It was late July when I received an email from a local moth expert, Brian Hancock, inviting me to go along to a local woodland one evening to see if we could find specimens of the adult Netted Carpet (Eustroma reticulatum). When I first set out on my mothing journey, Brian got in touch and invited me round to his house, socially distanced and outside of course, he lives just over the border in North Lancashire. I had never met Brian before, although we both volunteer at RSPB Leighton Moss, our paths hadn’t crossed. However, I have a number of small publications about the wildlife in our local Area of Outstanding Natural Beauty (AoNB) of which Brian authored and acts as recorder of the species seen. He has also written an excellent book about Pug moths (Pug Moths of North-west England – available from the Lancashire & Cheshire Fauna Society). Brian advised me on various things to do with mothing and invited me along to meet the mothing team at RSPB Leighton Moss once things got going again after lockdown. I duly went along and am now a valued member of the volunteer mothing team, regularly checking the trap and recording the moths we find, I’ve even been let loose on my own a couple of times now. It was apparent early on that this journey into the world of moths is not just about spotting the moth itself but rather learning about the habitats they can be found in, where and when to find the food plant but also which rare moths survive in specific areas locally and the conservation efforts in place to safeguard their future. I have Brian to thank for encouraging me to delve deeper into this world, I am grateful for him sharing his enthusiasm for the subject along with his knowledge and experiences.

I had not seen a Netted Carpet before, so thought it best to at least have a look in the field guide (Field Guide to the Moths of Great Britain and Ireland, Third Edition, Waring et al 2017) for it. It is quite a small moth with a forewing of one and a half centimetres, with a network of white lines on the forewings, on a dark background. Whilst looking in the field guide I noticed the initial RDB, just above the distribution map. The highlighted area on the map was tiny suggesting a very localised population nationally. The letters RDB illustrate that the Netted Carpet is a Red Data Book (RDB) species. The RDB in question is the British Red Data Book number 2: Insects published by the Nature Conservancy Council 1987, I duly picked up a copy of the book from an online auction website. Red Data Book is a state document established for documenting rare and endangered species of animals, plants, and fungi, listing the threatened species. I noted that the species can be found in the wet parts of woodland and favours the Touch Me Not Balsam (Impatiens noli-tangere) as its food source both as an adult and as a larvae. The adults can be found in flight from early July to mid August. Like most moths they are nocturnal and come to light traps. They are also, univoltine, which means they have one brood a year. In 1987 it was recorded that Netted Carpet can be found at nine sites in the Lake District. Since 1987 the Netted Carpet has been listed as vulnerable in the RDB. Populations can be affected by factors such as habitat loss, change of land use and the availability of the foodplant. This has led to conservation efforts taking place to not only protect the habitat but to promote the growth of the species in the areas it is found in. The survey I was invited to in the local woodland was to locate and count the numbers of adults among the patches of Touch Me Not Balsam. Such is the importance of the foodplant that it was important to take the utmost care when searching for the specimens. One cannot simply charge around like a bull in a china shop and tread on the foodplants, a more delicate approach was necessary. At dusk we set out carefully trying to locate the moths by the light of our headtorches, Brian set up a portable trap up to see if any of the adults came to light, a small number were recorded this way. Very quickly an adult was spotted alighting on a moss covered log, much to the excitement of the small group of moth-ers present. During the search we found a good number of adults spread out over the woodland area, the adults were found in the areas where the Touch Me Not Balsam has been encouraged to thrive as a result of some excellent conservation work to promote it’s growth.

Netted Carpet (Eustroma reticulatum)

As September approached, Brian mentioned that it was the time of year for the annual Netted Carpet larvae count at the local site and would I like to join the survey team with the hope of seeing the small larvae on the foodplant. Obviously I jumped at the chance to take part. We met up at the woodland and techniques in searching for the larvae were exchanged. We then went off into a small patch of Touch Me Not Balsam and carefully, bottoms in the air, searched for the larvae. It wasn’t long before a shout went up “found one”. Brian was the first to find a larvae so I went over to have a look, having never seen one in the flesh before, at least now I knew what I was looking for, I even managed a half decent photograph on my phone. It was apparent that this search was going to be difficult, the larvae blend in very nicely with the stems of the plant making them very hard to see, perfect camouflage. Nevertheless, after searching a few plants I managed to find a larvae by myself, my first one. I found two in total that evening of which I am quite proud. Overall, a good number of larvae were found across the patches of Touch Me Not Balsam in the woodland, this indicates that the population is sustaining itself.

Netted Carpet larva
Netted Carpet larva on the delicate Touch Me Not Balsam
A damaged seed pod indicative of feeding by the larva

When I got home that evening I did wonder if there was an easier way of detecting the larvae on the foodplants. It was difficult maneuvering around in the dark trying desperately not to damage the plants. It occurred to me that I had read somewhere that some larvae fluoresce under UV light and wondered if these larvae did the same. Only one thing for it, I purchased a simple UV torch from an online retailer with next day delivery and waited patiently. My new torch arrived the next day complete with instructions on how to use it best for locating pet urine on a carpet! I set out that evening, back to the woodland and straight to a spot where I found a larva the previous night. There it was, in the same spot. I waited until darkness fell and low and behold the larvae fluoresced right before my eyes, a single stripe of brightness extending along the length of the body. Hopefully we can use this technique in the future to help us locate more larvae and further study the progress of the local Netted Carpet populations. We just need a more powerful UV torch.

Netted Carpet larvae fluorescing under UV light

I hope to return to the woodland in the year to take part in some of the conservation work necessary to the survival of this vulnerable local species. I’ll let you know how we get on.

Cheers for reading and if you have any questions, please get in touch.

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