What am I?  I am drawn to the light but fly mostly at night…  I have scales on my wings and I’m silent in flight…  I am a pollinator who can mimic the flowers I feed on and I drink their nectar through a straw like proboscis that curls…

I…

am…

a Moth!

It becomes kind of addictive after a while.  It’s the butterflies in your stomach feeling, pre-present opening on Christmas day when, on a crisp morning before the sun pours into the gorge, you gather round the trap instead of the tree, not knowing what delicate treasures might be lurking within the egg boxes inside.

With help from one of Butterfly Conservation’s Moth Recorders’ Jo Davis, who sets a Robinson Trap on our Falls of Clyde reserve once a month, we carry out surveys between March and October, and for myself and the volunteers that join us, it is always a delight.  We primarily monitor the diversity of moths because they act as what are called indicator species, which give us an idea of how healthy or unhealthy the environment is…a little like the canary in the mine.  The bonus of being able to get this close to them is that they are absolutely fascinating, and in some cases even more beautiful and intricate than their daylight cousins, the butterflies.  For nature lovers, they are art.

In the UK, around 60 species of butterfly have been recorded compared with a whopping 2500 species of moths, so as you can imagine, the evolution of colours, shapes, sizes and defence mechanisms is vast.  The intricacies of moth physiology and ecology is something quite beautifully complex.  One example of a moth found at Falls of Clyde which uses defensive markings is the gold spangle (Autographa bractea), pictured above.  It  has beautiful silvery metallic marks on its wings, which when it occasionally flies during the day, disorientates potential predators with a flash of light.  Interestingly, there are actually more colourful day flying moths, than butterflies altogether, which only fly during the day (Ref. 1), and for the purpose of trying to draw you over to the dark side, I will be highlighting a few more of the eye-catching species I have found at Falls of Clyde.

The next brightly coloured moth to marvel at is the garden tiger (Arctia caja), which has developed some pretty amazing ways to evade predators.  The first thing to note is their tiger like patterning and bold orange underwings.  This is not just for show!  The moth uses the brightly coloured underwings in its defence, by flashing them at a potential predator, thus giving them a bit of a shock in the hope that this would be enough to scare them off.  What if it doesn’t work?  Don’t worry, the tiger has a few more tricks up its proboscis!  These bright colours are a form of aposematism, which basically means a warning sign.  Just like a bright red stop sign or the yellow and black stripes on a wasp, they communicate to predators that they are potentially hazardous.  And this moth is not kidding.  If threatened it can produce a foul-tasting yellow liquid from ducts behind its head, which can also act as an irritant if it comes into contact with human skin (Ref. 3).  Garden tigers and other members of the tiger moth family (Erebidae), have also been found to have the ability to emit sound!  Specifically, ultrasonic clicks which incredibly, interrupt or ‘jam’ the sonar calls of bats, which are one of their main predators.  In doing so, the bats are unable to accurately locate objects and gauge distances, hence allowing the moth to evade their grasp (Ref. 4).  Very clever.

The next marvellous moth, is a master of disguise.  This beauty can blend effortlessly into its woodland habitat, in order to deceive predators on the prowl for an easy meal.  The merveille du jour (Dichonia aprilina), translates to ‘marvel of the day’ and it is a firm favourite.  Its mottled light green and black patterning allow it to quite literally disappear onto a lichen backdrop, a fantastic example of evolved camouflage (see pic).

Did you know that the colours that you see on a moth’s wings and the dust that is left on your hands if your handle one, are actually scales!  So, you could even speculate that moths are like tiny vegan dragons…minus the fire too obviously! Maybe a bit too far fetched…

The name Lepidoptera, which is the group that encompasses all butterflies and moths, literally translates to ‘scale wing’, and the plethora of patterns that you see when you look at their wings is actually down to…science alert…light diffracting through a delicate structure of ribs and holes on the scales (Ref. 5).

So far we have seen moths which demonstrate camouflage, chemical defence, sonar jamming, and aposematism, and the last moth I would love to share with you is an incredible example of mimicry.  The buff-tip (Phalera bucephala) literally looks like a broken birch twig (See pictures below).  This marvellous wee beastie easily falls under the category of ‘moths that mess with your mind’!  Which is exactly the point…if you’re a bird!  If you don’t look like food, then nothing will try and eat you.  Genius.  This kind of adaptation arises from the predator-prey dance, with predators constantly applying selection pressures, which trigger physical adaptations over time…to survive they must continually evolve.

This short blog was just the tip of the ice-burg when it comes to the awe inspiring world of moths.  If you would like to explore more at home there are plenty of ways to safely capture and admire them.  It can be as simple as shining a torch on a white sheet at night, between spring and autumn.  Alternatively, try contacting your local Butterfly Conservation recorder or Scottish Wildlife Trust reserve.  If you live locally to Falls of Clyde and would like to join us in the spring, please get in touch via fallsofclyde@scottishwildlifetrust.org.uk.

Happy wintering.

Nicole, Clyde Valley Ranger.

References

Ref. 1: Identifying Moths by Butterfly Conservation. Available at: https://butterfly-conservation.org/sites/default/files/identifying_moths-factsheet.pdf (Accessed 29/11/24)

Ref 2: WELLER, S.J., JACOBSON, N.L. and CONNER, W.E. (1999). The evolution of chemical defences and mating systems in tiger moths (Lepidoptera: Arctiidae). Biological Journal of the Linnean Society, [online] 68(4), pp.557–578. doi:https://doi.org/10.1111/j.1095-8312.1999.tb01188.x.

Ref.3: Garden Tiger Information| Butterfly Conservation.  Available at Garden Tiger | Butterfly Conservation (Accessed 2/12/24)

Ref. 4: Yong, E. (2009). Tiger moths jam the sonar of bats. [online] Science. Available at: https://www.nationalgeographic.com/science/article/tiger-moths-jam-the-sonar-of-bats [Accessed 6 Dec. 2024].

Ref. 5: www.sciencefocus.com. (n.d.). What’s the powder on a moth’s wings? [online] Available at: https://www.sciencefocus.com/nature/whats-the-powder-on-a-moths-wings.

‌