Thursday, 3 September 2015

Netted Carpet Moth Survey. (East Windermere) 2015.

The netted carpet moth is one of our rarest moths; its caterpillars or larvae depend on touch-me-not balsam, a 'nationally scarce' annual plant. It is their only food source. 

The Netted Carpet Moth (Eustroma Reticulatum) is classified as vulnerable in the Red Data Book and listed as a priority species by the UK Biodiversity Action Plan. Its main stronghold is within the Lake District.

Touch-Me-Not Balsam (Impatiens Noli-Tangere) with larvae in late August. Caterpillars pupate in the ground by October. Adults emerge in July and are 'on the wing' until mid August. The females lay eggs singly on the underside of the plant's leaves.

Since 1990 larval count surveys have been undertaken by Dr. Paul Hatcher of Reading University and John Hooson, National Trust  Wildlife and Countryside Adviser, with help from Trust staff and volunteers.

The fifth Quinquennial Survey started out at St. Catherine's near Windermere on September 2nd. and then covered the other East Windermere sites.

A caterpillar about to be photographed on touch-me-not at St. Catherine's by Academy Ranger, Pete.

The cool summer has delayed the caterpillars growth and development; many were exceptionally small and incredibly hard to spot. The larvae go through four stages of growth known as instars before they pupate. Usually by September the larvae are on their third or fourth instar. The one in the image is only on its first!

A rare find was this caterpillar on its third or fourth instar!

No Caterpillars were found at the Hodge Howe Wood site in spite of an intensive search!

Sadly, none were found at this large stand of touch-me-not, a previously unrecorded site.

Success! A caterpillar on the underside of a balsam leaf at the Birthwaite Road site.

A rare and unusual image of my clean fingernails! 
Seriously, it is showing a small larvae lunching on a small touch-me-not seed pod or capsule.

YIKES! This large caterpillar is the larvae of the elephant hawk moth and they are occasionally seen on touch-me-not. More often they are to be seen on willow herb.

Once the rest of the known touch-me-not sites have been surveyed an estimate of the current UK populations can be arrived at; this will give an indication of  how well the netted carpet moth is doing.

Related posts to this one are on this blog and tell the story of  National Trust rangers' conservation work involving the moth and the plant.

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