Efficacy of Insecticides against the Invasive Apricot Aphid, Myzus mumecola

SIMPLE SUMMARY: The apricot aphid (Myzus mumecola Matsumura) is native to Asia and is currently spreading throughout Europe. As this aphid species causes substantial damage to apricot trees, it is important to assess the effectiveness of available insecticides. In this study, we examined 12 different insecticides according to the maximum field dose. To determine the efficacy of each insecticide, aphids were exposed to treated leaf discs of apricot and mortality rates were evaluated at various doses. Additionally, the impact on the colony development was assessed for selected insecticides. Furthermore, we conducted a field trial for insecticides commonly applied in apricot production. In laboratory trials, acetamiprid, deltamethrin, etofenprox, flupyradifurone, pirimicarb, sulfoxaflor, and tau-fluvalinate insecticides resulted in mortality rates ranging from 95% to 100% at the field dose. In the colony development trials, flonicamid, pyrethrins, and spirotetramat exhibited a strong effect. Furthermore, spinosad and azadirachtin demonstrated the least efficacy in reducing the colony development of surviving nymphs per aphid. Based on these findings, it can be concluded that most of the tested insecticides can be used to effectively control M. mumecola. ABSTRACT: The invasive apricot aphid (Myzus mumecola Matsumura) is an important pest of apricot trees (Prunus armeniaca L.). In the presented study, laboratory bioassays using treated leaf disks of apricot were conducted to test the efficacy of twelve insecticides according to the maximum field dose. Additionally, dose-response curves were established for selected insecticides, and the effects on colony development were evaluated. Furthermore, a field trial was conducted to investigate the effectiveness of commonly used insecticides in apricot cultivation. The dose-response curves showed LC(50) values ranging from 0.08 mg/L for flupyradifurone, 0.15 mg/L for acetamiprid, 0.70 mg/L for etofenprox, 1.89 mg/L for sulfoxaflor, 2.64 mg/L for pirimicarb, 3.97 mg/L for deltamethrin, up to 6.79 mg/L for tau-fluvalinate. These aforementioned insecticides resulted in mortality rates ranging from 95 to 100% at the field dose. Azadirachtin, flonicamid, and pyrethrins showed mortality rates of 27 to 45%. Spirotetramat reduced the colony development and decreased the number of infested shoots by 86%. Spinosad, which is not recommended against aphids, showed minimal impact; reducing the number of exuviae in nymphs in the colony development bioassay. It can be concluded that the majority of the tested insecticides are effective against M. mumecola.