Saturday, 20 July 2013

Another Pocket Park Miscellany

Loose smut Ustilago nuda on barley.
Byfield, 20.July, 2003
I took a trip to the Byfield Pocket Park today - my first visit for a fortnight or so. I approached via the margins of a field, where a barley crop was looking very well. A few of the ears were affected by Loose Smut, Ustilago nuda. This is an easily controlled fungus problem in Britain but in Northern India, where farmers lack the resources for its control, it can be devastating, wiping out whole crops. Fungal infections such as this are very widespread. A little further on a huge branch from a poplar had fallen, blocking the footpath. It gave me an excellent opportunity to examine the foliage and I found that many of the leaf blades had quite large, upward bulges on the upper surface, while the lower surface had the matching concavity covered with a crust of bright yellow fungus. This was Taphrina populina, a common and widespread organism which appears to cause little or no harm to the tree.

Poplar leaf with Taphrina populina
Byfield Pocket Park. 20 July, 2013
Poplar leaf (lower surface) with Taphrina populi.
Byfield Pocket Park.  20 July, 2013
Ragwort, Senecio jacobaea.
Byfield, 20 July, 2013

Nearby was a robust Ragwort plant. This species has, understandably, received a great deal of adverse publicity over recent years on account of deaths to livestock. Horses are particularly susceptible but tests suggest that a healthy horse would need to eat a quantity of Ragwort equivalent to 7% of its body weight for a lethal dose! From an entomological point of view it is excellent, attracting a considerable range of insects. Today I noted three species of hoverfly calling in for refuelling with nectar and pollen.

A little further along the same hedgerow Hogweed Bonking Beetles, were involved in the activity which has given them their semi-official name. The species, Rhagonycha fulva, is one of the soldier beetles, and it uses the broad umbels of hogweed as a trysting place. Its amorous activities have led to its status as one of Britain's commonest beetles. The dark tips to its hard outer wings (the elytra) make it easily recognisable.

Rhagonycha fulva mating on the umbels of Hogweed.
Byfield, 20 July, 2013

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