What is a white cabbage moth?
The white cabbage moth (Plutella xylostella) is also known by another common name, the 'Diamondback Moth'. This is because of its distinct diamond pattern on their wings. This is what makes it easy to tell the two insects apart from each other.
Cabbage moth eggs are also similar to that of cabbage white butterfly, with pale yellow, oval eggs. Cabbage moth larvae however, have certain characteristics, like curling into a horseshoe shape or hanging from a silken thread, which can help you identify it.
Which plants are impacted by white cabbage moths and cabbage butterflies?
Plants in the Brassicaceae family including:
- Broccoli
- Cabbage
- Cauliflower
- Canola
- Radishes
- Turnips
- Stock
- Alyssum
- Nasturtium
- Wild Mustard
- Wild Radish
- Shepherd’s Purse
How to protect your winter vegies from cabbage moths
Just as these two insects are slightly different in looks, they are also different in the way that they eat up your plants. Cabbage white butterfly larvae will initially chew small holes in leaves before growing larger and damaging more of the plant.
They tend to create irregular holes in outer leaves and the heads of broccoli and cauliflower, and if there are many of them, they can even strip the leaves back to the main vein.
Cabbage moth larvae, on the other hand, will feed leaves as soon as they hatch. They usually like to infest brassica head more than the butterfly larvae does as well.
Although different in damage, the prevention for these insects is the same, and mainly involves keeping a close eye on your broccoli, cauliflower and cabbage. Other pest control steps you can take include:
- Killing any weeds: removing brassica weeds like wild mustard and shepherd's purse means that there's a less likely chance of a cabbage moth or cabbage butterfly infestation in your vegie patch. This can be done simply by pulling weeds or spraying a general weedkiller.
- Setting up netting: using a fine mesh or netting over your plants that can be affected by cabbage moth or cabbage butterfly means that these insects will not even get the chance to lay their eggs.
- Remove plant material: caterpillars love any leftovers, and thrive in messy garden beds. A great way to reduce cabbage moth and butterfly infestation is by simply keeping everything clean and tidy.
- Remove caterpillars by hand: of course, if eggs have been laid and not removed in time, the best thing to do is get down and dirty and remove the caterpillars yourself.