DIY moth trapping
Mallee Looper moths (Arhodia spp.) attracted to a moth sheet. Photo: Mark Hura.
We are expecting the Mallee Looper (Arhodia) moths to begin emerging from their underground pupae around the end of November. Could be earlier, could be later. We think the moths might emerge a week or so after a Spring rainfall event.
The best conditions for trapping moths is around the new moon, when it is nice and dark. A calm, humid and warm night helps also. Under these conditions, researchers in South Australia trapped over 700 Arhodia moths in a single night, in a single trap! (1)
But how do you trap moths you may ask. Read on for moth sheets and moth traps …
A moth sheet set up on Raakajilm.
What is a moth sheet?
It’s deceptively simple. Hang a white sheet from a rope and place a moth-attracting light nearby. Moths are lured to the light and rest on the sheet making photography pretty easy. But it’s a night-time activity. The really keen folk might check their moth sheet all through the night… Did I mention I’m a morning person? If the moths haven’t arrived by 10pm, I’m out.
I have had some excellent evenings with a moth sheet though. Like when Roger Standen and I found a Hawk Moth that was a new species for Victoria and a significant southern range expansion (Coenotes eremophilae).
For the light and power source: I use a 240V replacement light for bug zappers 50W Gecko brand (about $30). It is fitted into an Arlec 60W handheld work light housing with a 5m lead ($15). I plug it into a power point with an extension lead or a battery with inverter like the Powertech 155W power station ($220).
Desert Hawk moth (Coenotes eremophilae). The first record for Victoria was on Raakajilm and a significant range expansion.
What is a moth trap?
I don’t like staying up late at night so I was very excited to discover the set-and-forget moth trap.
There are many designs but the one I have chosen is a bucket with a funnel in the lid. The light is suspended above the funnel and is surrounded by four transparent vanes. The moth flies towards the light, hits the vanes and is directed down the funnel. Moths accumulate in the bucket overnight and I check them in the morning. No sleep lost!
You can use a kill fluid to make sure your moths don’t fly away. So far I haven’t needed it. I line the bucket with a mesh bag and I sometimes need to pop the bag of moths in the fridge. The cold makes them less active so they are happier to pose for photographs. My family loves opening the fridge to find it full of moths.
That said, I’ve only been using this moth trap in the cooler months when there are fewer moths about. I may run into trouble on warmer nights when there are gazillions of very active moths. We will see.
This is my DIY moth funnel trap:
A home-made moth trap, coming in around $100 including the power source.
Make your own moth funnel trap!
To make your own funnel moth trap get yourself:
20L bucket ($15)
Giant big mouth funnel ($12).
Insect netting ($8 for 120x210cm) - this is enough for two traps
4mm clear twin wall polycarbonate sheet ($16 for a1200x600mm handisheet from Bunnings). You can cut vanes for two traps from one sheet.
A 5W USB UV tubelight ($22)
A 20,000mAh power bank ($40)
Total spend = $113
To “build” it:
Attach two bits of cord to the bucket so it can hang from a tree. Or you can leave it on the ground.
Cut the netting into a piece 130 cm x 60 cm. The netting is draped inside the bucket to give the moths somewhere to land.
Cut the long bit off the funnel, leaving about 1cm. The funnel will fit neatly into the bucket.
Cut the polycarbonate sheet into two pieces 29 cm x 42 cm (see the pattern here). We used a circular saw (with full face mask protection for plastic shards).
Cut a slit in each piece of polycarbonate (again, check the pattern). For piece A, cut a slot 22 cm long from the square end. For piece B, cu a 19.5cm slot from the pointed end. The two pieces slot together to make four vanes that sit inside the funnel.
That’s all the building!
Parts of the DIY moth trap: 20L bucket, cut-off funnel, transparent vanes, 5W LED UV light, 20,000 mAh power bank.
How to use the moth trap
Find a spot in the bush or your garden to hang the bucket from a tree branch, or you can leave it on the ground.
There are two options to drape the netting inside the bucket:
Fold the netting in half and drape it inside the bucket. Make sure the long edges overlap by about 5cm so the moths don’t sneak out the sides. Secure the netting at the top of the bucket with a really big elastic band. This is the easiest if you are going to photograph the moths straight away. You can easily remove the elastic band and then lift the netting out of the bucket and spread it out flat to see your moths.
But … if you need to subdue your moths in the fridge you’ll need to “sew” up the sides of the netting using a 45 cm piece of light wire. This makes a bag that goes inside the bucket. In the morning you can remove the bag, place it in the fridge for an hour or two, then unthread the wire and spread the bag out into a flat piece so you can see and photograph the moths
Once you have arranged the netting inside the bucket, place the funnel in and then sit the vanes on top.
Plug the UV tube light into the powerbank and hang your light inside the vanes, just above the funnel mouth.
That’s it! Turn it on in the evening. Go to bed and return in the morning to reveal your moth bounty!
Caution
〰️
Caution 〰️
The UV lights will attract moths. Sometimes a lot of moths. Occasionally they might choose to explore your ear holes. This is not pleasant. Please wear ear plugs or a beanie so the moths can’t get in.
This project of the Regional Drought Resilience Planning program is jointly funded through the Australian Government’s Future Drought Fund, the Victoria Government and the Natural Resources Conservation Trust.