Resumen de Egg development and toxicity of insecticides to eggs, neonate larvae and adults of Xylotrechus arvicola, a pest in Iberian grapevines

Álvaro Rodríguez González, Horacio J. Peláez Rivera, Sara Mayo Prieto, Óscar González López, Pedro Antonio Casquero Luelmo

• Xylotrechus arvicola (Coleoptera: Cerambycidae) is a xylophagous species that is becoming an important pest in vineyards in the Iberian Peninsula. The most sensitive stages are adult and egg, but their neonate larvae can also be attacked during the first 24 hours since the eggs hatch and before entering the wood. Adults were evaluated for seven days against the insecticides spinosad, Beauveria bassiana, imidacloprid and chlorpyrifos and neonate larvae (<24h) and eggs of different ages against the described insecticides, as well flufenoxuron and pyriproxyfen. All insecticides were applied in Potter tower at maximum and minimum commercial dose, showing significant diferences both among insecticides as between the applied doses. Most of the hatching occurs eight days after oviposition by X. arvicola females. Chlorpyrifos had a quick and total control of eggs of different age, neonate larvae and adults in both dose applied, but its effectiveness cause serious effects on other non-target species. Over eggs of different age, pyriproxifen had the best ovicidal control when the age of eggs increases and B. bassiana also had a good ovicidal control, due its capacity to invade the eggs actively through their shell and proliferate inside them. On neonate larvae, both doses of flufenoxuron and pyriproxyfen obtained a larval control higher than 92.0%. Biological insecticides such as B. bassiana and spinosad, with a total control on adults and good rates of mortality of neonate larvae (88% and 84%) and eggs (higher than 80.0%) can be a great instrument to biologically control this pest.