Cabbages, broccoli, cauliflower, and all the wonderful other brassicas are targets for Cabbage White Butterflies in warmer weather.
In past years, we gave up on growing these crops as the caterpillars which hatch from eggs laid by these butterflies chomped them so badly we got little return for any planted to mature in warmer weather without a lot of effort.
Spring arrived and the butterflies appeared here in Auckland.
I was intrigued to see posts about using decoy white butterflies as deterrents.
So, I decided to run my own experiment as to how imitation female white butterflies would work for our garden.
Seemed simple enough:
The female cabbage white butterflies are territorial. If they see another female then they go off elsewhere. [Male butterflies have different markings to female].
Put fake female white butterflies around susceptible crops
and the real butterflies go elsewhere.
So, first make some imitations of the female butterflies. Some nice people have put together a template with lots of correct size images:
which looks like this.
I printed it then followed the instructions in http://goodseedco.net/blog/posts/cabbage-butterfly-decoy:
- Cut out the individual butterfly images. [which took me back to kindy ‘cut and paste’]
- Collect string, scissors, clear packing tape.
- Use wide, clear packing tape and lay it flat, sticky side up. Lay string on tape then place a white butterfly image on top. [I lay out a number along the tape]
- then cover the lot [2 sets of hands would help!] to stick more packing tape over the top to hold it all together [sticky side down onto the paper image]
- Hang above susceptible crops to flutter in the breezes, just like real butterflies do. Movement is apparently important too.
So, the important parts:
- Image must be of FEMALE white butterflies with their markings.
- Decoy image must flutter in the breezes.
I love experiments! I wonder how effective these will be?
RESULTS and UPDATE:
How amazing – the first year we have had minimal caterpillar damage to broccoli and kale! There are white butterflies around, as in past years. But far less damage from caterpillars!
So we will in future hang these lovely little decoys about the broccoli etc and look forward to better crops than previously – what a wonderful simple solution to a pest problem!
May your brassicas be ‘munch-free’ so easily too