Oak Processionary Moth

[Heston]

Heston,

Even though OPM is widespread over the entire country with the exception of the Wadden islands, in The Netherlands (and Western Germany), OPM has been confined to solitary oaks and/or oaks in lanes or along roadsides with poorly developed tree species specific ecosystems and soil food webs with a lack of tree species specific symbiotic ectomycorrhizal macrofungi caused by ammonia deposition and air and water polution, which makes the trees less capable of defending their leaves against OPM and other insects because of incomplete assimilation (lowered levels of acid and tannine production) in the base of the trunk.

This far, natural oak woodlands with intact tree species specific ecosystems have hardly been affected to not affected at all.

 

Thanks a lot for that - I find it reassuring.

As I understand it most of the UK problem has been in solitary trees and parkland and in the oakland scrub that has developed next to railway and tube lines. I had thought that the big oaks and density of planting in Richmond Park around Star and Garter would have had been established long enough to have approximated a decent natural woodland - but I am probably wrong. Certainly London does have appalling air quality (and not getting better at any reasonable rate).

 

Anyone got any news of the Pangbourne attack (where one might expect less pollution and more intact ecosytems) ?

[Fungus]

From laboratory research and fields experiments is known, that the larvae of the Common green lacewing (Chrysoperla carnea) eat all kinds of insects and their caterpillars or larvae. In The Netherlands, last year the killing and consuming of OPM caterpillars by the larvae of C. carnea was documented, after which close to my home a field experiment was started to determine whether the larvae can be used for bringing down the numbers of OPM caterpillars. Once the results are made public, I'll keep you all posted.

The photo shows the not before documented fatal encounter between a green lacewing larva and a female Hollyhock weevil (Rhopalapion longirostre).

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[David Humphries]

From laboratory research and fields experiments is known, that the larvae of the Common green lacewing (Chrysoperla carnea) eat all kinds of insects and their caterpillars or larvae. In The Netherlands, last year the killing and consuming of OPM caterpillars by the larvae of C. carnea was documented, after which close to my home a field experiment was started to determine whether the larvae can be used for bringing down the numbers of OPM caterpillars. Once the results are made public, I'll keep you all posted.

The photo shows the not before documented fatal encounter between a green lacewing larva and a female Hollyhock weevil (Rhopalapion longirostre).

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Very interesting developement

 

Thanks for updating Gerrit.

 

 

 

 

Great shot, btw

 

 

Bug Wars

 

 

 

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[Fungus]

Very interesting developement. Thanks for updating.

 

I can also update you on another field experiment with insect parasitic nematodes in the same region with very promising results. The nematodes, which were dissolved in water and sprayed on the OPM nests, killed about 60 % of the caterpillars. There was one location where the result even was 100 %. To avoid the nematodes also killing caterpillars of other butterfly or moth species, the spraying should take place before the month of May.

[Tony Croft aka hamadryad]

I can also update you on another field experiment with insect parasitic nematodes in the same region with very promising results. The nematodes, which were dissolved in water and sprayed on the OPM nests, killed about 60 % of the caterpillars. There was one location where the result even was 100 %. To avoid the nematodes also killing caterpillars of other butterfly or moth species, the spraying should take place before the month of May.

 

as always your contribution is on another level,

[Heston]

A nice pic of the caterpillar's face as the second image at

 

Super-strength microscope produces stunning images | Mail Online

[janey]

A nice pic of the caterpillar's face as the second image at

 

Super-strength microscope produces stunning images | Mail Online

 

Almost as good as my Sony camera 'phone

[Scottie]

Can you explain what you mean by 'instar'.

[janey]

Can you explain what you mean by 'instar'.

 

Instar refers to the stages of development caterpillars go through. They can only increase in size by shedding their skins and they do this typically five to six times (I think) between hatching and before they shed for the last time to form a pupa.

[David Humphries]

FC have just reported a 'new' outbreak in West Wickham (Bromley) which is 9 miles from the original out break in West London.

 

They're currently investigating how the new infestation has developed, whether its natural spread or affected material (oak brash) which may have been transported between sites.

 

 

New outbreak of oak processionary moth reported | Login | Horticulture Week

 

 

 

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