What makes a little hole in acorns ?

[posie]

Hello everyone.This is my first request for info, since I joined WAB .I was picking up acorns today and noticed that some were not as heavy as others. Each lighter one had ONE tiny hole in it's 'shell' , a similar size hole to a woodworm hole. Obviously they were lighter in weight because some , if not all the seed had been eaten. What is doing this , is it an 'insect' or something , eating it itself , or is it something laying eggs in each acorn , so that the larvae have food when they hatch. Thanks(in anticipation)

[loripo]

There is a weevil that does this , using acorns to 'drill'into and lay eggs for it's larvae. Hopefully someone will be able to confrim this and give more details.

[david156]

I agree with loripo. Could be Acorn Weevil (Curculio glandium), but I would wait for the expects on here too

[posie]

Thanks guys, now I can be cocky and tell everyone what it is . What is a weevil, is it a flying insect, if not , how does it get right up our trees . has it got a boring or drilling 'tool' at its muzzle,or does it use sort of gnawing teeth ? It must be tiny, to get through that little hole.Isn't nature wonderful.

[Jason Green]

Hi Posie,

Weevils are beetles. The Acorn Weevil Curculio glandium (though I'm sure others have similar habits/associations) is in the Curculionidae family, though there are about six different families of them in the UK.

Take care,

Jason

[posie]

Thanks Jason,

[loripo]

Here's a photo of one from the Gallery...
Acorn Weevil - Curculio glandium - Wildlife Photography

[posie]

I've been to Google, and OH I SEE ! the adult weevil doesn't get into the acorn , it lays it's eggs into the hole. Why didn't someone explain that.. I bet all you 'experts' were having a laugh !

[posie]

Originally Posted by posie

Thanks guys, now I can be cocky and tell everyone what it is . What is a weevil, is it a flying insect, if not , how does it get right up our trees . has it got a boring or drilling 'tool' at its muzzle,or does it use sort of gnawing teeth ? It must be tiny, to get through that little hole.Isn't nature wonderful.

why didn't anybody answer my questions ?

[solus]

Originally Posted by posie

why didn't anybody answer my questions ?

Possibly because a lot of folk are at work at the moment and maybe the "bug" people don't look in to the plant forums too much? Might be an idea to post your weevil question in the Insects and Invertebrates forum...

[posie]

Thanks for replying,but I meant last night.anyway I've found out now from google. I just felt a bit of an idiot saying how clever they are to get into such a tiny hole, when in fact they don't go in the hole, they just lay eggs in the hole.,somebody could have corrected me , but never mind ,,,,I think I am beginning to get the measure of the specialist threads.,,, POSIE.

[Paul mabbott]

Originally Posted by posie

why didn't anybody answer my questions ?

As somebody else mentioned - because many 'insect people' don't have time to look at the plant fora! Sorry, about that.

Weevils are a Superfamily of plant-eating (phytophagous) beetles which have projecting face-mouth parts (a rostrum). The rostra may be very long and thin or very short and broad (or anything in between) - they are adapted to different plants so the rostral form varies greatly between weevils boring into wood and those using softer plant parts. Perhaps you can look at the various rostral forms as different drill bits?

Some weevils fly but, like most beetles, they generally walk around. Many do not have wings and some have elytra (wing cases) that are fused and so cannot open.

They quite variable in size, colouration &c.

[loripo]

Sorry! Had been looking up things on acorns, so thought it might be weevils, but didn't want to confidently get it wrong Already done that on a recent thread

[Jason Green]

Originally Posted by posie

Thanks guys, now I can be cocky and tell everyone what it is . [1=] What is a weevil, is it a flying insect , if not , how does it get right up our trees . [=2] has it got a boring or drilling 'tool' at its muzzle ,or does it use sort of gnawing teeth ? It must be tiny, to get through that little hole.Isn't nature wonderful.

Originally Posted by loripo

There is a weevil that does this , [=2] using acorns to 'drill'into and lay eggs for it's larvae. Hopefully someone will be able to confrim this and give more details.

Originally Posted by Jason Green

Hi Posie,

[=1] Weevils are beetles. The Acorn Weevil Curculio glandium (though I'm sure others have similar habits/associations) is in the Curculionidae family, though there are about six different families of them in the UK.

Take care,

Jason

Originally Posted by posie

why didn't anybody answer my questions ?

We did! Just in a different order

[posie]

Thankyou all , I've got it now . I've started noticing more things since I've been on WAB , like insects , spiders and etc............................................ I think I'm getting the BUG ! !

[Dutchess]

WAB is catching - no doubt!

Oh, and just to add, that many people think maggots go into the apple, rather than eat their way out - so you are not alone in that way of thinking P

[posie]

I did know that maggots eat their way out, but I keep getting this image of a weevil trying to squeeze through that tiny hole to get in there to lay her eggs. Then I thought...well if she can't do that perhaps she deposits her eggs out of her 'snout'. but I now know that she straddles that tiny hole in the acorn and deposits her eggs into the cavity , through the hole , maybe she has a tube that she puts into the hole and shoots her eggs through the tube , into the acorn. I'm glad that the Human reproduction is easier ! !

[posie]

Thankyou so much Lori , that is amazing ....now I know exactly ,a specialised tool for drilling at the front end and a (is it) depositor at the rear end.Wonderful...............

[loripo]

I think it's called an ovipositor ( an egg positioner!)

[rangersarah2]

This may sound like a really stupid question, but I assure you that it is genuine. Why have you all thought weevil instead of gall wasp? What would the first sign of a gall wasp be?

[Jason Green]

Originally Posted by rangersarah2

This may sound like a really stupid question, but I assure you that it is genuine. Why have you all thought weevil instead of gall wasp? What would the first sign of a gall wasp be?

A good question - one I thought of after posting. Well, wasps that use fruits as the developing area for the young use very fine egg tubes called ovipositors to 'inject' the larvae, whereas the weevil in question bores into it using the rostrum which I take to be bigger in diameter. As the hole and loss of contents is significant enough to make a notable difference to the weight of the nut, I thought something larger than a tiny wasp had to be involved. I also saw Lori's response which got me thinking.

As I said, it's a good question

[rangersarah2]

Thanks Jason. Would the first sign of the knopper gall wasp be the change in the acorn? How does the wasp that creates an oak apple make it's 'apple', and how does the one that creates a robin's pincushion make that one?

[rangersarah2]

Also (you asked for this), why and how does the acorn get deformed?

[thunder]

Originally Posted by rangersarah2

Thanks Jason. Would the first sign of the knopper gall wasp be the change in the acorn? How does the wasp that creates an oak apple make it's 'apple', and how does the one that creates a robin's pincushion make that one?

It isn't the insect that lays the egg that 'makes' the galls, but the effect of the egg (possibly) and the developing larvae. I don't think anyone is sure quite how this happens, and why gall shapes are so varied, but presumably the larvae excrete a chemical that provides them with this protection.

henrya

[Vincent86]

Agree with the people above me, it's the doing of an Acorn Weevil.