Friday 19 May 2017

Tiger Larva

Larva of Jersey Tiger, Euplagia quadripunctaria.  Hayes, 10 May 2017.
Larva of Jersey Tiger, Euplagia quadripunctaria.  Hayes, 10 May 2017.
 Look at this little beauty, which I found curled up among some bits of grass and other plants I was pulling up. 

Larva of Jersey Tiger, Euplagia quadripunctaria.  Hayes, 10 May 2017.
Larva of Jersey Tiger, Euplagia quadripunctaria.  Hayes, 10 May 2017.
It was curled up and took a long time to uncurl.  It's the caterpillar of a Jersey Tiger moth, a very showy creature that I see large numbers of in my light trap for a few weeks in early summer.  They used to be rare in this area, but no longer.

They are increasing in numbers.  Here's a post on Jersey Tiger moths from 2012, when they turned up in twos and threes.  Last year I had over 30 in my trap one day.

These caterpillars are not fussy about what they eat.

Bright colours are usually a warning to predators that the bright creatures are poisonous or distasteful.  Those hairs have a reputation for being very irritating.  They look a lot like the small spines on some cacti, that can get stuck in your skin and are indeed irritating, so I was not tempted to handle it.

I saw another caterpillar recently, and it's in this post of Jubilee Country Park photos.  That's what you would normally expect a caterpillar to look like.


Sunday 14 May 2017

Hawthorns

Midland Hawthorn, Crataegus laevigata, and Common Hawthorn, Crataegus monogyna.  Sevenoaks Wildlife Reserve, 25 April 2017.
Midland Hawthorn, Crataegus laevigata, and Common Hawthorn, Crataegus monogyna.
Sevenoaks Wildlife Reserve, 25 April 2017.
Most of the hawthorn bushes we see in the south of England are the Common Hawthorn, Crataegus monogyna.  The bush in the middle distance of this photo is one.  In the foreground is a less common species, a Midland Hawthorn.  Its flowers are just a little more showy than the common sort.  Also, the leaves are in general much less divided.  But this is not the best way to tell them apart.

Midland Hawthorn, Crataegus laevigata, and Common Hawthorn, Crataegus monogyna.  Flowers compared.  25 April 2017.
Midland Hawthorn, Crataegus laevigata, and Common Hawthorn, Crataegus monogyna. Flowers compared.  25 April 2017.
Common Hawthorns have just one stigma in the centre of each flower, and just one seed in the berry later on.  Midland Hawthorns have two or sometimes three stigmas, and two or three seeds in the berry.

Counting stigmas or pips is the only real way to be sure of these.  Because, as is so often the case, you might also come across a hybrid between these two species, Crataegus x media, which has leaves and flowers intermediate between them.  So on the hybrid, the flowers have mostly one, but sometimes two stigmas, and the pips in the berries follow suit.  Here is one we found in May last year:

Hybrid Hawthorn, Crataegus x media.  C. monogyna x C. laevigata. Near Jail Lane, 21 May 2016
Hybrid Hawthorn, Crataegus x media.  C. monogyna x C. laevigata. Near Jail Lane, 21 May 2016
They're common in some places, but often under-reported in the wild because not everyone goes around counting stigmas on hawthorn bushes.  I am told that they have been used in hedging because they are robust, but I have never found the common C. monogyna to be less than vigorous. 

Counting stigmas is MUCH easier than counting the pips, so this is the time of year to look for Midland or hybrid hawthorns them if you are so inclined.  Coloured and double-petaled forms of the hybrid are sold as garden shrubs. 

Wednesday 10 May 2017

Tentacular Spectacular

Bogbean, Menyanthes trifoliata. Sevenoaks Wildlife Reserve, 25 April 2017.
Bogbean, Menyanthes trifoliata. Sevenoaks Wildlife Reserve, 25 April 2017.
I had to post this photo of the flowers of Bogbean, a water plant in a small pool in Sevenoaks Wildlife Reserve.  The plant looks unexceptional for most of the year.

Bogbean, Menyanthes trifoliata. Sevenoaks Wildlife Reserve, 25 April 2017.
Bogbean, Menyanthes trifoliata. Sevenoaks Wildlife Reserve, 25 April 2017.
It has a short flowering season, so normally you just see these leaves.  But those petals covered with tentacles are amazing.

You can see some of the plant in the background of this photo I took of the same pond in September last year:

New Zealand Pigmyweed, Crassula helmsii.  Sevenoaks Wildlife Reserve, 2 September 2016.
New Zealand Pigmyweed, Crassula helmsii.  Sevenoaks Wildlife Reserve, 2 September 2016.
This photo is of an invasive foreign plant, New Zealand Pigmyweed, which covers most of the edge of the pond.  It has pretty little flowers:

New Zealand Pigmyweed, Crassula helmsii.  Sevenoaks Wildlife Reserve, 2 September 2016.
New Zealand Pigmyweed, Crassula helmsii.  Sevenoaks Wildlife Reserve, 2 September 2016.
But unfortunately it chokes and outgrows any native plant that likes the same habitat.  Here's a quote from the Non-native Species Secretariat:

"Introduced in 1911 as an oxygenating plant for ponds and, since the 1970s, has spread rapidly. Forms dense mats and can impede drainage, causing flooding. Displaces other aquatic plant species and reduces amenity use of the waterbody.

New Zealand Pigmyweed is listed under Schedule 9 to the Wildlife and Countryside Act 1981 with respect to England, Wales and Scotland. As such, it is an offence to plant or otherwise cause this species to grow in the wild."

Friday 5 May 2017

Some JCP Photos

Scots Pine, Pinus sylvestris.  Jubilee Country Park, 30 April 2017.
Scots Pine, Pinus sylvestris.  Jubilee Country Park, 30 April 2017.
There was a lichen walk in Jubilee Country Park last weekend, led by Ishpi Blatchley, or local lichen expert.  I took the opportunity to take some photos of a range of subjects .. this one shows the male "cones" of a Scots Pine, shedding pollen.  There are lots of little pollen grains stuck to the sort of spider webbing which you can find almost everywhere in the countryside.

Oak Apple gall.  Jubilee Country Park, 30 April 2017.
Oak Apple gall.  Jubilee Country Park, 30 April 2017.
There were several of these galls, looking large and apple-like, on an oak tree that was right behind Isphi as she gave her introductory talk.  I was itching to take a shot but waited until later as that seemed more polite!  These growths are caused by the aptly-named  Oak Apple Gall Wasp, Biorhiza pallida.  There are hundreds of plant galls caused by a range of insects that make plants grow homes for them.  Oaks have more types of gall than most plants.

Larva of Orthosia cerasi, Common Quaker. Jubilee Country Park, 30 April 2017.
Larva of Orthosia cerasi, Common Quaker. Jubilee Country Park, 30 April 2017.
This caterpillar was munching on a Field Maple at the edge of the car park.  It was identified for me later (caterpillars are hard!) as a Common Quaker,  a type of moth that is easy to find early in the year.  I was pleased to get a shot that showed the head and the whole body structure so clearly.  It's not as easy as you might think, because they keep on the move and their heads go from side to side.

Parmelina pastillifera.  Parmeliaceae.   Jubilee Country Park, 1 May 2017.
Parmelina pastillifera.  Parmeliaceae.   Jubilee Country Park, 1 May 2017.
Finally, an actual lichen!  Ishpi was pleased to find this Parmelina pastillifera as she only has three other sightings in the London Borough of Bromley (though it's not rare in the UK as a whole).  This was on an oak branch and Ishpi was drawn to it by its steely glint. 

Parmelina pastillifera.  Parmeliaceae.   Jubilee Country Park, 1 May 2017.
Parmelina pastillifera.  Parmeliaceae.   Jubilee Country Park, 1 May 2017.
I wasn't happy with the photos I took on the day so I went back the next day to improve on them.  I opened the iris and sped up the shutter.  This gives less depth of field, but better sharpness and less motion blur.  (As I take these one-handed, holding the subject in place with my other hand, motion blur can be a problem, especially on a long springy tree branch.)

Those little bumps are isidia, little outgrowths containing both the fungus and alga component of the lichen.  It can reproduce if these growths break off and are scattered.  Their shape on this specimen helps to identify it.