Entomology Odonata survey 2022. In 2022 the Entomology Section has undertaken to conduct an “audit” of Guernsey’s Dragonflies and Damselflies [Odonata]. This has been prompted by a combination of factors including the continued drainage of sensitive sites and a lack of maintenance of others which leads to “pond progression”, a process whereby rotting vegetation increases the soil level eventually resulting in the loss of these sites. In recent times 11 species of Odonata, previously known to be present, have not been recorded. However all is not lost and if the habitat is available the island could be recolonised. In addition, with increasing temperatures forecast, new species could reach our shores.
It is important to not only identify the insects themselves but identify areas that are suitable for restoration. LSG have started this process at Le Grand Pre NR where three canals have been re-excavated. Further work is planned at Pre d’Enfer NR and the Silbe NR. This group of insects are particularly prone to herbicide, pesticide and nitrate pollution. With the demise of the greenhouse industry in the past few decades we had hoped that our streams were getting cleaner, however with Guernsey Water recently announcing that levels of pollution have increased significantly that, alas, is not the case. We hope that campaigns such as that launched by the Pollinator Project will result in the reduction of indiscriminate use of chemicals.
Emperor Dragonfly (Anax imperator) Blu-tailed Damselfly (Ischnura elegans) ACLMS and Guernsey Water have been very helpful in offering suggestions of where to search and arranging access to some of these sites. We also hope to survey areas that are privately owned, some of which have been good locations in the past. If you have a pond that you would like to be surveyed then please contact us at Entomology@ societe.org.gg. It is hoped that by the end of the year we will have gathered enough evidence to suggest where improvements are necessary and, in some cases, make suggestions where new habitat could be created. It should also be remembered that there is a huge amount of other insect life in a pond; Pond Skaters, Water Beetles, Caddis Fly larvae plus lots more.
If fish are present then areas that insects can retreat to are desirable. Even the smallest garden pond can be a haven for Odonata. Entomology would be delighted to receive details of your sightings, and if you have photographs of species you are unable to identify, then send them to the above email address and we will ID them for you. Trevor Bourgaize – Entomological Section Secretary