Geographical Variation

One of the Mothathon experts from Chester, which is to the north of Wales, noted that he had already trapped in that area 36 times, from the beginning of the year, up until the Mothathon. This had yielded 240 different species so far. As a comparison, trapping over a single weekend at the Woodland Education Centre, near the southern coast of England, yielded 178 species. This represents 75% of the total number of species trapped over several months in Chester, in a single weekend at the Centre.

	Individual moth species can have a very localized distribution. The record of Feathered Beauty (left) on both nights of the Mothathon created an interesting discussion. This was due to the fact that Feathered Beauty, which is thought to be a migrant, has previously only been recorded in Kent, Sussex, Surrey and Essex. It has never been recorded in Devon before. This species can be confused with the very similar species, Willow Beauty. Differences in the antennae of the males help with separation of the two species.
	.
	The Devon County Recorder for moths, Roy McCormick, was therefore interested to verify the record. He arranged trapping at the Centre several days after the Mothathon, in the hope of finding Feathered Beauty.

The species was not trapped on this occasion, but it must be pointed out that this does not mean that it was not trapped over the Mothathon. Enormous variations in species catch are possible when trapping on different nights and even at slightly different locations. The absence of Feathered Beauty on that night is therefore not confirmation of its absence over the Mothathon.

To put this in perspective, Elephant Hawk-moth was not found by the County Recorder's team, but no-one would suggest that this means the species is absent from the Centre. In addition, although Feathered Beauty was not found on the night, the County Recorder's team did trap a new moth for Devon, called Crambus silvella. For more on this click here

Several specimens of another Feathered Beauty look-a-like, Satin Beauty, were also trapped on the night of the County Recorder's visit. Satin Beauty is normally slightly larger than Feathered Beauty. However, the specimens trapped on this occasion were all small, well-marked specimens which could be confused with Feathered Beauty.

Both Feathered Beauty and its look-a-like species Willow Beauty, were separately recorded over the Mothathon (although Satin Beauty was not). The records involved relatively large numbers of each species (28 and 22 respectively), so that the record of Feathered Beauty is not based on a single specimen. The Mothathoners were experienced experts who had access to all the necessary identification guides and surprising records such as this were carefully checked.

A definitive decision awaits, but based on the evidence, future trapping in the same area over the right flight time may well increase the known distribution of Feathered Beauty. 

The recorded distribution of individual species is partially a combination of the actual distribution of the species, together with the success of people at finding the species in a particular area. This latter is obviously dependent on the amount and timeliness of trapping being done in the area, as well as on the identification skills of the trappers. Moth trapping has greatly increased in popularity over recent years, so geographical species records are constantly being swelled. However, it is worth bearing in mind that failure to trap a species in a particular area does not necessarily mean it is absent. What is caught often depends on being in the right place at the right time.

Local Variation

It is not only moths which are attracted to light. A great variety of other insects will usually also be found on examining the traps. Traps near water had large numbers of adult caddis flies. Hoverflies, diving beetles and water boatmen are sometimes also attracted to the light. The traps located on the bridlepath, behind the Heathland Project area, attracted large numbers of froghoppers and terrestrial beetles  which were not noted elsewhere.

A Caddis Fly (also known as moth flies). These have hairy wings and can resemble moths, although the lack of a proboscis and the very long antennae usually pick them out. They are common visitors to light traps.

Other catches besides moths in the traps also included hornets, (which can denude the moth catch by eating all the moths before the moth trapper arrives to liberate them in the morning!), a Red Admiral butterfly, wasps, midges and mayflies. Later analysis of the moth catches according to trap will no doubt also yield a variety of differences in the moth catches according to trap location.

Butterflies   

As an illustration of the difference between the number of moth and butterfly species in Britain, 14 species of butterfly were recorded at the Centre on the 27th July, as opposed to 125 moths.

These were:

For more on butterflies found at the Centre, click here.

MOTHATHON CONTENTS