spotted cucumber beetle

(Diabrotica undecimpunctata)

Conservation Status
spotted cucumber beetle
Photo by Babette Kis
  IUCN Red List

not listed

 
  NatureServe

NNR - Unranked

 
  Minnesota

not listed

 
           
           
           
           
           
           
 
Description
 
 

Spotted cucumber beetle is a small skeletonizing leaf beetle. It occurs throughout the United States, in Mexico, and in southern Canada. It is common in Minnesota. It is found in fields, including agricultural fields. The larva feeds on the roots of corn, plants in the Cucurbitaceae (cucumber) family, and other plants. The adult feeds on the flowers, leaves, stems, and fruit of a more than 200 species of plants. As they feed they create holes in the leaves, scars on the stems, and pinholes on the fruit. They transmit bacterial and viral diseases. Spotted cucumber beetle is a vector for at least five plant diseases. It is a major pest to agricultural crops. Because of the wide variety of plants it damages it is considered one of the ten worst insect pests.

The body is oval, 316 to 516 (4.6 to 7.7 mm) long, and (2.8 to 3.9 mm) wide. When viewed from above, the head and most of the legs are clearly visible.

The head is black. The antennae are thread-like and long, more than half as long as the body. They have 11 segments. The first segment (scape), second segment (pedicel), and third segment (first flagelomere) are yellow. The remaining 8 segments are black. The antennae are close together at the base, about level with the middle of the eyes. They are flexible, and can project in various directions. The eyes are not notched.

The exoskeletal plate covering the thorax (pronotum) is rectangular, wider than the head, and and narrower than the base of the hardened wing covers (elytra). It is colored differently than the elytra, yellow to yellowish-red with no black markings.

The elytra are greenish-yellow, hairless, and long, concealing the entire abdomen. They have a distinct, narrowly flattened margin. There are six bold black spots on each elytron. The plate between the wing bases (scutellum) is small, triangular, and black.

The legs are mostly black. The base of the third leg segment (femur) is yellow. The last part of each leg (tarsus), corresponding to the foot, has five segments. However, the fourth segment is minute and is concealed within the heart-shaped lobes at the end of the third segment, making it appear that there are only four segments. The last segment has a pair of claws.

 
     
 

Size

 
 

Total length: 316 to 516 (4.6 to 7.7 mm)

 
     
 

Similar Species

 
     
     
 
Habitat
 
 

Fields, agricultural fields

 
     
 
Biology
 
 

Season

 
 

April to October

 
     
 

Behavior

 
 

 

 
     
 

Life Cycle

 
 

 

 
     
 

Larva Food

 
 

Roots of corn, plants in the Cucurbitaceae (cucumber) family, and other plants.

 
     
 

Adult Food

 
 

Flowers, leaves, stems, and fruit of a wide variety of plants.

 
     
 
Distribution
 
 

Distribution Map

 

Sources

7, 24, 27, 29, 30, 82.

 
  10/12/2022      
         
 

Occurrence

 
 

Common

 
         
 
Taxonomy
 
 

Order

Coleoptera (beetles)  
 

Suborder

Polyphaga (water, rove, scarab, long-horned, leaf, and snout beetles)  
 

Infraorder

Cucujiformia  
 

Superfamily

Chrysomeloidea (leaf beetles and allies)  
 

Family

Chrysomelidae (leaf beetles)  
 

Subfamily

Galerucinae (skeletonizing leaf and flea beetles)  
 

Tribe

Luperini  
  Subtribe Diabroticina  
 

Section

Diabroticites  
  Genus Diabrotica (cucumber beetles)  
       
 

Subordinate Taxa

 
 

spotted cucumber beetle (Diabrotica undecimpunctata howardi)

western cucumber beetle (Diabrotica undecimpunctata tenella)

western spotted cucumber beetle (Diabrotica undecimpunctata undecimpunctata)

 
       
 

Synonyms

 
 

 

 
       
 

Common Names

 
 

southern corn rootworm (larva)

spotted cucumber beetle (adult)

 

 

 

 

 

 

 

 

 

Glossary

Elytra

The hardened or leathery forewings of beetles used to protect the fragile hindwings, which are used for flying. Singular: elytron.

 

Femur

On insects and arachnids, the third, largest, most robust segment of the leg, coming immediately before the tibia. On humans, the thigh bone.

 

Pronotum

The exoskeletal plate on the upper side of the first segment of the thorax of an insect.

 

Scutellum

The exoskeletal plate covering the rearward (posterior) part of the middle segment of the thorax in some insects. In Coleoptera, Hemiptera, and Homoptera, the dorsal, often triangular plate behind the pronotum and between the bases of the front wings. In Diptera, the exoskeletal plate between the abdomen and the thorax.

 

Tarsus

On insects, the last two to five subdivisions of the leg, attached to the tibia; the foot. On spiders, the last segment of the leg. Plural: tarsi.

 

 

 

 

 

 
 
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Alfredo Colon

 
    spotted cucumber beetle      
           
    spotted cucumber beetle   spotted cucumber beetle  
 

Babette Kis

 
 

Diabrotica undecimpunctata spotted cucumber beetle

This common beetle is easily identified and a favorite among children due to its bright colors.

Spotted cucumber beetle on dandelion Barnes Prairie 8 30 2021

  spotted cucumber beetle  
           
 

Spotted cucumber beetle on goldenrod Barnes Prairie 10 5 2022

  spotted cucumber beetle  
 

Alfredo Colon

 
    spotted cucumber beetle   spotted cucumber beetle  
           
 
MinnesotaSeasons.com Photos
 
 

 

 
           

 

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Visitor Videos
 
       
 

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Visitor Sightings
 
           
 

Report a sighting of this insect.

 
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  Alfredo Colon
8/15/2022

Location: Albany, NY

spotted cucumber beetle  
  Babette Kis
10/5/2022

Location: Barnes Prairie, Racine Co., WI

Spotted cucumber beetle on dandelion Barnes Prairie 8 30 2021

spotted cucumber beetle  
  Babette Kis
8/30/2021

Location: Barnes Prairie, Racine Co., WI

Spotted cucumber beetle on goldenrod Barnes Prairie 10 5 2022

spotted cucumber beetle  
  Alfredo Colon
8/28 or 8/29/2019

Location: Woodbury, Minnesota

spotted cucumber beetle  
  Alfredo Colon
8/13/2019

Location: Woodbury, Minnesota

spotted cucumber beetle  
           
 
MinnesotaSeasons.com Sightings
 
   

 

 

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Created: 9/24/2020

Last Updated:

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