Will 6 month old compost attract winged insects?

Hi Permies! This is my first post and I'm happy to find this new home.

I've been composting my kitchen and garden waste since december 2014. I used 'be green general compost maker' (natural enzymes and micro organisms) to start and accelerate the process. I'm using a 'Green Johanna' bin.

I initially had the bin located under my kitchen window in the front garden which made it quick and easy to empty the kitchen compost pail into it. Around March of this year, the bin started attracting smalled winged insects, which lived in the bin and started flying into the house and congregating on the fruit bowl. As the weather got warmer we had more winged insects in the house so I decided to relocate the compost bin to the bin shed of the estate I live on. I had to empty the bin to do this, and noticed that the material at the bottom of the bin had decayed well into squelchy brown matter, with only a bit of orange peel and egg shell as evidence of its previous form. The bin still attracts plenty of winged insects but they do not bother anyone near the bins.

I have recently been donated a planter on legs by my neighbours. I've been sowing seeds through spring and have some healthy carrots, parnsips, kale, lettuce and herbs to plant in the planter. I want to use some of the compost from my bin in this planter, its volume is 320 litres. I plan to used about 90 litres of compost from my bin and I have bought 200 litres of organic compost from a garden centre to mix with it. I've located the planter in my front garden below my kitchen window, in the same spot where the compost bin used to be.

So the big question. Will the 6 month old compost from the bottom of my compost bin attract flocks of winged insects? Am I likely to have the same problem as before with winged insects flying into the house as using the fruit bowl as their hotel? I am thinking of using my bin compost as the bottom layer in the planter, and then covering it with the organic compost bought from the garden centre.

I would be grateful for opinions! Thanks!

How does that compost smell?

I'm not sure as it's still at the bottom of the compost bin.

When I moved it three months ago, it smelled really strong, like fresh poop.

That could be part of the reason that you're attracting flies. Sounds like your compost went anaerobic. Using anaerobic compost is usually frowned upon in the gardening community, however if you're dead set on using it in your planter box, just make sure it's covered up with a couple inches of clean cover material such as paper, sawdust, or extra soil. That should suffice to keep the flies off.

Insects are going after the compost because it offers something they are looking for:
-food
-moisture
-warmth
-a breeding environment

FOOD
Regardless of the stage of decomposition, most of the material in that bin will offer a food source for some kind of insect. It may not be the orange peel the bugs eat, but the bacteria and decomposed material which offers a delicious meal. Insects have a limited digestive system. Organic matter that has broken down makes it possible for some insects to consume what they could not otherwise ingest.

MOISTURE
Bugs need water same as everything else but they don't much. Standing water such as a birdbath does not offer a stable surface to land on whereas moist grass clippings provide purchase from which the bugs can slurp up the water they need. There is no getting away from moisture if you wish to compost.

WARMTH
The warmth is important when the seasons are changing. Bugs have a different way of seeing the world and can detect infrared (heat) as well as UV sources. Being a cold blooded creature, they'll be drawn to it. At this time of the year it's not a factor.

A BREEDING ENVIRONMENT
Bugs eat, mate, breed. That's what they do. A warm, moist, food rich compost bin is an ideal environment. As long as the bugs are hanging around eating and drinking, they'll find a hugger and set to work keeping their genes pool alive. For momma's precious little snowflakes, it's hard to beat a compost heap for egg laying. From the perspective of the compost maker, the bugs are good workers helping to decompose the material.

With all this in mind, the task is to make the compost less attractive to the bugs. Bugs have 2 primary methods of detecting your compost: light (including IR) and chemical. Those antennae are able to detect the odors emanating from the compost. Evaporating moisture will carry chemical signals through the air. Looking at your compost bin I see it is essentially an inverted trash can with solid sides. There is some ventilation on the bottom, but not enough to allow the material to dry out. This is by design as these small containers need to retain the moisture in order for the contents to decompose. If that same volume was a heap o the ground it would be able dry out completely, weather permitting.

That small volume won't heat up to such an extent as would a cubic yard heap. It's just not big enough for the thickness and depth of material to serve as insulation. We can eliminate visual cues as a reason for drawing the bugs. This leaves odor as the attraction.

The compost bin does not have to be a reeking cesspool. Light odors will be enough to draw in the bugs. Looking at the bin there are vents on the bottom and what appear to be vents on the top. What you have, in effect, is a chimney. You toss in new material, stir it up. This keeps it loose and allows air to flow. There will be some warmth which will create some airflow. In that air is moisture and chemical signals. It's a big neon sign for bugs. Those plastic bins retain much more moisture than an open heap. Those open heaps dry out on the outside. Once again, it's the thickness and depth of dry material that absorb that moisture before it passes out of the heap. The moisture will still move through eventually, but in the meantime it is a barrier preventing access to the moist material which the bugs need to eat, drink, and propagate.

Once you use the material in your garden or containers, you'll have the same effect: a dry surface acting as a barrier. The core of the planter will still be moist but the bugs won't be able to get to it in such numbers that they become a problem. I hope that answers your question.

There still exists the problem of the bugs in your bin. I suggest leaving the cover off to let it dry out some. You could also add some dry material to reduce the moisture level inside the bin.

Thanks very much for the views.

I have done as suggested and covered my home made compost with store bought compost.

All the best

Hagop