What Time Of Year Do Cabbage White Butterflies Lay Eggs?
It’s August 2022, and today I discovered that the radish seeds I had set a little while back have been devoured overnight by the cabbage worms commonly known as the cabbage white caterpillar.
There are in fact so many of these green caterpillars scoffing my radish leaves that it’s unlikely I’ll have any more of those lovely peppery veggies. Sob.
So, I wanted to share with you all that I know about this pesky pest so that you and I are better clued up for next year.
What Is The Cabbage White Butterfly?
A pest if you happen to like growing your own brassica crops, but when fluttering around, they’re a lovely white butterfly which looks like butter wouldn’t melt. There has been a large cabbage white butterfly visiting my roof terrace frequently and it was clearly in search of one of my veggie plants to use as a host plant. I did not realize that they considered radish to be tasty fodder or I would have been more careful!
The cabbage white butterfly (aka pieris brassicae for the large white and pieris rapae for the small white) only has a lifespan of three weeks – if it has eaten well, but less if it has had minimal nutrition. If you see a large white butterfly with two spots, its the female, and the males are those sporting one spot on each wing.
Once a cabbage white has found a plant of their liking they lay their eggs. They do not cluster them together, but instead just go crazy with the randomness, so you have to really scour the leaves to remove them – more on that below!
What Do The Cabbage White Eggs Look Like?
When I first spotted the eggs on my newly growing brussels sprouts, I wasn’t sure if what I was seeing really was the cabbage butterfly eggs. They were tiny, small white eggs hiding on the underside of each leaf.
The eggs on the radishes are bigger – small dark green pellet sized eggs, which are in fact the larvae. I’ll add photos so you can see how grim they are.
How To Remove Small Cabbage White Eggs?
The small white eggs I easily picked off and disposed of, but clearly I should have taken more care with the radish.
You can also brush them off with a small brush – a paintbrush perhaps? – if you’re squeamish and don’t fancy touching them with your hands.
If you’re not successful in clearing them, you’ll end up with the cabbage caterpillar scoffing any brassica plants that you might be hoping to grow!
I wasn’t successful in removing mine, and judging by the color of the green caterpillars scoffing my radishes, I’ll be experiencing many small white butterflies (Pieris rapae) appearing in a week or two.
How Long Do Cabbage White Caterpillars Live For?
Once your larvae have become bigger caterpillars and eaten their way through your susceptible plants, they will settle down and create their cocoon, also known as the chrysalis or pupa. They stay in this stage for about a week before emerging as a white butterfly ready to cause more havoc on any remaining outer leaves of your plants.
What Time Of Year Do Cabbage White Butterflies Lay Eggs?
Safe to say from my recent experience that the egg laying stage of cabbage white butterflies happens in July and August where I live in the Northern hemisphere, but they are still active in late spring and fall, if the temperature suits them.
What Plants Do The Cabbage White Butterfly Destroy?
Destroy may be a harsh word to describe a butterfly, but destroy is what they have done to my radishes! Here’s a short list of plants that they find quite tasty:
- Broccoli
- Brussels Sprouts
- Cabbage
- Cauliflower
- Kale
- Kohlrabi
- Radishes – I can attest to the utter destruction of radishes by cabbage white!
- Turnips – this is on authority from my dad who lost his to cabbage whites!
Needless to say that next year when I get to planting any brassica plant seeds I’ll be making sure to use some preventative measures to keep the pesky adult butterfly away!
Protecting Plants From Cabbage White Butterflies
Finally, let’s look at how you can protect your plants and keep the tasty harvest for yourself and not the white butterfly!
I know that many consider butterflies to be beneficial insects like bees (my other half is one) but when you’re growing veggies in such small amounts like I am – a small roof terrace does limit the options on what I can grow – then they are more of a pest and we need to be on it to ensure we do see some of the crop.
And in all honesty, I didn’t even realize that the cabbage white was team radish – evidenced in there being four caterpillars scoffing the one leaf below – so now I know for next year, and will be sure to put in place some preventative measures.
Individual Pots
Fine netting is your best bet for keeping both butterflies and moths away from plants in individual pots, and it should have a maximum mesh diameter of 1/4″ / 5mm to make sure they cannot penetrate it. Make sure that you have it nice and taut, and nicely pinned down too so they can’t get underneath.
Veggie Patch
If you have more than one pot or a veggie patch with susceptible plants then you can make a simple frame with mesh netting. This should again be fine to stop the butterflies from getting through, but provides a little more space for the plants rather than covering them in mesh.
Egg Shells
This is a method I recall my dad trying when I was growing up – there were always plastic containers full of crushed egg shells by the kitchen sink – but I don’t think it was ever successful as he hasn’t grown any brassica plants in a long time. In fact this year – inspired by my brussels sprouts adventure perhaps? – he has set some cabbage seeds, but is worried about them being scoffed by the cabbage white.
I’ll keep you posted on whether he tries the egg shell method, but as the eggs are laid on the leaves of brassicas it won’t stop any that hatch on the plant. It may however prove useful in keeping them away from other plants!
I have loved sharing my cabbage caterpillar antics with you. I’ll let you know what happens next as they evolve onwards and good luck with protecting your garden veg too!
