One of my favourite jobs as a warden intern here is light-trapping and identifying our moths. We have thousands of species of moth here in the UK, and many are found in the Aire Valley reserves. Moths are mysteriously drawn to light, particularly light that is rich in ultraviolet and at times when the moon’s light is weaker. This is called “positive phototaxis,” and means moths are drawn to traps and once there they plunge into a funnel and into a refuge, traditionally of egg-boxes, which provides them some safety until inspection.
Moth trapping doesn't have to be difficult! A brilliant way to learn and see what you can attract is with a torch and bed sheet. Image: Nick Cunard (rspb-images.com)
Moths – an ID challenge!
Moths and Butterflies form a group known as the Lepidoptera, meaning “scale-wing.” Care must be taken when handling these creatures to prevent these dust-like scales from dislodging.
Not all butterflies are brightly-coloured or all moths nocturnal and drab; a more complex combination of features (of antennae and wing-coupling) is used to distinguish between the species.
Not all moths fly at night - this six-spot burnet flies in the day and flaunts its colours as a reminder of its foul taste to predators.
This classification is not straightforward; imagine a florist cutting several stems from a single plant and then adding other flowers to the same vase – this is an analogue for how the tree of life has often been “cut” in classifications of convenience by the biologists of the past.
It is better to enjoy the group as a whole than to overstress the differences between the widely-appreciated butterflies and the often-subtler moths.
Distinctive species such as the hawkmoths provide an opportunity for beginners and contain some tougher species too. Some of these are so hard to identify, even the experts have named them with descriptions such as ‘confused’ and ‘uncertain’!
The elephant hawk moth, found at Fairburn Ings, gets its name as the caterpillar has a protuberance that resembles a trunk!
The diversity of markings is hard to put into categories and often distinctive features are shared by many species. Some species show variation even amongst freshly emerged adults and all species may lose features with age; understanding this variation is important for identification.
One challenge is to find where in the book to look for the creature in question - there are sometimes several “islands” of similar looking creatures to work out!
Bright-line brown-eye moth - not to be confused with the brown-line bright-eye of course
Caterpillars and plants - at war As a plant ages it creates poisonous compounds. It is a race for caterpillars to eat enough whilst their chosen plants are still edible and nutritious – otherwise they will never reach cocoon stage.
In retaliation, some plants chemically advertise their caterpillars to parasitoid wasps which lay their eggs upon or even inside them so that their larvae can consume them.
This buff-tip moth goes to show that even cryptically marked creatures can be beautiful!
Timing and emerging moths
Different food plants, soil nutrient-levels, climate conditions and day-length influence moth maturation rates., which means different species emerge and fly in different months of the year.
Understanding our moths and when they emerge gives us a fine-grained sense of season that is of incredible scientific value in understanding climate change.
Week-by-week new species emerge and the superb Yorkshire Moths- Flying Tonight website can tell you what to expect and when. A huge help given the 2500 species of moths we have in the UK!
Pug moths are notoriously difficult. I photographed this one with a page of a book - possibly the wrong page!
Moths and conservation
This enormous group is diverse and widely-studied and so provides an excellent measure of our attempts to conserve the natural world.
If we can protect this group of species, for example by preserving wild herbaceous borders, we will also pass on benefits to other creatures whose niches are part of or overlap the ones occupied by these beautiful creatures.
For a great opportunity to identify moths and use a professional moth trap this summer - see Big Wild Sleepout at Fairburn Ings this weekend! http://bit.ly/2soAieEWild Wednesdays held every Wednesday in August will also feature a moth event - please stay posted or ask us on social media for specific updates. http://bit.ly/2u3koYp