CONTINUING THE SEARCH FOR LAND CADDIS ENOICYLA PUSILLA

Harry Green and Brett Westwood.

Since our report in Worcestershire Record No 13 November 2002 page 28 we have been able to search several new areas in west Worcestershire and now have records from 150 1x1 km squares. In addition the moth trappers in Wyre Forest have recorded the larvae entering traps on several occasions and have provided accurate location reports from several sites in the Forest and also for Ribbesford Wood. It is not clear why the larvae are entering the moth traps. They may be simply crawling in when the trap is placed on the ground over them or perhaps they are attracted to the light, although the latter seems unlikely. Nevertheless the records are useful and it would be helpful if all moth trappers kept a look out for them and sent us records.

Caddis larvae were also found along the Dick Brook near Joan's Hole in April. In this case many larvae were found crawling on mosses and dead leaves a few feet above the stream. It is perhaps surprising that they should be found so close to a stream prone to flooding. Perhaps they can survive watery immersion for a while and the stream may transport them to new locations. Land Caddis larvae apparently survive best in leaf litter where the relative humidity is between 70% and 100%. When it is too dry they move downwards through leaf litter and possibly into cracks in the ground to find moister conditions - we discovered that it was very difficult to find them during the very dry spell in April this year. After rain and heavy dew they have been seen to swarm upwards onto brambles or tree trunks and "hang out to dry", returning to leaf litter as they dry out (Harding 1995). Those seen at Joan's Hole hay have been drying out after rain.

If anyone finds land caddis please let us know. If you have not seen land caddis before we should like to see your find to check identity. Certain micro-moth cases have occasionally been mistaken for land caddis in the past.

Both Nigel Stone and Rosemary Winnall lave taken to excellent pictures of land caddis recently and are included here - many thanks to you both and apologies because converting them to black and white and then photocopying theem does not do them justice, but it's the best we can do!.

Reference
HARDING DJL 1995 Land Register for a caddis larva?

 
Above: Land caddis case with spines on larval head showing on the left. Actual size about6 mm long. Photo Nigel Stone
Right: Land caddis larval head. Photo Nigel Stone
Below: Land caddis walking. Photo Nigel Stone
 
Above: Land Caddis from Joan's Hole. Photo R. Winnall

 

 

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