Butterflies are familiar, popular and colourful invertebrates that can be found in almost every habitat. They brighten our spring and summer days but are very sensitive to minor changes in habitat and climatic conditions.
Unfortunately a number of once common species such as the small tortoiseshell and wall brown are declining. However, other species such as the speckled wood are faring much better and are expanding their populations.
Moths are excellent indicators of the health of the environment as they are very sensitive to climatic conditions. They play a very important role in plant pollination as well as being an important food source for a range of creatures such as bats and birds.
Although some species are expanding their range, many moth populations are showing signs of serious decline. To better understand the reasons for these changes it is important to monitor the status and distribution of moths so that appropriate measures can be taken to conserve these colourful and fascinating insects.
It has never been easier to start surveying moths; the range of equipment on sale is extensive and reasonably affordable, there is a wealth of useful information on the internet, and modern identification guides are first class. Why not give it a go?
Or perhaps you can contribute your records to one of several national surveys.
How do I find out what invertebrates are using a chosen area?
There are a variety of basic techniques that you can use when surveying invertebrates in areas such as a garden, parish or wild space. All are effective and can be used to target groups of creatures living in specific habitats such as ponds, leaf litter, compost heaps and nettle beds.
Use survey form w to record your sightings.
Surveying invertebrates - How do I carry out a visual inspection of invertebrates in my chosen area?
You really do not have to look very far to start surveying invertebrates. Try going out into your garden with a notebook and listing what you see feeding on the flowers, crawling through the grass or sheltering under stones. For many small invertebrates it will only be possible to identify them down to family level in the field, because several species within a family group often look very similar. However, you can quickly learn to recognise some of the larger distinctive species by using a good field guide.
Trying the same thing at night will reveal a new cast of characters. Go out with a torch and you will find moths feeding where butterflies sipped nectar by day, cockchafers buzzing around cherry trees, colourful spiders in their webs hoping to ensnare hapless lacewings and large leopard slugs suspended from tree branches as they entwine in a mating embrace.
Use survey form w to record your sightings.
Surveying invertebrates - How do I set-up a pitfall trap to record invertebrates?
This is a very effective method of surveying invertebrates, especially beetles and spiders, which are ground-dwelling. Sink a small container, - a plastic cup, for example - into the ground until the rim is level with the soil surface. Invertebrates will fall into the trap as they move around the area and will not be able to climb up the smooth walls of the container.
The trap can be baited with meat, fish or fruit. To avoid the trap becoming waterlogged or overheated it should be covered with a raised stone or slate propped on small stones or such like. The trap should also be checked on a regular basis to ensure the inhabitants do not eat each other, and the whole trap should be removed after use.
Use survey form w to record your sightings.
Surveying invertebrates - How do I find out what invertebrates are living on the branches of trees?
The easiest and most efficient way of seeing what is crawling around in shrubs and trees is to place a white sheet or collecting tray underneath the target plant and then shake or gently beat the foliage to dislodge the creatures living on it. The creatures should be returned to the foliage when recorded.
When surveying invertebrates, use survey form w to record your sightings.
Surveying Invertebrates - How do I record the invertebrates found in grassland?
Perhaps the most simple way to sample areas of grassland and finer vegetation is with a soft, fine mesh net. Sweep through the area a few times to catch a representative selection of the invertebrates in that habitat (although try to avoid capturing fragile insects, such as butterflies). The contents can be emptied into a tray or onto a sheet for recording before being returned.
When surveying invertebrates, use survey form w to record your sightings.
Surveying invertebrates - How do I record aquatic invertebrates?
The best way to sample aquatic invertebrates is to sweep through the water and pond plants with a fine mesh net and see what you can catch! The net should be emptied into a plastic try half-full of pond water so that the contents can be examined and recorded. Do not leave your catch out of the water for too long a period, and gently return it to the pond once you have finished recording.
If you surveying invertebrates in a stream or fast-flowing, shallow beck, pick out one or two large stones and place them in a white tray with some water. After a short while you will see invertebrates moving around, such as mayfly larvae, flatworms and freshwater shrimps. Remember to replace the stones and the creatures back in the same area.
Use survey form w to record your sightings.
Surveying invertebrates - How do I find out what butterflies visit gardens or school wildlife patche
This kind of study is a great way of involving young people and the community in surveying invertebrates. Motivating people to record what they have seen, when they saw it, where it was seen and how many were present can provide important data on the distribution and abundance of the more common species year on year.
Ideally you should record the first and last dates you see each species as well as notes on any significant or sudden change in numbers.
Use survey form I
Surveying invertebrates - How do I find out what butterflies are present in my local area?
The standard method of surveying butterflies is very much like the transect monitoring of birds. Essentially a fixed-route or series of routes (transects) are selected and walked at regular intervals, ideally every week, during spring and summer. The route need not be too long - about 2km is a good distance - and can utilise existing footpaths, bridleways, quiet lanes and field boundaries. Record all butterflies seen along the route; over time this can build into a comprehensive record of species in the area.
Top tips for butterfly surveying:
- Try to include different habitats in your route. This will maximise the number of species likely to be seen.
- Make your visits between April and October on sunny, dry and calm days with a minimum temperature of 13 degrees centigrade (17 degrees centigrade if bright but not sunny). Butterflies are most active between late morning and mid-afternoon.
- Do not use a net to capture butterflies. Without specialist skills, the fragile insects might be harmed.
- Use a separate survey form for each visit.
- Always follow the same route.
- Before you start clearly record the date.
- Try to avoid double counting by walking steadily along your route and not stopping too long in any one place.
- Make a note of any habitat changes that take place through the year, such as hedgerow or grass verge cutting, localised flooding, fires, building development or anything else that you feel may have affected the count.
When surveying invertebrates, use Survey Form h.
Surveying invertebrates - How do I find out what butterflies are breeding locally?
Sometimes it will be quite obvious; clusters of small, black caterpillars on a nettle bed provide clear evidence that peacocks or small tortoiseshells are breeding. However, finding the larvae of other species may not be so easy and you will need to examine favoured food plants with a keen eye.
Gathering this information can be very useful, however, when considering potential development or management of an area. For example, mowing of grass verges can be planned to avoid damaging specialist food plants at critical times of the year. One good way to confirm breeding is to watch female butterflies visiting plants and checking closely whether she has laid any eggs after she has moved on.
When surveying invertebrates, use Survey Form h.
Surveying invertebrates - How do I go about recording night-flying moths?
To fully audit the species present at a given site it is necessary to attract moths at night when they are more plentiful and most active.
Moth traps
Moth traps are essentially big boxes with a bright light attached (usually a mercury vapour or actinic lamp), which most moths find irresistible. They are available commercially from a number of sources or can be made from a template.
These traps are very effective and over time will provide an excellent record of the moths inhabiting a given area.
When is the best time to set up a moth trap?
The best conditions for moth trapping are warm, overcast nights between the spring, summer and autumn months. However, moths can be found throughout the year and any mild, dry evening is likely to be productive.
It is best to avoid trapping on clear nights with a full moon, as the competing light sources result in fewer moths entering the trap; similarly, heavy rain and strong winds will result in poor catches and should be avoided.
Some species will favour a specific habitat - heathland or woodland edge, for example - and some have a very limited flight season.
Surveying invertebrates is a task which demands detail. To obtain a comprehensive record of moths inhabiting any given area it would be best to run the moth trap in every month and in all available habitats.
Do’s and Don’ts to moth trapping
Do’s…
- Do obtain permission from the landowner before setting up the trap on private land.
- Do ensure the moth trap is sited so as not to cause a nuisance to motorists, private residences or to navigation.
- Do ensure that the electrical components are constructed to comply with UK legal standards by a suitably qualified person.
- Do run the trap all night if in the garden. If the light is switched off during the hours of darkness most of the moths will escape.
Don’ts…
- Don’t run a moth trap in the same place too often, and certainly not on consecutive nights, as this could interfere with the moth’s breeding cycle or prevent them from feeding. It will also become a ‘bird table’!
- Don’t release large numbers of moths in a single place, as this will attract predators. Instead, let them go after recording and disperse them over a wide area of the garden, ideally in borders or dense cover, so that birds will not find them. This is vital if large catches in high summer are experienced.
- Don’t continue trapping if you see evidence of birds visiting the moth trap; if this occurs it is best to cease trapping in that area and select another location.
Surveying invertebrates - How do I go about recording day-flying moths?
You can look for moths during daylight hours. Several species fly by day and it is also possible to find resting night-flying moths by looking on tree trunks, sheds, walls and fences. Areas beneath street lamps, porch lights, garage forecourts and public buildings will often reveal species that would otherwise be hidden. Try looking on sallow blossom in spring and ripe or rotten blackberries and windfall fruit, as well as ivy blossom, in autumn.
Another method of daylight recording is to look for moth caterpillars. This is a reliable way of confirming a species breeds in a given area.
Try looking for droppings or damaged leaves on plants. This need not be as tricky as it sounds since the hawkmoth caterpillars, for example, deposit droppings (frasse) several millimetres in diameter.
You can search by:
- Close-up scrutiny of specific food plants.
- A more general sweeping of vegetation with a fine net.
- Suspending a white sheet beneath trees and shrubs and gently tapping the vegetation to dislodge the larvae.
As always when surveying invertebrates, certain things should be observed. Caterpillars should be handled gently or, in the case of the hairier caterpillars, not at all (some will cause a rash on sensitive skin), and returned to the vegetation after recording.
Do’s and Don’ts to moth trapping
Do’s…
- Do obtain permission from the landowner before setting up the trap on private land.
- Do ensure the moth trap is sited so as not to cause a nuisance to motorists, private residences or to navigation.
- Do ensure that the electrical components are constructed to comply with UK legal standards by a suitably qualified person.
- Do run the trap all night if in the garden. If the light is switched off during the hours of darkness most of the moths will escape.
Don’ts…
- Don’t run a moth trap in the same place too often, and certainly not on consecutive nights, as this could interfere with the moth’s breeding cycle or prevent them from feeding. It will also become a ‘bird table’!
- Don’t release large numbers of moths in a single place, as this will attract predators. Instead, let them go after recording and disperse them over a wide area of the garden, ideally in borders or dense cover, so that birds will not find them. This is vital if large catches in high summer are experienced.
- Don’t continue trapping if you see evidence of birds visiting the moth trap; if this occurs it is best to cease trapping in that area and select another location.
Use Survey Form j.
Surveying invertebrates - How can I make a sugar solution or wine rope to trap moths?
Two simple tricks you can use when surveying invertebrates:
Making a sugar solution
Making up a sugar solution is a very effective way of attracting a variety of moth species. Some species seem to ignore the conventional moth trap but will be attracted to the strong scents of such a sweet recipe. The mixture should be painted onto something like a tree stump or a fence post which can be inspected periodically to see what has turned up. A word of warning – the mixture is very pungent and very sticky and should not be used in situations where people will come into contact with it the following day.
Ingredients
500ml bottle of dark beer/stout
1kg dark molasses sugar
0.5kg dark treacle
Dash of rum
Vanilla essence
Method
Place the ingredients (except the rum) in a large saucepan and bring to the boil, stirring continuously. Let the mix simmer for 5-10 minutes and then allow it to cool. When the temperature has decreased add no more than 10ml of rum, thoroughly stir. Store the solution in glass bottles or jars and add vanilla essence just before deployment.
Making a wine rope
Wine ropes are lengths of thick string or mop heads that soak up lots of liquid and are immersed for a short while in a solution of red wine and either sugar or runny honey. The soaked bait is draped over branches or foliage at dusk. This will attract a range of species to feed.