Integrating Cover Crops into Blueberry Production for Sustainable Japanese Beetle Control

Project Overview

Project Type: Graduate Student
Funds awarded in 2002: $10,000.00
Projected End Date: 12/31/2004
Matching Federal Funds: $175,324.00
Matching Non-Federal Funds: $10,000.00
Region: North Central
State: Michigan
Graduate Student:
Faculty Advisor:

Annual Reports


  • Fruits: berries (other)


  • Crop Production: cover crops
  • Education and Training: extension
  • Pest Management: cultural control, integrated pest management, row covers (for pests)


    A comparison of different acid-tolerant ground covers in highbush blueberry determined that row middle covers influence the abundance of Japanese beetle, Popillia japonica Newman, (Coleoptera: Scarabaeidae) adults and larvae. Buckwheat was more attractive to adults, but fewer larvae were found in these plots compared to ryegrass and clover. More Japanese beetles were found in all planted row middles than those with bare ground. Most timings of row-middle cultivation caused a reduction in P. japonica larval density, although patterns were not consistent across two years. These results indicate that cultural control can reduce the likelihood of P. japonica becoming established in fields, and that cultivation and cover crops should be integrated into perennial fruit production to minimize the potential for economic impact by this pest. Results of the research were presented to blueberry growers at summer and winter meetings and a fact sheet has been published to inform growers of the latest research results on Japanese beetle management.


    The Japanese beetle, Popillia japonica Newman, (Coleoptera: Scarabaeidae) is an invasive insect with potential for range expansion into many of the major agricultural production regions of the USA (ALLSOPP, 1996). P. japonica is currently the most important pest for producers of highbush blueberry, Vaccinium corymbosum L., in the Midwestern United States (ANON., 2001; ISAACS et al., 2004). It is a univoltine insect, with greatest adult abundance from mid-July to August (FLEMING, 1972), when beetles feed on leaf tissue and ripe blueberry fruits. If beetles are not controlled, fruit can be contaminated when harvesting machines knock beetles off the bushes. Over 70% of Michigan’s 7,285 ha of blueberry crop is harvested mechanically (KLEWENO and MATTHEWS, 2002), and because the market demands fruit completely free of insect contamination, strategies are needed to minimize the risk of adult beetles being present during harvest. Foliar insecticide applications continue to be the foundation of P. japonica management in blueberries and many other fruit crops, as growers strive to meet exacting quality standards. Additional strategies targeting larvae, which develop in the soil, may help growers reduce populations of P. japonica within infested blueberry production regions and minimize the risk of beetles spreading into uninfested areas. Such strategies could also have the long-term benefit of reducing the number of foliar applications of insecticides.

    Project objectives:

    Test the impact of acid-tolerant cover crops on Japanese beetle establishment in blueberries.

    Investigate the effect of cultivation timing on larval density in row middles of blueberry.

    Demonstrate sustainable approaches of Japanese beetle suppression to the blueberry industry.

    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.