Skip to content Skip to navigation
UMass Collegiate M The University of Massachusetts Amherst
  • Visit
  • Apply
  • Give
  • Search UMass.edu
Center for Agriculture, Food, and the Environment
UMass Extension Vegetable Program
  • Vegetable Home
  • About
    • About the Vegetable Program
    • Faculty & Staff
    • Funding
    • Request a visit
    • Request a Crop & Pest Management Planning Meeting
    • Contact us
  • Publications
    • Vegetable Notes
    • New England Vegetable Management Guide
    • Northeast Vegetable and Strawberry Pest Identification Guide
    • Cucurbit Disease Scouting & Management Guide
    • Sweet Corn IPM Scouting Guide & Record Keeping Book
    • Nutrient Management Guide for New England Vegetable Production
  • Fact Sheets
  • Special Topics
    • Brassica Pest Collaborative
    • Heating Greenhouses with Locally Grown Corn
    • Winter Production and Storage
  • Resources
    • Food Safety for Farmers
    • Nutrient Management
    • Scouting Resources
    • Research Reports
    • Recursos en Español (Spanish-Language Resources)
    • Useful Links
  • Services
    • Disease Diagnostics
    • Soil and Plant Nutrient Testing
    • UMass Extension Bookstore
    • Hot Water Seed Treatment
    • Mentor Farm Program
    • Scouting Program
  • News & Events
    • Upcoming Events
    • News
    • Past Events
  • Make a Gift

Cucumber Beetle, Spotted

Image
Spotted cucumber beetle. Photo: S. Ellis, Bugwood.org
Image
Spotted cucumber beetle. Photo: W. Cranshaw, Colorado State University, Bugwood.org

Diabrotica undecimpunctata howardi

Life Cycle:

Adults overwinter in field edges near last year’s crop, with a small proportion remaining in the field. With the onset of warm days, beetles move rapidly into young crops. Adults cause direct feeding damage to cotyledons, leaves and the base of the stem. Eggs are laid in soil and larvae feed on roots. After the pupal stage is completed in the soil, summer adults emerge. These adult beetles congregate in flowers and may cause damage to fruit.

Monitoring & Thresholds:

Beetle feeding spreads bacterial wilt to young plants,especially before the 5-leaf stage. Cucumber and muskmelon are highly susceptible to wilt; watermelon is not. To prevent bacterial wilt in susceptible crops, scout for beetles twice weekly at the seedling stage. Treat when beetle numbers reach 1 beetle per 2 plants.

Cultural Controls & Prevention:

  • Use crop rotation to reduce beetle numbers.
  • Transplant crops instead of direct seeding to allow plants to reach a later growth stage before beetles arrive.
  • Use a perimeter trap crop of Blue Hubbard or another Cucurbita maxima variety and treat borders with a systemic insecticide at planting or with a foliar insecticide as soon as the first beetles arrive, to protect a main crop of cucumbers and melons from beetle damage.
  • Spunbonded row covers exclude beetles; use hoops to prevent abrasion and remove at flowering to allow pollination.
  • Some repellents or systemics may be applied to transplants outside the greenhouse before setting in the field, which is convenient and allows lower rates of application.

For current information on production methods (including varieties, spacing, seeding, and fertility), weed, disease, and insect management, please visit the New England Vegetable Management Guide website.

Crops that are affected by this insect:

  • Cucumber, Muskmelon, and Watermelon
  • Pumpkin, Squash, and Gourds
Last Updated: January 14, 2013

The Center for Agriculture, Food and the Environment and UMass Extension are equal opportunity providers and employers, United States Department of Agriculture cooperating. Contact your local Extension office for information on disability accommodations. Contact the State Center Director’s Office if you have concerns related to discrimination, 413-545-4800 or see ag.umass.edu/civil-rights-information.

Ways to Connect

  • Ask a question
  • Request a Visit
  • Request a Crop & Pest Management Planning Session
  • Submit a Sample
  • Become a Mentor Farm
  • Join the NEVBGA
  • Make a Donation

Connect with us on Social Media

extension vegetable program facebook page  extension vegetable program instagram   extension vegetable program youtube channel

Center for Agriculture, Food, and the Environment

 

Stockbridge Hall,
80 Campus Center Way
University of Massachusetts Amherst
Amherst, MA 01003-9246
Phone: (413) 545-4800
Fax: (413) 545-6555
ag [at] cns [dot] umass [dot] edu (ag[at]cns[dot]umass[dot]edu)

 

Civil Rights and Non-Discrimination Information

College of Natural Sciences

Login for faculty and staff

CAFE Units

Mass. Agricultural Experiment Station

UMass Extension

UMass Research and Education Center Farms

UMass Cranberry Station

Water Resources Research Center

Interest Areas

Agriculture

Commercial Horticulture

Energy

Environmental Conservation

Food Science

Nutrition

Water

Youth Development & 4-H

Services

Pesticide Education

Plant Diagnostics Laboratory

Soil and Plant Nutrient Testing Laboratory

Hot Water Seed Treatment

Water Testing / Environmental Analysis Laboratory

Projects

Conservation Assessment Prioritization System (CAPS)

Extension Risk Management/Crop Insurance Education

Mass. Envirothon

Mass. Herp Atlas

Mass. Keystone

MassWoods

North American Aquatic Connectivity Collaborative

RiverSmart

UMass Design Center in Springfield

Resources

Extension Sales Portal

Agriculture & Commercial Horticulture Resources

Community & Economic Vitality

Disaster Preparedness

Food Safety

Home Lawn & Garden

Integrated Pest Management (IPM)

Land Conservation Tools

Pollinators

Tick testing

Resources for Faculty and Staff

Extension Programs

4-H Youth Development

Agriculture

Crops, Dairy, Livestock and Equine

Fruit

Greenhouse Crops and Floriculture

Landscape, Nursery and Urban Forestry

Pesticide Education

Turf

Vegetable

Clean Energy

Climate Change

Food Science

Nutrition Education

Value-Added Food

Seal of The University of Massachusetts Amherst - 1863
©2025 University of Massachusetts Amherst · Site Policies · Accessibility