Whatever happened to the mealworms?

Adult and juvenile

Adult and juvenile Tenebrio molitor… and a cauliflower stalk

Well, that was a question that I had been asking myself too. You may remember that I was having a go at raising mealworms as a source of protein-rich food for my hens (details here). I’ve been very quiet on the subject recently because I thought that it hadn’t been successful and I was looking at other options, However, I am pleased to report that the lack of success was only because I hadn’t been patient enough. I decided to tip the contents of my three mealworm tubs into a bucket last week with a view to feeding the contents to the chickens and giving up. However, disturbing them like this revealed much more life than I had thought remained.

Never having had a go at this sort of thing before, I knew little about the ecology of Tenebrio molitor, the species in question, so I wasn’t sure what to expect. I think I may have been wildly optimistic about the speed of the lifecycle… a salutary point about doing your research first! I’ve now done more reading:

The life cycle of Tenebrio molitor is of variable length, from 280 to 630 days. Larvae hatch after 10-12 days (at 18-20°C) and become mature after a variable number of stages (8 to 20), typically after 3-4 months (at ambient temperature) but the larva stage can last up to 18 months (Feedipedia)

All the life stages seem to be present now

All the life stages seem to be present now

So, the fact that I was not seeing large larvae as soon as I expected after raising the adults was certainly because it was too soon. My newly disturbed bucket, in fact, contains lots of mealwormlings, as well as live and dead adults, large larvae and a few pupae. They are currently feeding on rolled oats and gaining moisture from pieces of potato and cauliflower.

In addition, I discover that

Commercial mealworm producers sometimes include a juvenile hormone into the feed to prevent the larvae from molting into adults, resulting in “giant” mealworms that can achieve a length of 2 cm or greater and weigh more than 300 mg (Feedipedia)

A range of sizes of larvae

A range of sizes of larvae

Meaning that I may not be able to produce the big chunky mealworms that are available to buy from pet stores.  I don’t really mind this, because the hens are not fussy about the size of their food! And I suspect that the size issue is important for producers of dried mealworms, because they are bound to shrink with the loss of water as they are dehydrated.

During my recent research I discovered that the species is also known as ‘Darkling Beetles’, which sounds rather romantic to me. Plus, I was amused to read on one site:

Tenebrio molitor larvae are easy to culture (they are often raised on oats, and females lay up to 500 eggs), high in protein, and readily available commercially, so are a good food source for pet owners

But personally, I don’t fancy snacking on them myself!

Anyway, I will continue to care for my colony and see if I can viably produce enough to replace some of the chickens’ feed.


If you’re squeamish, don’t read this and certainly don’t watch the video…

When we first got chickens five years ago, the aim was to convert slugs and weeds into eggs. Of course, for a chicken to make an egg it needs calcium, protein, water and various minerals and the easiest way to provide all these things is to feed your hens commercial layer pellets. Because our hens free-range and have access to a variety of habitats, they forage quite a bit of their own food, but they still need some supplementary feeding. In a small garden there is a limit to the amount of chicken feed you can grow, so this is a compromise that we have had to accept. We give them any slugs and snails we come across when we are working in parts of the garden they do not have access to and I give them weeds that I have removed – docks from the fruit cage are a particular favourite at the moment. But, even so, they get through more organic layer pellets than I would like. Indeed, since they have done such a good job of reducing the mollusc population, they are getting less food from this source.

The new livestock arrives

The new livestock arrives

A couple of winters back we had very cold weather (for here) and  boosted the hen’s diet with mealworms, which you can buy live or dried and which are sold as wild bird food. The hens LOVE these, but they are rather expensive. I, therefore, decided that the time had come to try to produce my own. Mealworms are the larvae of flour beetles and can be raised on bran or oats (no need for rotting corpses as you need for maggots) so they seem like a good source of protein to produce for use as chicken feed when space is limited. I’m not particularly bothered by insect larvae, so over the weekend I bit the bullet and ordered a mealworm starter pack, so that I can grow my own!

What you receive is three tubs of live mealworms, a bag of mixed bran and calcium and a set of instructions. To be honest, I think the instructions are little lacking, but hey that’s why we have the internet! So, I sprinkled a good covering of bran into a plastic tub and added the larvae, before giving them some yummy chard leaves, which they ignored:

Fresh greens?

Fresh greens?

A bit of reading around revealed that they like something a bit more chunky to get their mandibles into, so later I added some satsuma pieces. The fresh food provides them with their only source of water, so it’s important to make sure they have it. Apparently they will pupate in t”a few weeks” at which point I will need to transfer them into another container without bran before moving the adults into a third container when they’ve emerged. At this point they will mate, lay eggs and die and I will them wait for more mealworms to hatch. In theory I will get increasing numbers and thus food for hens. Our local mill has an excess or bran, so that’s not a problem as regards feeding and I can give then vegetable peelings/waste as their water source. So, I’m hoping that this is a pretty sustainable, environmentally sound method of producing some chicken feed. It won’t replace the layer pellets, but it will reduce the need for them a bit.

And now, just to make you squirm, a slightly wobbly video of them when I first put them in the bran:

Just chicken-feed

It has recently come to my attention that, in the UK, it is illegal to feed kitchen scraps to chickens. According to the latest edition of The Organic Way*:

the law against feeding kitchen scraps to poultry of any sort has been in position since the foot and mouth outbreak in 2001. It was produced by the then Department for Environment, Food and Rural Affairs**, to reduce the risk of spreading disease. The same rules apply even if the household is vegetarian

Chickens acting within the law by eating worms and insects - no (illegal) kitchen scraps in sight!

Chickens acting within the law by eating worms and insects – no (illegal) kitchen scraps in sight!

So, now you know – if you live in the UK and you give your vegetable peelings or toast crumbs to your hens, you are breaking the law. If, however, you make a piece of toast specially for your hens, I guess you are behaving legally. It’s a fine line… if I take leaves off my brassicas in the garden and feed them directly to my hens then it’s ok; but if I’m preparing dinner and discard a few leaves of kale I picked 20 minutes ago because they are a bit tatty then give these to the hens, I’m a criminal.

I have visions of the ‘hen police’ coming round to check that any kitchen scraps go to the worms or the compost bin or the dogs and are not surreptitiously diverted to the chickens.

It appears that the law, in fact, is the UK’s interpretation of the EU animal by-product legislation. Interestingly, other European countries have interpreted this law differently, so in Belgium there is a project that actually promotes keeping hens in order to reduce waste. Sigh.

Ah well, it looks like I’ve found another outlet for my civil disobedience!


* The membership magazine of Garden Organic

** Always known, in our house, as the Department for the Eradication of Farming and Rural Affairs

Soil – getting to the root of things

Unless you are practicing an unconventional system of cultivation like hydroponics (see this great blog if you are interested in doing so) then soil is the foundation of everything you grow.

Gardeners tend to value their soil – they see what they are taking out in terms of crops and try to put something back – often by adding compost, soil improvers or fertilizers. My favourite addition to the soil is compost because it doesn’t cost me anything – I am converting what others would regard as waste (from the kitchen, garden or chickens) into a useful resource. I don’t tend to use commercial fertilizers or feeds, relying on compost, woody material from the willow hedge and other prunings, and worm wee. That’s not to say that I won’t use commercial fertilizers, I’m just too mean to buy them! I received a free gift of some organic liquid tomato feed earlier in the year and so I have recently been using this on potted crops – although it does make the greenhouse smell like someone has been storing fish in there for a week!

Unlike gardeners, many large-scale agricultural enterprises don’t use their ‘waste’ outputs as a resource, choosing instead to treat organic matter as rubbish and buy in fertility in the form of fertilisers derived from the petrochemical industry. In a recent post, Yambean highlighted the shocking waste when Spanish farmers dumped cucumbers in protest at being paid so little for them by the supermarkets. I asked her about this and commented that they would, surely, have been better composting them and returning them to the soil, but she tells me that composting is unheard of in that part of southern Spain and the soil is, as a result, completely impoverished. It’s shocking to me.

Soil is a complex system consisting of a mineral component, organic matter in various states of decomposition (from freshly fallen leaves and recently deceased animals to humus and root exudates) and living organisms (bacteria, fungi, worms, insects, other invertebrates, plant roots etc). It is common sense that we need to nurture such systems if we wish to make use of them. Unless we replenish the soil, it will not continue to be productive. This was the basis of the organic movement in the UK, you know? Ever wondered why the Soil Association (one of the regulators of organic produce here) is called the Soil Association? Well, it was founded in 1946, partly because of concerns about “the loss of soil through erosion and depletion”. In 1967, the association stated that “The use of, or abstinence from, any particular practice should be judged by its effect on the well-being of the micro-organic life of the soil, on which the health of the consumer ultimately depends.” So, you can see that their name really does reflect an acknowledgement of the key importance of the soil.

In large-scale systems, particularly where it is common to have periods when the soil has no vegetation cover, erosion is common. As the Soil Association noted in 1946, soil is not simply lost as a result of nutrients being extracted because we grow crops in it, erosion is also a problem. If you live beside the sea (as I do) you cannot help but notice the brown water around river mouths after heavy rain… this is the soil that was previously supporting plants. It does get replenished naturally – rocks weather and add to the mineral component, organisms die, excrete and shed parts of their bodies and add to the organic matter – but bare land is subject to high levels of erosion that can take a significant time to be replaced. Thus we lose substrate, nutrients and water-holding capacity because we chose to leave soil bare – a simple ‘green manure’ such as clover could reduce the erosion and enhance fertility (clover fixes nitrogen).

If we do not care for our soil is it any wonder that there is an increasing need to add to it from external sources and rely on non-renewable resources? Many people, when thinking of organic growing, focus on the absence of pesticides, herbicides and artificial fertiliser, but I’d like to suggest that one of the most important reasons to support organic production is because its practitioners care for the soil and are, thus, ensuring that it is available for future generations to use too. In my garden, I would like to think that I will leave the soil in a better condition than when I found it… not just preservation, but enhancement.

Free range chickens and caged vegetables

I read an interesting post the other day about chickens as protein harvesters and then my attention was drawn to another post about reducing the amount of brought-in feed for chickens, and yet another about creating a chicken foraging system. All of which set me thinking about my own hens and their inputs and outputs.

Aliss hard at work: cultivating and eating pests

Now, I’m quite clear about the outputs: eggs for us to eat and barter, fertiliser and compost activator, entertainment, pest control (slugs and snails), weed control, cultivation (particularly useful for incorporating new material into the “rubbish” beds) and consumers of left-overs (although few and far-between in reality). There are also a few minor things like feathers for craft projects. So, we get a great deal out of them Even if I just consider the saving on the cost of nematodes to control the slug population and the number of eggs now available to us as a protein source, I feel that they make a great contribution to our economy.

However, when I consider the inputs, I realise that we are buying quite a lot in for them – layer mash or pellets and corn are the main items, but we also use Poultry spice and Vermex to make sure they are healthy and worm free. When we first started keeping chickens they remained in a run and all the food, apart from the grass that they quickly ate, was bought in. As we have come to understand the value of hens in the garden, they are allowed free access to most of it for most of the time. This means that they consume less bought food and instead eat wild plants, slugs, snails, grubs and worms. As chickens that have been brought up outdoors, we find that they are eager to eat worms and molluscs (although they are not keen on the caterpillars of the white butterflies). We do, however find that they don’t like to be confined and they (as the descendents of jungle fowl) particularly like spending time foraging under the willow hedge and associated shrubs.

We started off with a chicken ‘coop’ that claimed to be big enough for four hens:

Our coop when we were building it.

Don’t be fooled by such claims! The house part has a perch that will accommodate three average-sized hens; the run itself barely has room for four of them to move around once there is a drinker and a feeder in there (even if they are suspended). The result is cramped hens and food and water either knocked flying or full of muck. We soon realised that this was no way to go on and started putting them in the fruit cage, with a net tunnel leading back to the coop so they could lay in the appropriate place. Of course, once the fruits started appearing we found ourselves in competition with the hens. I like raspberries way too much to want to feed them to chickens, so they were banished from the fruit cage. By this stage, they were all used to coming when called and happy to go in and out of an expanded run attached to the original coop, so since the garden was already terrier-proof we hoped it might also be chicken-proof and decided to let them roam free.

Gytha – the Houdini of chickens

I have some news: a terrier-proof garden is not, in fact, chicken-proof. The late lamented Gytha was particularly good at getting out. We used to get phone calls from our neighbours opposite to tell us she was sitting on our front doorstep! Once all escape routes had been blocked in that direction, she took to escaping into the field behind to run around with the sheep. At my age, you really don’t want to have to call round to the neighbouring farm to ask if you can please have your chicken back! Finally we worked out how she was getting out and blocked that egress. After that the only issue was protecting the vegetables. Unsurprisingly we have found that whilst chickens like to roam free, vegetables are quite happy to be caged! So, we have chicken exclosures rather than enclosures. This seems to work out well for the welfare of both hens and veggies.

Our next task is to focus on producing some crops specifically for chickens. I have yet to research what might keep them worm-free (any suggestions welcome, but I’m guessing at least garlic) and fully supplied with vitamins and minerals (comfrey perhaps?). But I have read somewhere that they like chokeberry (Aronia), so I have one of those on order from the Agroforestry Research Trust and I’m hoping that Siberian peashrub (Caragana arborescens) might be a good source of food for them (some seeds are on their way from Lithuania as I write) as well as flint corn (as grown by Carol Deppe). In addition, I’m broadcasting wheat seed in the fruit cage in the hope that some will germinate and provide heads to be eaten directly by the chickens once the soft fruit season is over. I plan to turn the small overgrown area at the front of the house into a source of chicken feed since i don’t really like gardening out there as I’m not a sociable gardener! Finally, I hope to up my production of worms in the wormery… another great food for chickens. Although I don’t envision being self-sufficient in chicken feed, I would like to reduce external inputs without compromising our human food production. I’m hoping too, that the result will be healthy and happy hens.

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