locust borer

(Megacyllene robiniae)

               
Conservation Status

IUCN Red List

not listed

locust borer

NatureServe

NNR - Unranked

Minnesota

not listed

Occurrence

Common

Flight/Season

August to October

Habitat

Wherever black locust has been planted

Size

Total Length: 716 to 1 (11 to 28 mm)

          Photo by Alfredo Colon
 
Identification

Locust borer is a large, colorful, round-necked long-horned beetle. It is native to the Appalachian and Ozark regions of the eastern United States, where its larval host, black locust, is also native. Black locust has been widely cultivated as an ornamental and as a soil improver in restorations. As the tree spread across North America, locust borer went with it. Locust borer is now common in Minnesota. Larvae develop within the stems of their host and are rarely seen. Adults are seen during the day from August to October on goldenrods. It is considered a serious pest of black locust. The wood of infected trees is commercially worthless, and the infected trees may die.

Adults are 716 to 1 (11 to 28 mm) long and are densely covered with short, velvety hairs. They are jet black with numerous bright yellow bands and spots, looking something like a wasp or hornet. This is probably an example of Batesian mimicry, making the beetle appear unpalatable to potential predators. The body is constricted between the thorax and the abdomen, forming a distinct rounded “neck”.

The head is black with three yellow bands. The face is slanted forward, not vertical. The small antennae-like structures (palps) emerging from the lower jaws (maxillae) are blunt at the tip, not pointed. The antennae are long, at least half as long as the body. The base of each antenna is surrounded by the compound eye.

The exoskeletal plate covering the thorax (pronotum) is black, rounded, and widest near the middle when viewed from above, strongly convex when viewed from the side. It is black with yellow front, rear, and lateral margins, and two narrow yellow bands.

The hardened forewings (elytra) are black with seven narrow yellow bands. The third band is strongly W-shaped. The inner one-third of each elytron is abruptly depressed.

The legs are reddish.

 
Similar
Species

Painted hickory borer (Megacyllene caryae) appears nearly identical but the adult emerges in the spring. It has not been recorded in Minnesota.

 
Larval Food

Black locust

 
Adult Food

Goldenrod flower pollen

 
Life Cycle

 

 
Behavior

Adults are active during the day

 
Distribution Distribution Map  

Sources: 24, 27, 29, 30, 82.

 
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:

Cerambycidae (long-horned beetles)

 

Subfamily:

Cerambycinae (round-necked long-horns)

 

Tribe:

Clytini

 

Genus:

Megacyllene

 
Synonyms

Megacyllene flexuosum

Megacyllene pictus

 
Common
Names

locust borer

 

 

 

 

 

Glossary

Elytra

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

 

Maxillae

Paired mouth structures of arthropods located immediately behind the mandible and used for tasting and manipulating food.

 

Palp

Short for pedipalp. A segmented, finger-like process of an arthropod; one is attached to each maxilla and two are attached to the labium. They function as sense organs in spiders and weapons in scorpions. Plural: palpi.

 

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
       
  locust borer   locust borer
       
  locust borer   locust borer
       
MinnesotaSeasons.com Photos
   
       
       

 

Camera

     
Slideshows
   
  Locust Borer
Andree Reno Sanborn
 
  Locust Borer  
 
About

Megacyllene robiniae

 
     

 

slideshow

       
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Other Videos
 
  Locust borer beetle eating pollen in flowers
GoTrails
 
   
 
About

Oct 6, 2019

Locust borer beetle crawling / walking and eating / feeding on pollen / nectar of bright yellow flowers of goldenrod plants | Bee-like, Wasp-like | Megacyllene robiniae, Robinia borulo, cyllène du robinier | Coleoptera, Käfer, coleópteros, escarabajos, coléoptères, coleotteri | serious pest of the black locust tree | Wildlife, Animal Behavior, Nature, Insect facts | #GoTrails, #beetle, #arthropod, #insect, #insects, #beetles, #animalforkids | HD video, nature sounds

   
       
  Locust Borer - Megacyllene robiniae
adamitshelanu
 
   
 
About

Sep 24, 2014

Locust Borer - Megacyllene robiniae

Species of the beetle:
Locust Borer
Megacyllene robiniae (Forst.)
Family: Cerambycidae

Date: 13 SEPTEMBER 2014

[vado-g3 avidemux usbmic]

   
       
  Longhorned Beetle Wasp Mimic - Locust borer
Stoil Ivanov
 
   
 
About

Sep 1, 2019

Locust borer ( Megacyllene robiniae ) Filmed on 8-31-2019 McDonald Woods Forest Preserve ,Lindenhurst Illinois. Good example of Batesian mimicry. Pest of the Black locust tree , but so beautiful.

   
       
  Locust Borer, Part 1 - August 25, 2013
Don Gagnon
 
   
 
About

Aug 26, 2013

Locust Borer (Megacyllene robiniae), Pottersville Woods, Somerset, Massachusetts, Sunday morning, August 25, 2013, 12:57 PM - Canon PowerShot SX50 HS MVI_43272; 1:11 min.

   
       

 

Camcorder

         
Visitor Sightings
   
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Alfredo Colon
8/31/2019

Location: Maplewood Nature Center

locust borer


 
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Created: 2/12/2020

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