Resistance of Nasonovia ribisnigri (Homoptera : Aphididae) to five insecticides

International audienceSeveral strains of Nasonovia ribisnigri (Mosley) collected near Perpignan (south of France) and Almeria (south of Spain) were bioassayed and compared with a reference susceptible strain from The Netherlands. Resistance to 5 tested insecticides was observed in 2 strains. The highest resistances recorded were 680-fold for endosulfan, 26-fold for deltamethrin, 62-fold for pirimicarb, 46-fold for methomyl, and. Ii-fold for acephate. These results are discussed in relation to the possible mechanisms of resistance present in the different N. ribisnigri strains and to potential control strategies

Mechanisms of insecticide resistance in the aphid Nasonovia ribisnigri (Mosley) (Homoptera : Aphididae) from France

Nasonovia ribisnigri, a main pest of salad crops, has developed resistance to Various insecticides in southern France, including the carbamate pirimicarb and the cyclodiene endosulfan, two insecticides widely used to control this aphid. Here we have investigated the mechanisms of resistance to these two insecticides by studying cross-resistance, synergism, activity of detoxifying enzymes, and possible modifications of the target proteins. Resistance to pirimicarb was shown to be mainly due to a decreased sensitivity of the target acetylcholinesterase; this modification confered also, resistance to propoxur but not to methomyl and the two tested organophosphates (acephate and paraoxon). Endosulfan resistance was associated with a moderate level of resistance to dieldrin, and resistance to both insecticides was due, in part, to increased detoxification by glutathione S-transferases (GST). The endosulfan resistant strain displayed the same amino acid at position 302 of the Rdl gene (GABA receptor) as susceptible aphids (e.g. Ala), indicating that the Ala to Ser (or to Gly) mutation observed among dieldrin resistant strains of other insect species was not present

Towards new sources of resistance to the currant-lettuce aphid (Nasonovia ribisnigri)

Domesticated lettuce varieties encompass much morphological variation across a range of crop type groups, with large collections of cultivars and landrace accessions maintained in genebanks. Additional variation not captured during domestication, present in ancestral wild relatives, represents a potentially rich source of alleles that can deliver to sustainable crop production. However, these large collections are difficult and costly to screen for many agronomically important traits. In this paper, we describe the generation of a diversity collection of 96 lettuce and wild species accessions that are amenable to routine phenotypic analysis and their genotypic characterization with a panel of 682 newly developed expressed sequence tag (EST)-linked KASP™ single nucleotide polymorphism (SNP) markers that are anchored to the draft Lactuca sativa genome assembly. To exemplify the utility of these resources, we screened the collection for putative sources of resistance to currant-lettuce aphid (Nasonovia ribisnigri) and carried out association analyses to look for potential SNPs linked to resistance