Monday, October 5, 2015

In Praise of Devil's-bit Scabious

Devil's-bit scabious Succisa pratensis must be one of the best of all late summer wild flowers for providing nectar for butterflies and moths. It has a long flowering period, from late August onwards, and attracts a wide range of lepidoptera including.....

... small white butterflies ...

.... small coppers ....

... several moths, including the silver Y, an immigrant that often arrives in large numbers when the scabious is at peak flowering.... 

... peacocks ....

... red admirals .....

... and small tortoiseshells

It's an easy plant to introduce into a wildlife garden but seeds need to be collected as soon as they begin to ripen, because these rather attractive heads of seed begin to fall apart and scatter as soon as they begin to dry out. I germinated seed last autumn which are now robust plants that should flower well next year.

Thursday, October 1, 2015

Small Coppers: warm colours and fiery temperament

Today's Guardian Country Diary is about small copper butterflies.

This last week of unbroken sunshine has produced some excellent opportunities to watch these lively little butterflies. This was one of two contesting a sunny, south facing slope on the moorland edge near Stanhope in Weardale, where some heather was still flowering.

These are amazingly aggressive little butterflies and this individual rose several times from its favourite sun-bathing stone to chase off its rival. What really surprised me was how fast and furious these aerial battles are - I've often watched fighting male butterflies but this was the first time I had seen and heard a clash of wings.

The lower slopes of heather moorlands offer some of the best opportunities for watching the late summer generation of small coppers in Weardale because there is plenty of nectar available from heather flowers and also usually plenty of sorrel, their larval food plant. It seems to be especially prolific in the year after heather burning, maybe because the minerals in the ash promote very vigorous sorrel growth.

The other abundant nectar source for them at this time of year at lower altitudes is devil's-bit scabious, which has a long flowering period. 

Tuesday, September 29, 2015

Tandem dragonflies

We spent a fascinating afternoon recently watching dragonfly behaviour at Ashes quarry at Stanhope in Weardale.

The most numerous dragonflies in the shallow, moss-edged pools there are common darters, Sympetrum striolatum. We watched them on their egg-laying flights, where the male tows the female around, attached by the tip of his abdomen to a point just behind her head.

Coupling up like this is the male's way of defending the female he has inseminated, preventing rival males from mating with her and displacing his sperm.

It's an unwieldy arrangement. At frequent intervals the male lowers his abdomen, forcing the female down to the water surface where she drops fertilised eggs from the tip of her abdomen.

That's an awkward manoeuvre, when the male momentarily hovers in this vertical position.

The males are fiercely defensive of their territory, often perching on a favourite stone or ....

... plant stem, ready to drive off rivals and pursue any passing female.

The second commonest dragonflies at this site are black darters Sympetrum danae. There seemed to be quite a lot of interspecific aggro - we watched several aerial battles between the two species.

These dragonflies land with their wings outstretched but ....

... finally come to rest with them in this swept-forward configuration.