Wednesday, 5 December 2018
The warm weather in May and June did produce a large emergence of our local comb-horned craneflies Dictenidia bimaculata and Ctenophora pectinicornis. In most years I get one or two records of these species at best but this Spring I had records from new sites and a very large emergence at Yardley Chase. They have the common name "comb-horned" as the males have antennae which bear two rows of branches, like the teeth of combs. The cranefly larvae live in rotting wood in mature trees, often high up in branches. The adults are occasionally seen near the ground after emergence. The comb-horned antennae are thought to be an adaptation to allow the males to find females by detecting their pheromones. In the tree canopy sensitive detectors would be needed to find a mate.
The reason for the sudden increase in records is probably down to the tendency for these insects to emerge in warm conditions.
Dictenidia bimaculata male showing the "comb-horned" antennae
Ctenophora pectinicornis female. This mimics a wasp but the projecting spike at the end of the abdomen is harmless. It is the ovipositor for laying eggs.
Neither species is very common. They are best looked for near ancient trees with rotten branches in woods or parks on warm days in late May and June. They often rest on tree trunks or nearby vegetation. Photos of them with details of location and date would help us find more sites for them. There are a few other comb-horned craneflies in Britain, some are extremely rare, so do try to photograph any you may come across. Photos can be posted on the Facebook WILDside Project Group.
Sunday, 8 April 2018
On Saturday, 12th May, John and Barbara Ismay and Jann Billker hold an Acalyptrate Clinic in the Collections area of the Oxford University Museum of Natural History. It is from 10 am to late afternoon. They will help you with the identification of Acalyptrata families (Diptera) to family level and many of these to genus or species. Please bring a few specimens that you find difficult or would like confirmed. The clinic is restricted to a maximum of 8 participants, so please let John and Barbara Ismay (email@example.com ) know if you would like to come. It would also be useful if you could let them know which families you are interested in. They will also bring some draft keys to smaller families that you could use.
I shall be holding a workshop at Pitsford Water on Sunday 22nd April. This will consist of identification of pre-pinned specimens and some field work. The balance will depend on the weather and attendees preferences. This is part of the WILDside project and attendees should contact Ryan Clark at the Northants Biodiversity Records Centre to book a place. The aim is to provide people who have already attended a fly identification workshop some practice as the season gets started.
Saturday, 16 September 2017
Before I was driven off by a heavy shower I noted some flowering ivy, always a good nectar source at this time of year. Two attractive hoverflies were visiting the flowers - Myathropa florea and Volucella zonaria. The latter is our largest hoverfly and has the common name of hornet hoverfly because of its close resemblance to and association with hornets. It only arrived in Northants in the mid 2000's but is now reported quite frequently, especially from gardens growing Buddleja.
Monday, 21 August 2017
I received the following email today. I know some dipterists have taken part and it is really easy. If you are interested in finding out more or taking part just follow the links. Many diptera species are aquatic in their larval stages. Some are very tolerant of high levels of pollution, for example Eristalis hoverfly larvae feed on bacteria in polluted water and have the 'rat-tail' breathing syphon that allows them to breathe fresh air whilst remaining in oxygen depleted water. On the other hand some soldierfly larvae are very sensitive to water quality and can be eliminated from a site by even minor pollution.
I’m writing to you from the Freshwater Habitats Trust to request your help to find clean unpolluted ponds, streams and ditches where wildlife can thrive.
Through our citizen science survey, Clean Water for Wildlife, we are supplying volunteers with simple kits that rapidly measure the water quality of local ponds, streams and ditches. Through the survey we hope to build a map of water quality across the country, find amazing clean (unpolluted) freshwater habitats where wildlife can thrive and to raise awareness of the true extent of nutrient pollution. Would you be able to help promote the survey to your group members? I hope this is something that is of interest.
Why is the survey important?
Clean unpolluted water supports rich and diverse communities of freshwater plants and animals, including many of our now rarest species. It is often the best indicator of a thriving waterbody. Despite its importance very little is known about the water quality in most freshwater habitats, particularly in our smaller waters. Until recently it was only possible to measure water quality through expensive laboratory tests, now with simple kits it takes just a few minutes. With new technology it is now possible to fill in the gaps in our knowledge and it presents an opportunity to find many more really special clean waters where wildlife can flourish.
The kits rapidly measure the levels of two widespread nutrients pollutants, nitrate and phosphate, and can be used in all type of freshwater habitats (garden ponds, ditches, streams, fens, rivers and more). With these quick kits people can now actively participant in current scientific research into water quality and help to discover clean water habitats where wildlife can thrive. You can see the kits in action in our short ‘How to Video’ (https://www.youtube.com/watch?v=63teHzPeX4M&t=4s)
For more information please visit
Please don’t hesitate to get in touch if you have any questions.
Freshwater Habitats Trust Project Assistant
(Please note I work on several projects and may be away from my desk for periods of time. This may mean there is a delay in my response)
Freshwater Habitats Trust, 1st Floor, Bury Knowle House, North Place, Headington, Oxford, OX3 9HY
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