Bucket for Budget Bucket Moth Trap

Using a off the shelf bucket with a lid to make a moth trap is a very cost effective place to start. Here is an approach to using such a  bucket.



We have selected an all black bucket with a good fitting lid. They are used in hydroponics and food industries. Ours is a 20 litre capacity which is nearly as wide (32cm) as it is high (34cm); we looked for one with the largest lid area.

Entrance funnel

A large (in our case 21.5cm) household funnel that we cut down by 10cm to give a 4 or 5cm gap to the top of the drainage funnel. The diameter of the bottom of the funnel can be as little as 3cm allowing large moths in while making it difficult to get back out. It is worth considering painting the bottom part of the funnel matt black to avoid it being at all lit up and attracting moths to a possible exit from the trap.

Drainage funnel

Optionally, an 80mm diameter powder funnel where the spout fits neatly into the drainage connector, can be used. The spout needs to be slightly smaller than the tank connector inside diameter. The funnel should be as obtuse as possible to avoid 'catching' the moths as they fall through the main funnel and so stopping them getting into the main body of the trap and away from the main funnel 'exit route'.

Netting The funnel can trap moths and so using a piece of curtain netting, about 10cm square, jammed into the funnel spout allows water to flow, but protects the moths

Drain connector

A straight 21.5mm overflow tank connector nicely supports a funnel to catch any water ingress down the entrance funnel.

The connector needs to be cut down to avoid protruding out of the bottom of the bucket's base.

Egg boxes Collect and reuse your own egg boxes or for neater stacking larger trays can be obtained and cut down with a smooth, sharp carving knife.


Cut hole in lid to fit entrance funnel

The entrance funnel should have a good lip so that there is no risk of the funnel falling through the circular hole in the lid. The diameter of the hole in the lid needs to be measured carefully to be very slightly greater than the outer size at the top of the sloping sides of the funnel.

For the 215mm outside rim diameter funnel we use  the hole required is 202mm.

We have a circle compass cutter to make the hole. The lid is just about thin enough (1.2mm) to cut with a Stanley knife, but difficult to control so using good kitchen scissors or snips may be best. A drawing compass or string around a drawing pin held at the centre of the lid can provide the line to cut around.

Cut hole and fit the drain connector

For the tank pipe connector we use a 28mm hole cutting drill to create a neat hole in the centre of the base of the bucket.

The nut from the drain connector can be tightened to securely hold the connector in place. If the tank connector is made from a solvent weld plastic then use a hard plastic adhesive to hold the nut in place permanently.

Six or eight , 6mm or 8mm, drainage holes should be drilled around the perimeter of the base of the bucket to allow any rain water that escapes the drainage funnel to drain away.

Fit netting into funnel spout Fold the netting up and jam it into the spout of the drainage funnel such that it doesn't come out easily.
Fit the drainage funnel When using the trap, simply place the drainage funnel into the connector. The funnel may need cutting down so that it is shorter than the pipe connector.
Fit the entrance funnel into the lid and attach your light assembly

After filling the bucket with egg boxes in a way that keeps clear of the funnels, the lid can be replaced, the entrance funnel should slot into the lid.

Using the trap

Affixing a  small note to the trap explaining what it is, that the moths aren't harmed and some contact details may be worthwhile.

The trap is also quite light in weight which is great, but does mean that it can be affected by gusts of wind potentially blowing it over. To mitigate against this either put a rock, found near to the trap site preferably, inside the trap or have a 1.5m length of guy rope over the top of the bucket and a couple of tent pegs with which to attach to the ground.


To complete the trap follow one of the two options for the light:

See how to make a compact fluorescent light for this trap

See how to make an LED light for this trap

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