Bioactivator insecticides for Coffeea arabica L. and toxic to Leucoptera coffeella (Lepidoptera: Lyonetiidae)

Abstract

The insecticides used on coffee plants can function as bioactivators for this species and be utilized to manage Leucoptera coffeella. Thus, the objectives were to verify the bioactivation action on the morphophysiology of the coffee plant and its toxicity to L. coffeella. The treatments were dinotefuran + flutriafol 450 SC, dinotefuran + pyriproxyfen (100 + 25) EW, imidacloprid 700 WG, flupyradifurone 200 SL, thiamethoxam 250 WG, thiamethoxam + cyproconazole 600 WG, and control (water). The physiology of coffee seedlings was evaluated at 10, 20, and 40 days after application (DAA) of the insecticides. Analyses of biometric variables for aerial and root development of seedlings and survival of L. coffeella larvae were conducted at 10, 20, 40, 60, and 80 DAA. The insecticides did not alter the physiological parameters evaluated in the seedlings at 10, 20, and 40 DAA. At 60 and 80 DAA, height and leaf area were lower in seedlings treated with imidacloprid. The dry matter of the stem in seedlings treated with imidacloprid was lower than in other treatments. The volume and area of the roots of the seedlings at 80 DAA were higher in those that received the insecticide thiamethoxam 250 WG. All insecticides were toxic to L. coffeella larvae at all evaluation dates. The insecticides did not have bioactivator properties for aerial development. Thiamethoxam 250 WG has a bioactivator effect on root volume and area. The insecticides protect seedlings from infestation up to 80 DAA.