bean leaf beetle

(Cerotoma trifurcata)

               
Conservation Status

IUCN Red List

not yet assessed

bean leaf beetle

 

NatureServe

NR - Unranked

Minnesota

not listed

Occurrence

Common

Flight/Season

One generation: Mid-May to late September

Habitat

 

Size

Total Length: to ¼

          Photo by Alfredo Colon

Identification

This is a small skeletonizing leaf beetle. It is common in North America east of the Great Plains. It is found in most soybean fields every year.

Adults are to ¼ long. The body is longer than wide and slightly convex. When viewed from above, the head and most of the legs are clearly visible.

The head is always black. The mouthparts project from the front of the head. The antennae are thread-like. The bases of the antennae are close together.

The upper thoracic shield (pronotum) and hardened wing covers (elytra) are usually yellow but may be red or any color in between. The pronotum is broad but slightly narrower that the base of the elytra. It has a distinct lateral margin and no black markings.

Each elytron has a black spot on the front (anterior) inner margin that joins with an identical spot on the opposite elytron forming a backward-pointing triangle. There are usually two large spots in the middle (mid-dorsal), one small spot near the tip (apex), and one stripe on the outer margin. The spots and stripes may be absent, but the triangle is always present.

The last part of each leg (tarsus), corresponding to the foot, has five segments but the first segment is minute, making it appear that there are only four segments.

 
Similar
Species

 


Larval Food

Roots of legumes

 
Adult Food

Leaves of legumes

 
Life Cycle

Adults overwinter in the soil. They become active in the spring when the plant seedlings first emerge and feed on the leaves that were preformed in the seed (cotyledon leaves). They remain active until the first new (neoformed) leaf unfurls. At that time the female lays small groups of orange eggs on the soil near the stems of host plants. The eggs hatch in about 11 days and the larvae begin feeding on host plant roots. In the next 35 to 55 days the larvae pass through three stages, pupate in the soil, and emerge as adults. These progeny of overwintered adults appear in the summer. They feed on mature leaves and on the green tissue of the pod wall, only occasionally eating through the wall to the bean. They do not occur in numbers large enough to cause serious crop damage.

 
Behavior

 


Distribution Distribution Map  

Sources: 24, 27, 29, 30.


Comments

 


Taxonomy

Order:

Coleoptera (beetles)

 

Suborder:

Polyphaga (water, rove, scarab, longhorn, leaf and snout beetles)

 

Infraorder:

Cucujiformia

 

Superfamily:

Chrysomeloidea (long-horned and leaf beetles)

 

Family:

Chrysomelidae (leaf beetles)

 

Subfamily:

Galerucinae (skeletonizing leaf beetles)

 

Tribe:

Luperini

 

Subtribe:

Diabroticina

 

No Rank:

Cerotomites

 
Synonyms

Chrysomela trifurcata

 
Common
Names

bean leaf beetle


 

 

 

 

 

 

 

Glossary

Elytra

The hardened forewings on an insect used to protect the fragile hindwings, which are used for flying, in beetles and true bugs.

 

Pronotum

The saddle-shaped, exoskeletal plate on the upper side of the first segment of the thorax of an insect.

 

Tarsus

The last two to five subdivisions of an insect’s leg, attached to the tibia; the foot. Plural: tarsi.

 

 

 

 

 

       

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Alfredo Colon


  bean leaf beetle    

       
       
       

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Other Videos

 
  Bean Leaf Beetle - Cerotoma trifurcata
adamitshelanu
 
   
 
About

Published on Sep 10, 2014

Bean Leaf Beetle - Cerotoma trifurcata

On the bank of the Deep River in Worthville, Randolph County, North Carolina, this farmers' pest with bright beautiful colors caught Uncle Steve's eye:

Bean Leaf Beetle
Cerotoma trifurcata
Family: Chrysomelidae; Subfamily: Galerucinae

Date: 26 AUGUST 2014

[vado-g3 avidemux]

 
     
  Soybean School - Bean Leaf Beetle
RealAgriculture
 
   
 
About

Published on Jun 12, 2018

Here's an interview with OMAFRA field entomologist Tracey Baute. We're talking the comeback of bean leaf beetle.

 
     
  Bean leaf beetle management in Ohio
The Ohio State University IPM Program
 
   
 
About

Published on Apr 24, 2018

In this video, Dr. Kelley Tilmon discusses the biology and proper way to scout for both foliar and pod injury caused by this pest in Ohio.

 
     

 

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Alfredo Colon
6/8/2018

Location: Woodbury, MN

bean leaf beetle


     
     
 

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