The Golden Wing Prize 1993

ONE OF THE SPIDERS' SECRET MYSTERIES IS NOW SOLVED.

Many people have probably observed that spiders can move at lightning speed. But they can only run for 10-20 seconds before becoming exhausted. Researchers have naturally wondered about the cause of this behaviour. Most have leaned towards the theory that the hydraulic pressure drops in the fluid that replaces certain muscles in spiders' legs. The body fluid, which serves as the hydraulic fluid, would thus after a while seep from the legs into the body itself. After 10-20 seconds, the fluid pressure would have dropped so much that the spider could no longer move so fast.

The other theory as to why spiders have such limited stamina is based on their fuel, for example glucose, running out and the accumulation of lactic acid.

At the University of Florida, researcher Kenneth Prestwick thought it was time to find out which of the theories was correct. According to the journal New Scientist, Prestwick constructed catheters so small that they could be inserted into some spiders' legs. He then forced them to run for two minutes. After 20 seconds, the spiders had lost two-thirds of their starting speed but had covered half the total distance. Eventually they could no longer move. But the fluid pressure in the legs remained high for over a minute. The pressure drop theory, which had been considered the most likely, could thus be ruled out directly.

A true researcher does not give up until he has clear evidence of the cause of a behaviour. Prestwick therefore continued his investigations by measuring the lactic acid levels in his running spiders. But these did not rise until after a minute. Glucose levels did not drop after 20 seconds either. Prestwick had thus failed to prove which of the two theories was correct. Instead, he had proved that neither of them applied.

But shame on those who give up. Finally Prestwick succeeded in solving the spiders' secret. The spiders turned out to deplete their store of energy-rich phosphates such as adenosine triphosphate in approximately 20 seconds.

Gunnar Bakken

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GÄSTRIKLAND'S ENTOMOLOGICAL SOCIETY

THE GOLDEN WING PRIZE 1993

Gästrikland's Entomological Society has decided that, where reason exists, to award both a GOLDEN WING PRIZE and a SEXTON BEETLE PRIZE to those who in recent times have done something positive and negative respectively for Gästrikland's insect fauna.

For the society it has not been difficult to find a worthy recipient of this year's GOLDEN WING PRIZE. For more than 30 years, many of the society's members have enjoyed the fantastic fauna and flora in the power line corridor that runs just south of Trösken and where it passes both the infields in the southern part of Grinduga village and the magnificent Gustavmyren.

During 1993, we have found more than 70 individuals of Sweden's red-listed day-flying butterflies resident in Norrland within the power line corridor. The butterflies have been listed by the Database for Threatened Species. This Database, based in Uppsala, has the task of listing all of Sweden's threatened species, both plants and animals. The list has been established by the National Environmental Protection Agency. The species in this power line corridor are an excellent example of the "biological diversity" that so many talk about needing to preserve but which we regrettably seldom see concrete examples of.

The question one asks is how it is possible that all these butterflies and numerous rare plants such as Quaking-grass, Polystichum, Meadow and Field Gentian, to mention just a few, are found in this power line corridor? There are probably at least four contributing reasons for this.

1. The damp calcareous moraine, which provides the foundation for the majority of rare plants and animals.

2. The area and areas in its vicinity have since ancient times been prevented from becoming overgrown thanks to many natural causes such as grazing, flooding, forest fires etc. and human activity such as hay-cutting and grazing.

3. The area is today managed in an apparently exemplary manner with effective yet ecologically sensitive scrub clearance.

4. The area has been continuously managed in the same way over a long period, approximately 75 years, which has enabled the animals and plants now found in the area to adapt well to this very natural management and in some cases even to increase their populations.

The prize goes to Vattenfall, Central Region, which since this power line was built in 1916 has been responsible for hand-clearing the power line corridor. This more than 75-year continuous "management" of an area which, in addition to being sufficiently large and through its elongated form apparently very favourable for both fauna and flora, has not only preserved an exceptionally valuable area in Gästrikland but perhaps even given the region one of its most interesting areas from an entomological perspective. The continuous management over such a long period has made possible a unique development of the fine forest edge biotope which often harbours precisely the natural diversity that we so like to talk about but which we regrettably seldom see concrete examples of.