metallic wood-boring beetle

(Agrilus obsoletoguttatus)

Conservation Status
metallic wood-boring beetle (Agrilus obsoletoguttatus)
Photo by Alfredo Colon
  IUCN Red List

not listed

     
  NatureServe

NNR - Unranked

     
  Minnesota

not listed

     
           
           
           
 
Description
 
 

Agrilus obsoletoguttatus is a metallic wood-boring beetle. It is common in eastern United States and adjacent Canadian provinces. It is uncommon in Minnesota, where it is at the western edge of its range. It is small to medium-sized, much smaller than emerald ash borer. Adults are 3 16 to 5 16 (4.7 to 8 mm) long and bronzish-black to greenish-brown. They sometimes have a weak purple iridescence.

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 has straight sides and does not narrow in the middle. There is a distinct ridge on each side of the pronotum at the shoulder-like (humeral) region near the base of the elytrum.

The elytra are slightly narrowed before the middle and tapered beyond the middle toward the tips. The tips are separated, broadly rounded, and finely toothed. Toward the tip the inner margins are slightly elevated. There are three or four patches of yellow or white hair-like outgrowths on each elytrum and on each side of the abdomen. On the elytrum there is a round patch near the front (anterior) margin in the humeral region; a round patch toward the tip; and a short, narrow stripe in the middle toward the inner margin. The stripe is often more or less interrupted. There is often a small round patch toward the outer margin behind (posterior to) the stripe. The upper side of the abdomen is black. The last segment of the abdomen has a faint ridge on top (dorsally) but does not have a spine at the tip.

The antennae are short, extending only to about the middle of the pronotum. They are sawtoothed from the fourth segment to the tip.

The larvae are known as flat-headed wood borers. They are elongated, narrow, slightly flattened, and whitish. The first segment of the thorax is widened and has a horny, plate-like surface with a line down the middle. This widened segment is the source of the common name of wood-boring larvae, flat-head. It has no legs but has a pair of forcep-like spines at the rear end of the abdomen.

 
     
 

Size

 
 

Total Length: 3 16 to 5 16

 
     
 

Similar Species

 
     
     
 
Habitat
 
 

Hardwoods

 
     
 
Biology
 
 

Season

 
 

May to July

 
     
 

Behavior

 
 

 

 
     
 

Life Cycle

 
 

 

 
     
 

Larva Food

 
 

Roots, trunks, and branches of hardwoods, including birch, elm, ironwood, maple, oak, and walnut

 
     
 

Adult Food

 
 

Leaves of the same plants as the larvae

 
     
 
Distribution
 
 

Distribution Map

 

Sources

24, 27, 29, 30.

 
  10/30/2018      
         
 

Occurrence

 
 

Uncommon in Minnesota

 
         
 
Taxonomy
 
 

Order

Coleoptera (beetles)  
 

Suborder

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

Infraorder

Elateriformia  
 

Superfamily

Buprestoidea (metallic wood boring beetles)  
 

Family

Buprestidae (metallic wood-boring beetles)  
 

Subfamily

Agrilinae (branch and leaf buprestids)  
 

Tribe

Agrilini  
  Subtribe Agrilina  
 

Genus

Agrilus  
  Subgenus Agrilus  
       
 

Synonyms

 
 

Agrilus interruptus

 
       
 

Common Names

 
 

This species has no common name. The common name of the family Buprestidae is metallic wood-boring beetles, and is applied here for convenience.

 
       

 

 

 

 

 

Glossary

Elytra

The hardened or leathery 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.

 

 

 

 

 

 
 
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Alfredo Colon

 
    metallic wood-boring beetle (Agrilus obsoletoguttatus)      
           
 
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Camera

     
 
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Metallic Wood Boring Beetles
Seth Ausubel
  Metallic Wood Boring Beetles  
 
About

Buprestidae

 
     

 

slideshow

       
 
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  Alfredo Colon
6/8/2018

Location: Woodbury, MN

metallic wood-boring beetle (Agrilus obsoletoguttatus)  
           
 
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