Will the hungry caterpillar win the battle for your brassicas?
In the UK we have several species of ‘cabbage white’ butterflies: the Large White (above caterpillar), the Small White (below caterpillars), the Green-veined White and the dainty rare Wood White.
Whichever species is in our garden, I have given up trying to net
them off our cabbages as the result invariably looks like this, a
butterfly happily trapped inside the net…
Luckily there is a design flaw in the lifecycle of this elegant yet irritating butterfly…its eggs are bright orange, hence easy to detect and destroy. The eggs are usually found on the backs of your cabbage leaves. Once the caterpillars hatch they are much harder to spot, especially if they are the Small Whites which are exactly the same green as the plant.
I recommend checking your cabbages at least every other day because if you don’t catch the caterpillars in time, this is what happens to your crop:
The Good News
If you don’t catch the caterpillars in time and your brassicas end up being eaten to bits and looking like this, don’t worry – they will regenerate.
And the really good news is that when a plant is damaged by insect feeding, it senses the threat and springs into action, creating defense compounds to deter the pest.
Some of the defense compounds the plant produces are phenolic compounds and plant phenolics are reported to have anti-oxident and anti-cancer properties.
I have found several articles confirming that plants produce more phenolics when attacked by insects -for instance this research paper: frontiersin.org/articles/10.3389/fpls.2020.580753/full
What I haven’t found yet is anyone else making the conclusion that plants attacked by insects are more nutritious to us as they contain more phenolics.
If anyone knows more about this please do let me know!
More about Brassicas
A dislike for cabbage or broccoli can result from the fact that these plants contain a compound similar to phenylthiocarbamide(PTC), which is either bitter or tasteless to people depending on their taste buds.