and increased frequency...