Holes in my nuts.

[Graham K]

I have a decent size Cob Nut tree in the garden that has produced a good harvest this year (6 or 7lbs) of nuts. However quite a few of the nuts have tiny round holes in them (see photo). There were also quite a few earwigs mixed in with the nuts and a couple of maggots, small and white with reddy/brown heads. The nuts with the holes are empty inside.

Are the maggots "baby" earwigs chewing their way out or are the earwigs chewing their way in?

Graham.

[Two_Sheds]

sounds like a weevil of some sort. I'll have a google

[Two_Sheds]

how's this? (scroll down the page of the link) Technical Information

and:
http://www.probertencyclopaedia.com/...eevil&offset=0

“Cobnuts grow in clusters of one to five...In some years ...they’re also prone to weevils, so, again, you have to inspect them individually.” http://www.timesonline.co.uk/tol/lif...cle4786434.ece

[Nicos]

Spot on 2sheds!- we have nut weevil in our hazelnuts too!

[Graham K]

Sounds spot on, but what if anything can I do about it?

[Two_Sheds]

nothing much.
It's one of things that's worse in certain years, it seems

[Graham K]

Ask a silly question! Can weevils fly?

I've read that they will infect the same tree for years given half a chance, ie nut falls to ground, maggot crawls out, digs in and climes back up a year or two later.

If so grease bands (the ones for fruit trees) should stop them?

[Nicos]

Yes they can according to this...

"The results of the present study are contrary to previous reports suggesting that most adult pecan weevils fly to the pecan trunk after emergence from the soil; however, our results did indicate that a proportion of the population flies directly from the orchard floor into the pecan canopy and thus would circumvent strategies that attempt to control weevils moving up the trunk."

It is talking about pecan weevils- but they are similar.

also....they seem to prefer to crawl...

"Movement of adult pecan weevils crawling and flying to the host trunk, flying to the host canopy, crawling within the host canopy and flying between host trees was studied using four types of passive traps over four seasons. Each type of trap was used to capture weevils at different locations on or near the tree and to discriminate flying versus crawling behaviour.

3 More pecan weevils crawl to the trunk than fly and a proportion of the population flies directly from the orchard floor into the pecan canopy. The majority of this movement occurs at dusk.

4 The vertical distribution of weevils was generally uniform throughout the canopy but more weevils were captured in suspended traps nearest tree tops, rather than traps near the ground, when flying between trees and this was significantly so for two of 4 years."


Also have a look at this about shaking the tree if you don't want to spray it...

http://www.ca.uky.edu/entomology/ent...tpdf/ef206.pdf


I think I'll grease band mine next summer!

[Nicos]

One hazel nut weevil can damage up to 200 nuts!!

http://www.cost850.ch/publications/2...ing_report.pdf

[Graham K]

Ok the ones with wings are going to screw us whatever but the lazy crawling ones are going to come to a very sticky end, ha ha ha, got the buggers!

[BFG]

If they overwinter in the soil, would turning it over in the winter to expose them to the elements/birds work?

[Nicos]

Problem with my tree is that there are loads of trunks!!!!

[Snadger]

Sounds painful..............

[Graham K]

Same with mine, ten seperate trunks. It's a pain in the rear but each one now has it's own band. I've made sure that all of the bands are ABOVE any point where the trunks can touch so no jumping from one to the other when the wind blows!

[Nicos]

Ah ha!!!..you're determined to stop them aren't ya????

It'll be interesting to see what happens by this time next year!!

Good luck!