Moths (and their caterpillars)
I have recently been helping Heal Somerset who are rewilding 460 acres near Witham Friary. I have been looking at their parking area with the view to making it a more attractive arrival.
My approach has been to analyse the existing plants in that area to understand better their contribution to nature, this starts for me by looking at the insects that visit them. I list all of the insects known to use the plant but initially much of my focus is given to butterflies and larger moths (macro-moths) as these are often more easy to visualise when communicating about a plant, especially, as it is often the case, the plant is either perceived as pernicious, usually because of its vigor, or seemingly insignificant, and so often considered a weed.
I have appreciated moths for a while, their names are often wonderfully descriptive as with the broad-bordered yellow underwing or frankly obscure like the Hebrew character.
Indeed, I did a moth survey, by leaving a lit moth trap in my garden overnight in July and had 86 moths visit of 48 different species in just one night. All this activity is happening when we sleep and we don’t even get to see it. Not just activity though, industry too. Dr Richard Fox, Head of Science for Butterfly Conservation stated in a recent article that ‘“research shows that moths are more efficient pollinators at night than bees are during the day”. This is quite a statement knowing that several moth species such as some of the hawk-moths don’t eat at all as adults, they don't even possess mouth parts. They just have to live long enough to breed.
Having done my moth survey I can now assess what plants they like to feed on as caterpillars and as adults, to help support them. Apart from making up the great richness that is nature, moths are, as has just been described, valuable pollinators but also with 97% of all terrestrial birds feeding their young on insects, their caterpillars are an important part of the food web for other creatures.
Some interesting insights have come up at Heal. Of the 20 plants found in this old milking yard between barns and milking sheds. One plant family and a couple of other plant species stand out as being ‘super contributors’.
With just the information on insect larvae and other phytophagous (plant eating) insects, the Polygonaceae family containing broad-leaved dock (Rumex obtusifolius) and prostrate knotweed (Polygonum aviculare), not the famously invasive Japanese knotweed but a small, unassuming, though it has to be said, spreading little plant, host a huge amount of moth caterpillars.
Broad-leaved dock supports 2 butterfly caterpillars, 59 larger moth caterpillars and 31 other insects including micro moth caterpillars, beetles and flies amongst others. A total of 92 insects that eat this dock.
Prostrate knotweed supports an incredible: 89 larger moth caterpillars and 23 other insects. A total of 112 insects that eat prostrate knotweed.
Trees as is often the case fare well with ash hosting 111 species of insect, 75 of which are larger moth caterpillars and grey willow hosting 58 moth caterpillars and a total of 185 insect species.
But let’s not forget the good old stinging nettle that put up against these other plants looks like a poor performer, merely hosting 36 moth caterpillars and 7 butterfly caterpillars. It’s worth mentioning that apart from ragwort and greater plantain that support moths in the low thirties, the next nearest plant (white clover) supported 16 moth caterpillars and then the rest were in the single figures. Nettle also hosts another 77 plant eating insects winning the prize in this round of ‘herbaceous plants - insect top trumps’, with a total of 120 plant eating insect species supported.
Without even looking at which adult moths and butterflies and other insects these plants support the nectar and pollen needs of, this is quite a tally for these hardworking plants that barely get a look-in in any developed or thought about landscape, often under appreciated and misjudged as messy or undesirable. I’ll not disagree that they can be challenging as has been proven by the title bestowed upon them as ‘weeds’ but, knowing the role that they play in contributing to nature, we might give them a little more space, both physically and in our hearts and minds?
This is certainly the approach I’ll be employing at Heal and the challenge I’ll be taking on, celebrating those everyday plants that give so much to nature. Wish me luck! :-)
Photo: Jeroen Voogd - UK Moths
