bluish borer

(Agrilus cyanescens)

Conservation Status
bluish borer
Photo by Babette Kis
  IUCN Red List

not listed

 
  NatureServe

NNR - Unranked

 
  Minnesota

not listed

 
           
           
           
           
           
           
           
 
Description
 
 

Bluish borer is an exotic, robust, small, wood-boring beetle. It is native to Europe and northern Asia. The first sightings in North America occurred in 1920 in Sturgeon Bay, Wisconsin, and in 1921 in Sherborn, Massachusetts. At both sightings they were reported as abundant. The beetle now occurs in the United States from Maine to Virginia, west to Minnesota and Missouri, in western Washington and Oregon, in southern Canada from New Brunswick to Manitoba, and in western British Columbia. It is uncommon in Minnesota, where it reaches the western extent of its range. Larvae hosts include honeysuckle (Lonicera spp.), snowberry (Symphoricarpos spp.), and buckthorn (Rhamnus spp.). The larvae bore under the bark and feed on the sapwood of living branches and twigs, eventually causing these parts to die. However, the beetle does not occur in large enough numbers to be considered a pest of significant concern.

Adults are 316 to 516 (5.2 to 7.8 mm) in length. The body is rigid, bullet-shaped, narrow, and long. The upper side is hairless, metallic, slightly shiny, and uniformly blue, bluish-green, bluish-violet, or rarely bronze.

The head is slightly tucked beneath the first segment of the thorax (prothorax). The antennae are short and have 11 segments. Segments 4 through 11 are sawtoothed. Segments 7 to 11 are as long as wide. The mouthparts are projected downward.

The upper plate covering the prothorax (pronotum) is wider than long, is narrowed in the middle, and has a distinct lateral margin. The lateral margin is rounded. There is no ridge on each side near the rear corners, and there is no longitudinal depression down the middle. The plate between the wing bases (scutellum) is small but visible. It is not crossed with ridges.

The abdomen has five segments. The first two segments are fused together. They are barely visible or not at all visible at the sides. The wing covers (elytra) are slightly narrowed before the middle and tapered beyond the middle toward the tips. They almost cover the entire abdomen. Toward the tip the inner margins are slightly elevated. The tips are separated and rounded. The surface is sculpted like shingles on a roof. The last segment of the abdomen does not have a distinct ridge above.

The last part of the leg (tarsus), corresponding to the foot, has 5 segments. There is a pair of claws at the tip of each tarsus.

 
     
 

Size

 
 

Total length: 3 16 to 5 16 (5.2 to 7.8 mm)

 
     
 

Similar Species

 
     
     
 
Habitat and Hosts
 
 

Honeysuckle (Lonicera spp.), snowberry (Symphoricarpos spp.), and buckthorn (Rhamnus spp.)

 
     
 
Biology
 
 

Season

 
 

May to July

 
     
 

Behavior

 
 

Adults are good fliers.

 
     
 

Life Cycle

 
 

 

 
     
 

Larva Food

 
 

Sapwood in the twigs and branches of host species

 
     
 

Adult Food

 
 

Leaves of the same plants as the larvae

 
     
 
Distribution
 
 

Distribution Map

 

Sources

24, 29, 30, 82, 83.

 
  11/21/2022      
         
 

Occurrence

 
 

 

 
         
 
Taxonomy
 
 

Order

Coleoptera (beetles)  
 

Suborder

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

Infraorder

Elateriformia  
 

Superfamily

Buprestoidea (metallic wood boring and false jewel beetles)  
 

Family

Buprestidae (metallic wood-boring beetles)  
 

Subfamily

Agrilinae  
 

Tribe

Agrilini  
  Subtribe Agrilina  
 

Genus

Agrilus  
  Subgenus Agrilus  
       
 

Subordinate Taxa

 
 

bluish borer (Agrilus cyanescens cyanescens)

bluish borer (Agrilus cyanescens johanidesi)

 
       
 

Synonyms

 
 

Agrilus amabilis

Agrilus caeruleus

Agrilus cyaneus

Agrilus fissifrons

Agrilus kyselyi

Agrilus sulcaticeps

Agrilus virens

 
       
 

Common Names

 
 

bluish borer

 

 

 

 

 

 

 

 

 

Glossary

Elytra

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

 

Pronotum

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

 

Prothorax

The first (forward) segment of the thorax on an insect, bearing the first pair of legs but not wings.

 

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.

 

 

 

 

 
 
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Babette Kis

 
 

Agrilus cyanescens bluish wood boring beetle

Agrilus cyanescens, bluish borer, at the hedgerow at Barnes Prairie, Racine Co., WI. Photo taken May 31, 2021.

  bluish borer  
 

Alfredo Colon

 
    bluish borer   bluish borer  
           
    bluish borer      
           
 
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Other Videos
 
  Metallic Wood-boring Beetle (Buprestidae: Agrilus cyanescens)
Carl Barrentine
 
   
 
About

Jun 12, 2011

Photographed at the Turtle River State Park, North Dakota (08 June 2011). Thank you to 'v belov' and T.C. MacRae (@Bugguide.net) for confirming the identity of this specimen!

 

 

Camcorder

 
 
Visitor Sightings
 
           
 

Report a sighting of this insect.

 
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  Alfredo Colon
6/2/2021

Location: Woodbury, MN

bluish borer  
  Alfredo Colon
6/1/2021

Location: Woodbury, MN

bluish borer  
  Babette Kis
5/31/2021

Location: Barnes Prairie, Racine Co., WI

bluish borer  
           
 
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Created: 11/21/2022

Last Updated:

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