oak rough bulletgall wasp

(Disholcaspis quercusmamma)

Conservation Status
oak rough bulletgall wasp
 
  IUCN Red List

not listed

 
  NatureServe

not listed

 
  Minnesota

not listed

 
           
           
           
 
Description
 
 

Oak rough bulletgall wasp is a cynipid gall wasp. It is usually identified by the gall it produces. In Minnesota, galls are found in clusters on the twigs and branches of bur oak and swamp white oak. They first appear as green bumps on the twig. The bumps later turn bright red. As they grow into round galls, they turn light brown and are soft. Eventually, they turn dark brown and harden. Mature galls are 5 16 to in diameter, woody, and spherical, with a nipple-like, obscure point at the top. They produce honeydew that attracts bees, and wasps, and ants, which protect the gall wasp from other parasitic wasps. Each gall contains only a single wasp, though they may be shared by other species (inquilines). A small, circular hole in the side of a gall indicates where the wasp has emerged.

The galls remain on the tree up to five years after the wasp has left the gall. They do not kill the host stem but will reduce the growth of the infested tree.

 
     
 

Size

 
 

Galls: 5 16 to in diameter

 
     
 

Similar Species

 
     
     
 
Habitat
 
 

Anywhere the host species are found

 
     
 
Biology
 
 

Season

 
 

One generation per year, late October to early November

 
     
 

Behavior

 
 

 

 
     
 

Life Cycle

 
 

The life cycle of this wasp involves alternation of generations, one generation with only asexual females and one generation with both sexual males and sexual females. Information is only available for the asexual generation. The sexual generation has not been described in entomological literature.

The female lays eggs in a dormant, terminal bud at the tip of a twig. In the late spring of the following year, the larva stimulates the growing stem to produce a gall in which the wasp develops. The larva pupates within a small cell in the center of the gall. In Minnesota, adults emerge in September. In the asexual generation, both winged and wingless females are produced. Males are unknown.

 
     
 

Larva Hosts

 
 

bur oak, swamp white oak

 
     
 

Adult Food

 
 

Adult wasps do not feed

 
     
 
Distribution
 
 

Distribution Map

 

Sources

7, 24, 27, 30, 82, 83.

 
  2/28/2023      
         
 

Occurrence

 
 

Common

 
         
 
Taxonomy
 
 

Order

Hymenoptera (ants, bees, wasps, and sawflies)  
 

Suborder

Apocrita (narrow-waisted wasps, ants, and bees)  
  Infraorder Proctotrupomorpha  
 

Superfamily

Cynipoidea (gall wasps and allies)  
 

Family

Cynipidae (gall wasps)  
 

Subfamily

Cynipinae  
  Tribe Cynipini (oak gall wasps)  
 

Genus

Disholcaspis  
       
 

Synonyms

 
 

Disholcaspis mamma

 
       
 

Common Names

 
 

oak rough bulletgall wasp

 

 

 

 

 

 

 

Glossary

Inquiline

An animal that lives in the nest of an animal of another species.

 
 
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Babette Kis

 
 

Oak rough bulletgall wasp

Many galls on this particular bur oak, which was sapling size.

  oak rough bulletgall wasp  
           
 
MinnesotaSeasons.com Photos
 
    oak rough bulletgall wasp   oak rough bulletgall wasp  
           
    oak rough bulletgall wasp   oak rough bulletgall wasp  
           
    oak rough bulletgall wasp   oak rough bulletgall wasp  
           
    oak rough bulletgall wasp   oak rough bulletgall wasp  

 

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  Babette Kis
10/13/2020

Location: hedgerow at Barnes Prairie, Racine Co., WI

Many galls on this particular bur oak, which was sapling size.

oak rough bulletgall wasp  
           
 
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Created 3/18/2019

Last Updated:

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