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Ash dieback - what to do?  Pre-empt, plant, persevere, keep calm and carry on.

Ash dieback – what to do? Pre-empt, plant, persevere, keep calm and carry on.

by Richard ~ 30 October, 2012 ~ 5 comments

The last ice age endured for about 100,000 yrs.  Some 18,000 yrs ago, mammoths, sabre-toothed tiger and woolly rhino (preyed on by prehistoric man) roamed our land.  Thick ice sheets lay to the North, whilst to the South was tundra – much like that now seen in Northern Siberia. Then 10,000 years later, the ice sheets started to melt and the tundra receded; sea levels rose and low lying areas were flooded.   The North Sea and English Channel formed, cutting us off from mainland Europe. This was a gradual process (in our terms) and as Europe warmed,  trees migrated northwards – some reaching the UK before we were cut off from the rest of Europe.  Most plant colonisation was by seed and spores, animals followed bringing with them other taxa. Read more…

Horse chestnut leaf miner moth - help needed

Horse chestnut leaf miner moth – help needed

by Lewis ~ 11 September, 2012 ~ 5 comments

The leaf miner moth (Cameraria ohridella) that arrived in the UK about a decade ago has spread widely, and many horse chestnut trees have been ravaged by its activities (see related posts / links). The brown, lifeless leaves that dangle from the branches in late summer are a clear sign of the activities of this insect.  It had been hoped that certain parasitoid wasps might help control the leaf miner, but this is not the case. There is now the suggestion that birds, like blue tits, might help.

Read more…

The harlequin ladybird

The harlequin ladybird

by Chris ~ 18 March, 2012 ~ one comment

Some six years ago, there was a post about the harlequin ladybird  (Harmonium axyridis)– aka Multicoloured Asian Ladybird and the Halloween Ladybird – a ‘newcomer’ to these isles, and which might prove to be a threat to the native species.  The harlequin ladybird in an Asian species that has been used for pest control (aphids etc).  All ladybirds are beetles.  They belong to the order – Coleoptera – and are characterized by having forewings modified as hard wing covers or ELYTRA and biting mouthparts (cf. butterflies and moths).

Now some years later, research by scientists at the Centre for Ecology and Hydrology have evidence of strong link between the arrival of the harlequin ladybird and the decline in other species of ladybirds.  Seven out of the eight native british species have declined – with some now described as being ‘near the threshold of detection’; similar issues have arisen in Belgium and Switzerland where the harlequin ladybird is also present. Read more…

Signal Crayfish

Signal Crayfish

by Lewis ~ 2 March, 2012 ~ 2 comments

Plants and animals from different parts of the world are being ‘mixed’ up as worldwide travel by train, boat and plane increases year by year.  The woodlands’ blog has reported on a number of plants and animals that are regarded as ‘aliens’ or invasive species, for example, the ‘killer shrimp’.  Sometimes the ‘concern’ proves to be unfounded, but the arrival of various pathogens can be problematical for ‘native species’.

At some point back in the 1970’s, the North American signal crayfish arrived in the U.K.   Since that time it has spread through various river systems, particularly in South and South East England, at the rate of 2 km per year (approx.).   Its spread may have been assisted by damp fishing gear.  It would seem that the signal crayfish is out-competing the native white clawed crayfish (that is, native to Europe, including England, Wales and Ireland – but not Scotland). Read more…

The holly leaf miner : Phytomyza ilicis

The holly leaf miner : Phytomyza ilicis

by Chris ~ 18 January, 2012 ~ Comments Off

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Phytomyza ilicis is a dipteran fly that lays its eggs in holly leaves.  It is one of the few insects that is able to make use of holly leaves as a food source / habitat.  The female fly lays eggs in the holly leaf (near the main veins or midrib – on the underside) using a thin tube or ovipositor.

The eggs are usually laid in early Spring when there are young and ‘soft’ leaves.  Older leaves have a thick and tough cuticle that is far more difficult to penetrate.  The larvae or maggots emerge from the eggs and tunnel their way along the midrib / veins emerging some time later into the lamina or blade of the leaf.  Here they feed on the photosynthetic tissues of the leaf – the palisade and mesophyll layers, creating a leaf mine (see featured image).  The number of leaf mines per leaf is a maximum of three and often just 1 or two. Read more…

Phytoliths, metals and phytoremediation.

Phytoliths, metals and phytoremediation.

by Chris ~ 17 November, 2011 ~ 3 comments

Plants take up essential nutrients (nitrates, phosphates, potassium, magnesium etc) through their roots, but some also take up other, more unusual substances – such as silicon, nickel, cadmium, copper, cobalt.

Grasses, in particular, are known to take up silicon and then deposit it in their leaves.  The silicon that they absorb is converted into tiny granules called phytoliths, which are often located under the waxy cuticle.   Read more…

Horse Chestnut leaf miner moth - an App

Horse Chestnut leaf miner moth – an App

by Chris ~ 12 September, 2011 ~ 4 comments

Many people have been following the various blogs (and contributing comments) on the problems that Horse Chestnut trees have faced over these last few years.  These problems include :-

  • bleeding canker
  • leaf blotch fungus
  • leaf miner moth

The horse chestnut leaf miner moth, which originated in the Balkans, first appeared here in 2002/3 in the South East, but it has since rapidly spread to many areas of the U.K. Read more…

Invasive species – Rats.

Invasive species – Rats.

by Chris ~ 8 September, 2011 ~ 2 comments

Rats (brown and black) have been ‘camp followers’ of humans ever since we adopted a ‘settled’ existence.  In modern cities, it is often said that one is never more than 20 yards from a rat.  Whether this is true or not, rats have been a pest throughout the millennia, most notably associated with the spread of disease such a bubonic plague but also Weils Disease (Leptospirosis). Read more…

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