Effects of Aphicides on Pecan Aphids and Their Parasitoids in Pecan Orchards

Abstract

Aphids are important pests of pecans. Traditionally, insecticides have been the primary method of management. However, over-reliance and non-judicious use has led to resistance and damage to natural enemy populations. Therefore, frequent assessment of insecticides is necessary in order to monitor resistance development and non-target impacts. Aphicides, flonicamid, sulfoxaflor, and afidopyropen were assessed for their effects on pecan aphids and parasitoid, Aphelinus perpallidus, in a mature pecan orchard in 2019 and 2020. Post-application assessments were performed 7, 14, and 21 days post-application. Leaf samples from non-treated trees had greater aphid numbers than treated trees 7 days post-application with differences diminishing throughout the other two treatment periods in 2019. In 2020, aphid numbers were lower but leaf samples from non-treated trees had more aphids than treated trees 7 days post-application in the lower canopy. These differences again diminished 14 and 21 days post-application. There was no difference among treatments in number of parasitoid adults or mummies. These findings indicate that pecan growers have multiple potential options available for aphid management that do not negatively impact the primary pecan aphid parasitoid. Implications of the results on pecan aphid management are discussed.

Functional response of Harmonia axyridis preying on Acyrthosiphon pisum nymphs: the effect of temperature

“…The broad host range, complex life cycle, and quick adaptation to new environments make it difficult to control this aphid. Moreover, this aphid may develop insecticide resistance, making its control through these means challenging 35 .…”

Characterization of Field-Evolved Resistance to Afidopyropen, a Novel Insecticidal Toxin Developed from Microbial Secondary Metabolites, in Bemisia tabaci

“…Cases pertaining to the swift reversion of resistance to chemical agents have recently been reported in various field-developed populations of insects with resistance [ 23 , 24 , 25 , 26 ]. Afidopyropen acts on the transient receptor potential vanilloid (TRPV) of sucking insects and as a modulator of the Nan-Iav vanilloid TRPV subtype, and then against a series of notorious pests [ 1 , 2 , 3 , 4 , 5 , 6 , 8 ]. This research suggests that field-developed, medium-level resistance to afidopyropen was unstable in the HD population of B. tabaci , alluding to the ability to exploit this trait in insecticide resistance management tactics.…”

“…It has been classified in accordance with IRAC as the first member of the new pyropene class of the MoA sub-group 9D, which is different from other pyridine azomethine derivatives, including pyrifluquinazon and pymetrozine (MoA sub-group 9B) [2]. Afidopyropen provides powerful effects against notorious sucking and piercing arthropods, such as soybean aphids, pecan aphids, whiteflies, and Asian citrus psyllids, including those that have evolved resistance to other popular chemical agents [3][4][5][6]. Similar to pymetrozine, afidopyropen controls the sucking of insect pests by Toxins 2022, 14, 453 2 of 9 disturbing their coordination and ability to feed.…”

Salivazo Clastoptera achatina Germar (Hemiptera: Clastopteridae) en nogal Pecanero: Fluctuación poblacional, distribución y eficacia de insecticidas

“…En tanto que Spinetoram presentó efectividad constante del 100% para el control de C. achatina a las 72 h y 7 días después de su aplicación, pero sus efectos sobre insectos no objetivo parasitoides y depredadores puede variar según la especie, ya que algunos autores reportan mortalidades de moderadas a altas en parasitoides (García y Tarango 2011, Sheikh et al 2018, mientras que en depredadores puede ser baja o nula como en Chrysopa sp. y coccinélidos, los cuales son importantes para el control de C. achatina y otras plagas del nogal (Aguilar 2014, Visnupriya y Muthukrishnan 2017, Slusher et al 2021. Por último, el menor efecto de control se observó con novaluron en ambas dosis (5 y 10 g de i. a.…”