Aphid Parasitism: A Sustainable BioControl Option Against Aphid Pests of Pecans in the Southeastern U.S.

Project Overview

GS19-197
Project Type: Graduate Student
Funds awarded in 2019: $14,740.00
Projected End Date: 08/31/2021
Grant Recipient: University of Georgia
Region: Southern
State: Georgia
Graduate Student:
Eddie Slusher
Email
Major Professor:
Dr. Jason Schmidt
Email
University of Georgia

Commodities

  • Nuts: pecans

Practices

  • Pest Management: biological control, integrated pest management

    Proposal abstract:

    Pecan ranks in the top 10 commodities in Georgia with a farm gate value of $401 million in 2017. Like most agricultural production, pecans are threatened by attacks from insect pests. One key pest that concerns pecan growers and often times requires control are aphids, particularly, yellow aphids and black pecan aphids. Yellow pecan aphids can produce a considerable amount of honeydew, which promote sooty mold growth on foliage, negatively affecting the photosynthetic activity of the leaves. Black aphid feeding causes leaf chlorosis and, under heavy infestation, leaf defoliation. Growers normally respond to aphid pressure by spraying synthetic insecticides, which can negatively affect natural enemy populations and increases the risk of developing insecticide resistance, while only temporarily relieving the problem.

    Therefore, there is a need for ecologically based methods of managing aphid populations such as biological control using parasitic wasps. Parasitic wasps are known to attack pecan aphids in Georgia but research is needed to investigate the relationships between yellow and black pecan aphids and their parasitoids.

    Our objectives include: 1. identifying the parasitoid species attacking pecan aphids in Georgia and quantifying their parasitism rates; 2. assessing parasitism rates on pecan aphids in the laboratory; and 3. examining the relationship between canopy height and parasitism rates. We will sample aphids and collect parasitized aphids to quantify parasitism rates. We will deploy yellow sticky cards to survey for adult parasitoid populations. Adult parasitoids will be identified accordingly. Results will provide better understanding on how parasitoids contribute to aphid regulation and inform management decisions.

    Project objectives from proposal:

    Our objectives include:

    1. identifying the parasitoid species attacking pecan aphids in Georgia and quantifying their parasitism rates;

    2. assessing parasitism rates on pecan aphids in the laboratory; and

    3. examining the relationship between canopy height and parasitism rates.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.