How To: Check For a Maggot in Your Apple
You’ve probably heard this old chestnut: “What’s worse than finding a maggot in your half-eaten apple? Finding half a maggot in your half-eaten apple…”
Here’s a quick guide to avoiding that rather unpleasant eventuality.
Know Your Enemy
Apple maggots, or apple worms, are the larvae of the codling moth1Presumably ‘codling’ is a derivation of ‘codlin’, an old name for a group of apples suitable for cooking in sub-boiling-point water – a process known as coddling, often now only applied to eggs – that’s preserved to this day in the names of heritage varieties like ‘Keswick Codlin‘. (Cydia pomonella). These insect pests emerge from hibernation and fly2Which is why grease bands offer no protection against them whatsoever. Pheromone traps are often recommended but are really more of an indicator than an eradicator; they catch some of the male moths, which then lets you know they’re active, at which point you can spray your trees with insecticide if you’re not Organically inclined. up into the tree in spring, when the blossom is in full bloom, and then lay their eggs on the leaves and sometimes on new fruitlets as well.
When the eggs hatch out, the emerging larvae tunnel down into the fruitlet, making themselves at home – eating and frassing all over the place – until they reach a suitably full-grown size. They then drop from the apples (if the apples haven’t dropped to the ground already due to the damage done by the maggots) and pupate in the soil, grass or mulch beneath the tree.
A second generation of moths then emerges in July and August. This second generation is the one that damages the maturing fruit, repeating the earlier lifecycle and then over-wintering in the soil or leaf litter, ready to emerge as breeding adults again next spring.
What to Look For
So how can you tell if there’s a nasty little maggot hiding in the depths of that pristine-looking apple before you bite into it? With careful examination of the fruit for the classic warning signs of maggot infestation, that’s how.
Sometimes it’s rather obvious that something has been eating your apples, due to the gaping wounds and/or brown rot that’s already developing around them. Often though, this sort of damage is due to pigeons or squirrels pecking and gnawing at the fruit, with wasps – or slugs, if the fruit drops to the ground – then moving in to enlarge existing holes.
Moth damage can be a bit more subtle and harder to spot. Here’s an example of a beautifully ripe and ready ‘Kidd’s Orange Red’ apple:
It looks perfect, doesn’t it? Ready for eating! But wait, what’s this? A tiny mark on the underside, near the ‘eye’ of the fruit:
On closer examination, you can see that it’s definitely a maggot tunnel, with the tell-tale signs of maggot frass (droppings) around the rim:
Hmmm. That doesn’t bode well. But it’s a small hole, so hopefully the damage will be limited. Only one way to know for sure, and that’s to cut the apple open, to see how bad it looks inside:
In this case, I was lucky. There’s only minimal damage there and I can easily get rid of the maggot tunnel3I knew it was definitely a maggot because I caught the horrible thing half in and half out when I picked the apple off the tree. Needless to say it was squished, pronto. and associated frass by quartering and coring the apple and then giving the quarters a good wash. It’s then perfectly good to eat4It was delicious, too; ‘Kidd’s Orange Red’ is by far my favourite dessert variety in the Plot #79 orchard..
One other thing to bear in mind: maggot tunnels aren’t always visible on first examination. Sometimes they don’t tunnel through the flesh of the apple if they can just get in through the ‘eye’ – the remains of the blossom, at the opposite end of the fruit to the stalk. Some apple varieties have particularly open, wide or deep eye basins, so it’s possible that a maggot could tunnel in through the ‘eye’ and not leave a clearly visible trail.
All of which explains why it’s a really good idea to closely examine an apple for the tiniest amount of damage before you chomp away, and ideally cut it in half to be absolutely sure. This is especially true when picking your own from an Organically managed tree that hasn’t been sprayed with pesticides.
Badly-damaged apples can still be (partially) eaten, of course. It’s important to cut away all damaged areas and wash the remaining pieces of fruit thoroughly to clean them up as much as possible. And it’s a good idea to cook with them, just to be doubly safe and sure. I’ve been making plenty of spiced apple compote from windfall apples this year and have filled up a tray in my freezer with packets of fruit that will keep my porridge interesting all winter long5Lashings of custard may also be involved at some point..
How about you? Do you have a sure-fire method for detecting codling moth damage? Do you know of any reliable, Organic codling moth controls (pheromone traps excepted, as discussed above)? Do let me know, via the comments section below.
Footnotes
- 1Presumably ‘codling’ is a derivation of ‘codlin’, an old name for a group of apples suitable for cooking in sub-boiling-point water – a process known as coddling, often now only applied to eggs – that’s preserved to this day in the names of heritage varieties like ‘Keswick Codlin‘. ↩︎
- 2Which is why grease bands offer no protection against them whatsoever. Pheromone traps are often recommended but are really more of an indicator than an eradicator; they catch some of the male moths, which then lets you know they’re active, at which point you can spray your trees with insecticide if you’re not Organically inclined. ↩︎
- 3I knew it was definitely a maggot because I caught the horrible thing half in and half out when I picked the apple off the tree. Needless to say it was squished, pronto. ↩︎
- 4
- 5Lashings of custard may also be involved at some point. ↩︎
Wij hebben in ons appelen fruitmadendaardoor vallen er veel naar beneden wat kan ik hiertegen doen? Ik weet vroeger bij mijn ouders dat na de winter de stamen 1 m behandeld werd ongebluste kalk na de winter is dat ook tegen die beesten of zijn er nu andere methodes? Dank bij voorbaat,aerts
Hi Aerts – If you have maggots in your apples then they’re probably Codling Moth. The bad news there is that there are no effective control methods apart from pesticide sprays. You can buy pheromone Codling Moth traps, but they’ll just trap a few males, which will indicate when the males are flying, to tell you when to spray. The non-chemical control would be to encourage more wildlife in amongst your trees – nesting boxes for small birds, perhaps. And to clear up as many fallen fruitlets as you can as quickly as you can, to try to prevent the maggots burrowing out and into the soil, where they’ll hibernate until next breeding season.
The quicklime was probably a defence against rabbits or deer? Or possibly Winter Moth. The females of the Winter Moth have no wings, and crawl up the tree trunk in early spring to lay their eggs in developing apple flower buds. The quicklime might have been sticky enough to catch them. These days we use grease bands or sticky paint. But neither of these will work against Codling Moth, because both males and females have wings.
So are you saying we have to spray? I’ve tried the attractive apples, picking up the apples, sticky tapes all over the tree to avoid spraying but no go! They just destroy our fruit and have been doing this for years:(
What about covering the ground underneath the trees with tarp so they can’t fly through?
Hi Melanie – I’m really sorry to hear that your control methods haven’t been successful. It sounds as though the population of moths has built up to the point where it’s no longer practical to control them, there are just too many to catch them all.
I’m not sure that spraying – even organically approved compounds – would necessarily be the answer either. Depending on where you’re based, and what scale you’re growing at, there might not be an effective chemical control that’s available. The products described in Organic Fruit Production and Viticulture by Stella Cubison might be worth looking into, but again, unless you’re growing at orchard scale, they might not be in any way cost-effective, or even available without a license. Michael Phillips lists a whole range of potential controls in The Apple Grower (p.171), so it might we worth taking a look at that.
In the meantime, this might sound a but simple, but have you tried encouraging more birds into the area where you grow your trees? A few nesting boxes suitable for small birds might help to develop a local population that could reduce moth numbers by eating the adults and larvae and probably help with aphid control too.
Very best of luck!
Thank you for the article. I enjoyed reading it. I said to myself: You must peal the skin of an apple to see the pin-start of a trail.
SS
Hi Shahid – Yes, always a good idea to double-check for maggot problems. It’s a bit of a shame to peel the whole apple though, as that’s where a lot of the fibre and phytonutrients are to be found. If you cut it in half that will usually reveal any maggot damage, and you can still eat the skin.
Would spreading diatomaceous earth around our single tree help?
Hi Corynne – I haven’t used DE myself but I did find this article that suggests it’s usually applied as a dust spray, rather than a ground mulch. It might have some effect if you used codling moth traps as an indicator to see when the adults are active and then dusted the tree, but the larvae tend to spend most of their lifecycle inside the fruit, so the dust probably wouldn’t reach them? Applying DE to the ground around the tree seems unlikely to have a full effect, because as soon as it rained the DE would be washed down into the soil and lose its potency? Again though, I’m not entirely sure as to the properties of DE so more research would be the best idea.
I have a golden delicious apple tree that appears to have the coding moth maggots as shown in your pictures above. What pesticide would you recommend if I can use organic pesticides?
Hi Robert – I’m afraid I have no experience of pesticides, organic or otherwise, so I wouldn’t like to recommend anything in particular, but Michael Phillips lists a whole range of potential controls in The Apple Grower (p.171) so that might be a good place to start.
Mr. Darren T. After your long explanation of Apple Maggots, it would have been nice to have ended with a reassuring note, if eaten and swallowed would we die or live?
Hi Mark – That’s a great question. Now, I’m no toxicologist, so please don’t take my word as medical advice, but I can’t imagine that accidentally eating a codling moth maggot (or even half a codling moth maggot…) would do you much harm. If anything it would be a bit of that extra protein that the health podcasts are always telling us we need. And in my experience, if you bite into a frass-filled apple then the texture alone would have you spitting it back out in half a second flat, and then your biggest worry would be whether you have a water bottle to hand so you can wash your mouth out. Ick.