Population suppression of phylloxera gallicolae and radicicolae forms on grapevines with the use of synthetic insecticides

The grapevine phylloxera Daktulosphaira vitifoliae (Fitch, 1856) is the main insect pest of viticulture globally. Infestations can occur in the aerial part of the plant (gallicolae form) and roots (radicicolae form). In this study, the effect of insecticides on the populations suppression of the gall and root forms of phylloxera one vine was evaluated. For the gallicolous form, the thiamethoxam (Actara 250 WG®, 40g c.p./100L-1), flupyradifurone (Sivanto® Prime 200 SL, 75mL c.p./100L-1), and sulfoxaflor (Closer® SC, 40mL c.p./100L-1) were evaluated in the field, under natural infestation, using rootstock plants ‘Paulsen 1103’ (Vitis berlandieri x V. rupestris). For the root stage, an experiment was carried out in a greenhouse using rooted seedlings of ‘Cabernet Sauvignon’ (Vitis vinifera) grown in pots artificially infested with 200 phylloxera eggs per plant. After 80 days of infestation, the thiamethoxam (0.2g p.c./plant), flupyradifurone (0.8mL p.c./plant), sulfoxaflor (0.3mL/plant) and imidacloprid (Proved 200 SC, 0.7 mL/plant) were applied via drench. For the gallicolae form, an application of the flupyradifurone provided a gall reduction of 90% at 28 days after the first application (DAFA). While for thiamethoxam, 3 applications were needed at weekly intervals to maintain the same level of control. For sulfoxaflor, a second application at 14 DAFA was necessary to provide a level of control above 90%. For the root stage, the insecticides sulfoxaflor and imidacloprid showed the best results, with 96 and 89% of control over nymphs and adults, respectively. The insecticides flupiradifurone and sulfoxaflor are suitable for the chemical control of phylloxera in the vine.