bumble bee mimic robber fly

(Laphria posticata)

               
Conservation Status

IUCN Red List

not yet assessed

bumble bee mimic robber fly (Laphria posticata)

NatureServe

NNR - Unranked

Minnesota

not listed

Occurrence

 

Flight/Season

June through August

Habitat

Woodlands and woodland edges

Size

Total Length: ½ to 11 16

         
         
         
          Photo by Luciearl

Identification

This is a small to medium-sized, robust, robber fly. The thorax and abdomen are partially covered with long yellow hairs making it resemble a bumble bee. It is thought to be a mimic of golden northern bumble bee (Bombus fervidus). Adults are½ to 11 16 long

The thorax is stout, black, and evenly covered with long yellow hairs. There is a tuft of black hairs in front of the wings and a tuft of mostly yellow hairs with a few black hairs in front of the balancing organs (halteres). The hairs on exoskeletal plate between the abdomen and the thorax (scutellum) are black.

On the male, abdominal segment (tergite) 1 is entirely covered with black hairs; tergite 2 has a patch of yellow hairs on the trailing edge (posterior) at each side of the upper surface (dorsolateral); tergite 3 has a similar but larger patch; tergite 4 is completely covered with yellow hairs; tergite 5 is covered by yellow hairs except for the forward (anterior) middle part, which has black hairs; tergites 6 and 7 are entirely covered with black hairs. The female is similar except tergites 1 and 2 are entirely black, and only tergite 3 has yellow dorsolateral patches.

There are two large compound eyes and three small simple eyes (ocelli). The compound eyes extend above the level of the top of the head (vertex), making the head appear hollowed out between the eyes when viewed from the front. The ocelli are arranged in a triangle on a prominent rounded projection (tubercle) in the middle of the head between the compound eyes. The upper face has long, yellow, erect hairs. There is a cluster of forward-directed bristles (a “beard”) on the lower part of the face. The beard on males is entirely yellow. On females there are yellow hairs at the upper margin of the beard, black hairs below. The hairs below the sucking mouth part (proboscis) are yellow on the male, black on the female. The antennae have 3 segments. The third segment is elongated.

The legs are stout and spiny. On the male, the third segment (femur) of the hind leg has a weak line of yellow hairs above (dorsally) and below (ventrally). On the female these are all black. The fourth segment (tibia) of the front and middle legs are covered with long hairs. On the female, these are all black. On the male, the hairs on the front (anterior) side are black, those on the back (posterior) side are yellow. On the female they are all black. The hind tibia of both sexes have all black hairs.

The last segment of the foot (tarsus) has 2 pads.

The above description refers to the nominate subspecies L. p. posticata. The other subspecies that may be found in Minnesota is L. p. scutellaris. It has yellow or golden-yellow hairs on the margin of the scutellum and on the upper surface of the hind tibia. Tergite 6 is covered with yellow hairs.

 
Similar
Species

 


Larval Food

 

 
Adult Food

Flying insects, including bees, wasps, beetles, and other robber flies

 
Life Cycle

 

 
Behavior

 


Distribution Distribution Map  

Sources: 24, 27, 29, 30.


Comments

Large Family
With 7,003 species in 530 genera worldwide, robber flies are one of the largest and most abundant families of insects alive today. Bee-like robber flies, as their name suggests, resemble bees. There are 240 species of bee-like robber flies, 62 species in North America north of Mexico.

No Common Name
Few of the North American Laphria species have a common name. The common name for the genus is bee-like robber fly. Laphria sacrator is one of several species famous for being a bumble bee mimic, so “bumble bee mimic robber fly” will stand in for the common name.


Taxonomy

Order:

Diptera (gnats, mosquitoes, true flies)

 

Suborder:

Brachycera (circular-seamed flies, mouches muscoïdes, muscoid flies, short-horned flies)

 

Infraorder:

Muscomorpha

 

Superfamily:

Asiloidea

 

Family:

Asilidae (robber flies)

 

Subfamily:

Laphriinae

 

Tribe:

Laphriini

 
Subordinate Taxa

bumble bee mimic robber fly (Laphria brunnea) (questionable)

bumble bee mimic robber fly (Laphria posticata posticata)

bumble bee mimic robber fly (Laphria scutellaris) (?)

 
Synonyms

Bombomima brunnea

Bombomima scutellaris

 
Common
Names

no common name


 

 

 

 

 

Glossary

Femur

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

 

Halteres

In flies: a pair of knob-like structures on the thorax representing hind wings that are used for balance.

 

Ocellus

Simple eye; an eye with a single lens. Plural: ocelli.

 

Proboscis

The protruding mouthparts of a sucking 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.

 

Tergum; tergite

The upper (dorsal), hardened plate on a segment of the thorax or abdomen of an arthropod. Plural: terga.

 

Tarsus

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

 

Tibia

The fourth segment of an insect leg, after the femur and before the tarsus (foot).

 

Vertex

The upper surface of an insect’s head.

 

 

 

 

 

       

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Luciearl


Robber Fly having a meal

  bumble bee mimic robber fly (Laphria posticata)    

       
       
       

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Steve Collins
 
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Luciearl
6/27/2018

Location: Cass County

Robber Fly having a meal

bumble bee mimic robber fly (Laphria posticata)


     
     
 

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