A note on the chronic effects of tall oil on the variegetd cutworm, Peridroma saucia [Lepidoptera : Noctuidae]

Les effets chroniques de la résine liquide (tall oil), un sous-produit de l'industrie papetière, sur le ver-gris panaché, Peridroma saucia, ont été évalués par son incorporation à une diète artificielle. À une concentration de 1,5% en poids frais de la diète, la résine liquide dépoissée a réduit significativement le poids du P. saucia, a prolongé son temps de développement et a augmenté la mortalité des divers stades. Une relation linéaire significative a été trouvée entre la concentration de résine dans la diète ettoutes les données de développement évaluées. Une expérience de changement de diète a clairement démontré que l'effet inhibiteur de la résine envers le P. saucia est persistant et n'est pas automatiquement supprimé par le transfert de larves à une diète non traitée. La résine peut être un agent de lutte naturel efficace dans la lutte au ver-gris panaché.Chronic effects of tall oil, a by-product of the kraft pulping process of softwoods, on the variegated cutworm, Peridroma saucia, were assessed via incorporation into artificial diet. At a dietary concentration of 1.5% fresh weight, depitched tall oil (DTO) significantly reduced P. saucia weight, prolonged developmental time, and increased mortality in different stages. A significant linear relationship was found between dietary concentration of DTO and ail developmental parameters tested. A diet-shift experiment clearly demonstrated that the inhibitory effect of DTO to P. saucia is persistent and not readily alleviated by transferring larvae to untreated diet. DTO may be a useful natural agent for pest management

Variation among 532 genomes unveils the origin and evolutionary history of a global insect herbivore

The diamondback moth, Plutella xylostella is a cosmopolitan pest that has evolved resistance to all classes of insecticide, and costs the world economy an estimated US $4-5 billion annually. We analyse patterns of variation among 532 P. xylostella genomes, representing a worldwide sample of 114 populations. We find evidence that suggests South America is the geographical area of origin of this species, challenging earlier hypotheses of an Old-World origin. Our analysis indicates that Plutella xylostella has experienced three major expansions across the world, mainly facilitated by European colonization and global trade. We identify genomic signatures of selection in genes related to metabolic and signaling pathways that could be evidence of environmental adaptation. This evolutionary history of P. xylostella provides insights into transoceanic movements that have enabled it to become a worldwide pest.Minsheng You … Simon W. Baxter … Christopher M. Ward … et al