Spotted Cucumber Beetle

Diabrotica undecimpunctata

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Hosts

spotted cucumber beetle adult on leaf Spotted cucumber beetle adult.

feeding damage on foliage
Damage to foliage caused by cucumber beetle feeding. 

larvae feeding on root Spotted cucumber beetle larva feeding on a bean root.

larvae in soil
Spotted cucumber beetle larvae.

  • Hemp
  • Beans
  • Corn
  • Cucurbits
  • Potato
  • Tomato
  • Small grains
  • Ornamentals
  • Grasses
  • Weeds

Description

Adults have a black head, legs, and antennae. They have ovoid yellow-green bodies with 12 black spots on the wings. Larvae occur in the soil, and are not known to feed on hemp roots. They are about 8-12 mm, worm-like, yellowish-white, and the head and last segment of the body are dark brown to black.

Life Cycle

Egg | Larva | Pupa | Adult

  • 2 generations per season.
  • Overwinter as adults in protected outdoor areas.
  • Adults lay eggs near host plants (grasses, cucurbits, legumes) and feed on roots in the soil.
  • Pupation occurs in the soil about 2 months after egg hatch.
  • Adults can be present, feeding on hemp leaves,
Damaging Lifestage(s): Adult

Damage Symptoms

In hemp, adults chew on leaves, creating irregular-shaped holes. Damage is considered minor. 

Time for Concern

Entire growing season, but especially when plants are small.

When and Where to Scout

Adults become active at temperatures above 50°F in the spring. Look for adults on stems, leaves, and flowers.

Threat Level

Low.

Occurrence in Utah

Not yet found as a damaging pest in field-grown hemp.

General Management

  • Keep crop area weed free.
  • Use plastic or organic mulches and drip irrigation.
  • Destroy crop residues after harvest.

When to Consider Treatment

When two or more beetles are found per plant on 25% of plants.

Look-alikes

Western corn rootworm; northern corn root worm, other yellow and black leaf beetles (Coleoptera: Chrysomelidae)

Insecticides

Utah-Registered Product Active Ingredient(s) Notes
Aza-Direct Biological Insecticide azadirachtin  
AzaGuard azadirachtin  
AzaSol azadirachtin  
Azatin O Biological Insecticide azadirachtin  
Azatrol EC Insecticide azadirachtin  
Azera Insecticide azadirachtin  
Bayer Advanced NATRIA Insecticidal
Soap Ready-To-Use
potassium laurate  
Bonide All Seasons Horticultural & Dormant Spray Oil Concentrate; Ready to Spray mineral oil  
Bonide Diatomaceous Earth Crawling Insect Killer diatomaceous earth Greenhouse use only.
Bonide Rose Rx 3 in 1 Concentrate  clarified hydrophobic extract of neem oil Greenhouse use only.
Botanigard Maxx pyrethrins Greenhouse use only.
Brandt Ecotec Plus rosemary oil Greenhouse use only.
Bug Buster-O Extinguish Ant Bait pyrethrins Greenhouse use only.
Deadzone diatomaceous earth  
Dr. Earth Final Stop OMRI Fruit Tree Insect Killer (RTU); Concentrate rosemary oil Outdoor use only
Dr. Earth Final Stop OMRI Rose and Flower Insect Killer (RTU) rosemary oil Ground application only to non-blooming plants.
Dr. Earth Final Stop OMRI Vegetable Garden Insect Killer (RTU); Concentrate  rosemary oil Only on non-blooming plants.
Dr. Earth Final Stop OMRI Yard and Garden Insect Killer (RTU); Concentrate rosemary oil  
Dr. Earth Final Stop ProActive Yard & Garden Insect Killer (spray) rosemary oil  
EcoWorks EC neem oil, cold pressed  
Evergreen Crop Protection EC 60-6 pyrethrins  
Ferti-lome Fruit Tree Spray pyrethrins  
Grandevo CG; WDG Chromobacterium sub
strain praa4-1 cells
 
Leaf Life Gavicide Green 415 mineral oil Greenhouse use only or transplants intended for field planting.
Mite-E-Oil mineral oil Greenhouse use only
Molt-X azadirachtin  
Natural Guard Brand Neem clarified hydrophobic extract of neem oil Only for outdoor use, or transplants intended for outdoor fields.
Neemix 4.5 Insect Growth Regulator azadirachtin  
Ortho Tree & Shrub Fruit Tree Spray Concentrate clarified hydrophobic extract of neem oil  
Pycana pyrethrins Greenhouse use only.
Pyganic Crop Protection EC 1.4 II; 5.0 II  pyrethrins  
Pyrethrum TR Total Release Insecticide pyrethrins  
Rango neem oil, cold pressed Use prior to flowering.
Safer Brand #567 Pyrethrin & Insecticidal Soap Concentrate II potassium salts of fatty acids Use prior to flowering.
Safer Brand Neem Oil Concentrate clarified hydrophobic
extract of neem oil
 
Safer Brand Yard & Garden Insect Killer II potassium salts of fatty acids  
Surround WP Crop Protectant kaolin  
Tersus Insecticide pyrethrins  
TriTek mineral oil  
Whitney Farms Insecticidal Soap potassium laurate  
Xpectro OD pyrethrins  

Photo Credits

  • Adult - USU Extension IPM Program
  • Damage - Gerald Holmes, California Polytechnic State University at San Luis Obispo, Bugwood.org
  • Larvae - John C. French Sr., Retired, Universities: Auburn, GA, Clemson and U of MO, Bugwood.org

Precautionary Statement: Utah State University and its employees are not responsible for the use, misuse, or damage caused by application or misapplication of products or information mentioned in this document. All pesticides are labeled with ingredients, instructions, and risks, and not all are registered for edible crops. “Restricted use” pesticides may only be applied by a licensed applicator. The pesticide applicator is legally responsible for proper use. USU makes no endorsement of the products listed in this publication.