Spotted Cucumber Beetle
Diabrotica undecimpunctata
Hosts
Spotted cucumber beetle adult.
Damage to foliage caused by cucumber beetle feeding.
- 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,
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