willow pinecone gall midge

(Rabdophaga strobiloides)

               
Conservation Status

IUCN Red List

not yet assessed

willow pinecone gall midge

NatureServe

not listed

Minnesota

not listed

Occurrence

Common

Flight/Season

One brood per year in Minnesota

Habitat

Anywhere its host species are found

Size

about 3 16 long


Identification

This gall midge is a small, about 3 16 long fly.

It is most often identified by the conspicuous and distinctive gall that houses the growing larva. The gall appears at the end of a willow stem. It consists of numerous, stunted, overlapping, loosely appressed, scale-like leaves. In the summer it is green, more or less globular, and densely covered with long, white, matted and tangled, woolly hairs. In the fall the cone turns brown and the shape resembles a pine cone.

 
Similar
Species

This is the only midge that forms pinecone-shaped galls at the tips of willow stems.


Larval Hosts

Many species of willow

 
Adult Food

 

 
Life Cycle

Adults emerge on warm days in late April or May. The female lays eggs singly on the leaves and stems near the stem tips of a host plant. The egg hatches in early May and the larva crawls to the tip of the stem. It then burrows into the soft tissue at the base of the tip of the shoot. It emits a chemical that causes the shoot tip to develop abnormally. The shoot ceases to elongate and instead produces numerous overlapping leaves that envelope the larva. The loosely overlapping leaves allow up to 31 other species of insects to deposit their eggs, including beetles, moths, sawflies, cypnid wasps, midges, and grasshoppers.

The larva pupates inside the gall and overwinters as a pupa. It produces high levels of glycerin which allows it to survive even harsh winters. In the spring a young midge emerges.

 
Behavior

 


Distribution Distribution Map  

Sources: 7, 29, 30.


Comments

 


Taxonomy

Order:

Diptera (gnats, mosquitoes, true flies)

 

Suborder:

Nematocera (long-horned flies)

 

Infraorder:

Bibionomorpha

 

Superfamily:

Sciaroidea (fungus gnats and gall midges)

 

Family:

Cecidomyiidae (gall gnats, gall midges, cécidomyidés)

 

Subfamily:

Cecidomyiinae (gall midges)

  Supertribe:

Lasiopteridi

 

Tribe:

Oligotrophini

 
Synonyms

Cecidomyia salicisstrobiloides

Cecidomyia strobiloides

Rabdophaga strobilina

 
Common
Names

willow pinecone gall midge


 

 

 

 

 

Glossary

midge

A small fly, somewhat resembling a mosquito, in one of several families in the suborder Nematocera.

 

 

 

 

 

 

 

       

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Habitat

  willow pinecone gall midge    
       

Gall

  willow pinecone gall midge   willow pinecone gall midge
       
  willow pinecone gall midge   willow pinecone gall midge
       
       

 

Camera

     

Slideshows

   
  Willow Pinecone Gall Midge (Rabdophaga strobiloides)
Andree Reno Sanborn
 
  Willow Pinecone Gall Midge (Rabdophaga strobiloides)  

 

slideshow

     

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Other Videos

 
  Willow Pine Cone Gall ,Griffith Indiana
Christopher Stokes
 
   
 
About

Published on Jul 28, 2013

A variety of insect species induce galls on host plants. Several studies have implicated phytohormones in insect-induced gall formation. However, it has not been determined whether insects can synthesize phytohormones. It has also never been established that phytohormones function in gall tissues. Liquid chromatography and tandem mass spectrometry (LC/MS/MS) were used to analyse concentrations of endogenous cytokinins and the active auxin IAA in the gall-inducing sawfly (Pontania sp.) and its host plant, Salix japonica. Feeding experiments demonstrated the ability of sawfly larvae to synthesize IAA from tryptophan. Gene expression analysis was used to characterize hormonal signalling in galls. Sawfly larvae contain high concentrations of IAA and t-zeatin, and produce IAA from tryptophan. The glands of adult sawflies, the contents of which are injected into leaves upon oviposition and are involved in the initial stages of gall formation, contain an extraordinarily high concentration of t-zeatin riboside. Transcript levels of some auxin- and cytokinin-responsive genes are significantly higher in gall tissue than in leaves. The abnormally high concentration of t-zeatin riboside in the glands strongly suggests that the sawfly can synthesize cytokinins as well as IAA. Gene expression profiles indicate high levels of auxin and cytokinin activities in growing galls.

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  Willow Pine Cone Gall ,Griffith Indiana
Christopher Stokes
 
   
 
About

Published on Jul 23, 2013

sharing what i seen today with you.
if you have some time
please leave a comment below.
and Please Subscribe to my channel

and thank you very much for watching my videos..

pictures of Griffith IN here
http://christopherphoto.blogspot.com/

Visit Griffith Indiana's Nature on facebook
http://www.facebook.com/GriffithIndianasNaturePhotos

join me on Google+
http://plus.google.com/112815794394767726853

Join me on Twitter
http://twitter.com/griffithindiana

 
     

 

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