The effect of cover crops on the abundance and survival of beneficial stink bugs

Project Overview

Project Type: Graduate Student
Funds awarded in 2015: $11,916.00
Projected End Date: 12/31/2016
Grant Recipient: University of Maryland
Region: Northeast
State: Maryland
Graduate Student:
Faculty Advisor:
Dr. Cerruti R. R. Hooks
University of Maryland

Annual Reports


  • Agronomic: clovers, rye
  • Vegetables: eggplant


  • Crop Production: conservation tillage, cover crops, cropping systems, intercropping, multiple cropping, no-till, strip tillage
  • Education and Training: extension
  • Pest Management: biological control, integrated pest management, mulches - general, mulches - killed, mulches - living, mulching - vegetative, physical control, precision herbicide use
  • Production Systems: agroecosystems, organic agriculture

    Proposal abstract:

    Eggplant, Solanum melongena L., is a favored food for Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), a common insect pest capable of causing intense defoliation leading to extreme yield loss. Eggplant is often grown on small farms where long distance crop rotation isn’t always feasible. Previous work has shown increasing the diversity of eggplant habitats with straw or winter cover crops can slow CPB invasion, reduce their numbers, and increase predator density. To take full advantage of cover crop use ineggplant requires understanding how its presence influences two common predatory stink bugs, Perillus bioculatus (Fabricius) and Podisus maculiventris (Say), which feed on CPB. While these are voracious predators, their numbers are greatly suppressed by wasps which parasitize their eggs. These wasps use a variety of chemical and environmental cues to locate stink bug eggs and their searching behavior may be disrupted by cover crop presence. This project will allow us to extend our current research in eggplant fields and specifically examine how different cover crop treatments impact: 1) the density of predatory stink bugs, 2) rates of predatory stink bug egg predation and parasitism, and 3) the identity of common parasitoids attacking predatory stink bugs in eggplant fields. Findings from this study will be used to help create new sustainable pest management strategies for eggplant growers throughout the Northeast. The ultimate goal is to reduce input cost and subsequently increase economic returns for eggplant growers who face substantial yield loss from CPB.

    Project objectives from proposal:

    1.Measure the effect of different cover crop treatments on the abundance of beneficial stink bugs, and how abundances change throughout the season. Do some treatments increase their populations? How does their population change in different treatment plots throughout the season?

    2.Determine the effect of different cover crop treatments on stink bug egg mortality due to parasitoid wasps and predators. Do some treatments decrease parasitism and predation rates? How do parasitism and predation rates change throughout the season?

    3.Assess the total number and species composition of parasitoids present in eggplant fields. What species occur and in what numbers? Does species diversity change throughout the season?

    4.To create and disseminate an effective pest management strategy to stakeholders. How can farmers maximize their economic output with sustainable practices?

    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.