Twig Galls, Now What?

[ElmArtTch]

I have a live oak with lots of twig galls. With the research that I have done it says that I am supposed to do nothing? When I am I supposed to do "something" or if anything at all? I have attached a picture of one of the branches.

 

[John Paul Sanborn]

There are some chemical controls available, but with large trees it becomes problematic. Drift from the spray may get into neighoboring properties, which is against the law.

I'm not too familliarwith the pest, so I don't know if soil sytemics like Metasystox will work on it, and that stuff is nasty.

One option is to get some soil work done to improve the trees habitat. Often when pests reach infestation levels, the soil is not as good as it should be. If it is in turf grass, this is very common.

Get a soil test done by a competant arborist or horticulturalist. have some vertical mulching or radial trenching done and mulch properly.

Often simple cultural practices can turn an infestation around.

 

[ROLLACOSTA]

the gall i can see in the pic looks like one made by a parositic wasp...some people think they are unsightly i personaly like them
large trees should be looked at as a reef ie a host for all types of flora and fauna..some good some bad galls should be left alone as there rarely treatable and arnt harmfull to your tree..

 

[John Paul Sanborn]

Usually they are not a problem, but the can become a secondary stress that causes throws the tree into a decline. since the galls can girdle twigs

Callirhytis
Description 1/8-1/4" (3-5 mm). Brown to reddish brown. Abdomen compressed on sides. Short "waist." Antennae threadlike. Legs stout. Wings transparent.

Food Adult may drink nectar. Larva feeds on soft tissues inside galls on live oak twigs and leaves.

Life Cycle These gall wasps have 2 different generations a year. The 1st consists of females that reproduce parthenogenetically, or asexually. The 2nd generation consists of males and females that reproduce sexually. The asexual generation produces stem galls on 1 oak species and the sexual generation produces leaf galls on another oak species. Galls grow to the size of small apples. Fully grown larvae pupate in central chambers inside the galls.

 

[ROLLACOSTA]

in the uk we do not get galls anywhere like this [pictured] or not that ive seen ..we usualy get wasp galls, nail galls ,small flat leaf galls..

 

[John Paul Sanborn]

Ive seen trees with fine tip decline and lots of sprouting With galls)

I've usually been able to associate it with long term lawn care. Too much N and irregation.

 

[Kneejerk Bombas]

You could trunk inject Bidrin, of course the galls will always be there, the treatment needs to be done three years straight, you'll have injuries from the injection holes and phytotoxicity at the injecton sites.

 

[Guy Meilleur]

Originally posted by ElmArtTch
When I am I supposed to do "something" or if anything at all?

1. Prune out all galls on dead branches.

2. Prune out galls on dying and severely infested branches. destroy all debris, to break life cycle.

3. Relieve stress on tree--invigorate roots, control other problems.

Yes these wasps are generally beneficial, but on a tree with other big problems they can be the last straw. A big red oak at a VA college was severely topped, and Callyrhitis galls are now girdling every twig. There is no cure.

So yes, 'Do Nothing" may work, but if there are a lot of them, treatment is warranted, and they may be a symptom of other issues the host has.