May bug – Cockchafers - Hanneton commune and Hanneton forestier in France.

Hardly extraordinary I can hear people thinking but the other day I saw a May bug here, first one in several years. In fact in the 25 years we have been here there have only been a couple of years when I have seen them.  

A May bug or Cockchafer generally refers to Melolontha melolontha or the Common Cockchafer but there is an almost identical species in France with which they could be confused which is the Forest cockchafer, Melolontha hippocastani, which is a species found in woodlands.  

Generally Melolontha melolontha is considered an to be  an agricultural pest and they were brought almost to the point of extinction in the arable areas of France following the use of chemical insecticides such as DDT and Lindane. Both of these caused massive environmental harm before being banned from use. In the 19^th century prior to insecticides being available the beetles were collected by hand to be killed, a process called “hannetonnages” that had some effectiveness even if a little laborious. Schoolchildren would sometimes be enlisted to perform this task where they would place sheets under the hedgerows in the morning and shake them out, collecting them in containers. Back at school the chafers would be weighed and some payment made by the kilo, a kilo roughly equalling 1,200 chafers. We can only dream of such numbers these days.

Since the 1970’s their numbers have slowly recovered on pasture land. However where intensive arable farming is practiced they are few and far between as almost every available piece of land is cultivated and constantly ploughed. This practice makes it close to impossible for them to complete their life cycle as any larvae, in the unlikely event that there should be any, are constantly bought to the surface and exposed to the birds that follow the tractors. This only leaves the roadside verges and any small uncultivated parcels of land. The situation has been made worse by the removal by the EU some 15 years or so ago of the requirement for farmers to leave a percentage of land fallow. This resulted from the misconceived idea that bio fuels are more important than habitat, a decision that has caused and is causing untold harm to a vast range of species.   

Chris

CHAFERS IN FRANCE

Beaver in Nord pas de Calais for the first time in 150 years

The presence of Beavers has been confirmed in the area around Val-Joly, in the Avesnois, Nord-Pas-de-Calais after 150 years of absence. More than 20 trees have been found with the distinctive pencil cutting and fur traps have provided DNA evidence.

The beavers will have crossed the border from Wallonie, (Belgium), where they were released in the early 2000’s by activists where they have apparently expanded at an extraordinary rate both in numbers and territory covered in the canals and rivers that crisscross the region.

Unlike the recent discovery in Pyrénées-Atlantiques which is likely to have been a clandestine release this will be a natural progression and should provide a basis for continued expansion throughout the region.

 Chris

Beaver in France Link

Freshwater jellyfish in France.

This summer we experienced a very long period of drought and two scorching heat waves which are probably the reason for an unusual and little known phenomenon to occur in the Vienne departement along with other parts of west and southwest France! These were exactly the right conditions when the water warms sufficiently for the emergence of a tiny freshwater jellyfish, craspedacusta sowerbii.  

They are normally only seen when they take the form of a small bell-shaped jellyfish known as a hydromedusa and float near the surface of the water but this requires a water temperature of at least 25°C and forms only one part of their interesting lifecycle.

As a jellyfish they are 20–25 mm in diameter, somewhat flatter than a hemisphere, and very delicate. They have a whorl of up to 400 tentacles tightly packed around the bell margin. Hanging down from the center of the inside of the bell is a large stomach structure called a manubrium, with a mouth-opening and four frilly lips. Food is taken in and waste  expelled through the mouth opening.

Click photo to enlarge

Craspedacusta sowerbyi more often exist as microscopic podocysts (dormant "resting bodies"), frustules (larvae produced asexually by budding), planulae (larvae produced sexually by the hydromedusae), or as sessile polyps, which attach to stable surfaces and can form colonies consisting of two to four individuals and measuring 5 to 8 mm.

This species, originally from China (Yangtze River Basin), probably originally arrived in Europe with aquatic plants imported for botanical gardens. In the ponds of Kew Gardens, near London, it was discovered in 1880 by the naturalist William Sowerby. Since then, it has conquered every continent thanks to the trade in aquarium plants.

In France they can be found in slow moving rivers, lakes and ponds, maybe even your garden pond if they have been transported there with pond plants or stuck to birds’ feet.  Should you come across them you need not worry, they present no danger to humans or other mammals.

Chris