The Beanly, Francis

Wasp Fly, Berners
Whitlock Vibert Box (WVB)  English
  A plastic container for stocking eyed eggs of trout. If a river is stocked with fry hatched in an artificial hatchery, the mortality rate is high. Additionally the purchase of fries requires considerable amounts of money. In order to solve this problem, methods were investigated by which eyed egg is buried into the grit of a river bottom to hatch in a natural river. In 1950, a method using a hatch box was successfully developed by Dr. Richard Vibert in France, who patented it. This Vibert box was manufactured by Pezon et Michelle company, and has spread to Europe and to the United States.
  In the United States, stocking of trout using the Vibert Box was initially undertaken by Trout Unlimited (TU), and thereafter by the Federation of Fly Fishers (FFF). After developing the proper use of the box the hatching rate with the Vibert box rose to 90%. It was used in various rivers, but it became clear that the box had some problems. Dave Whitlock and his colleagues improved upon the problems and created an advanced version called Whitlock Vibert box (WVB).
  WVB is a knock-down kit of plastic plates, white or black in color. Its assembled size is 145 x 90 x 60 mm. WVB has two chambers, 50 eyed eggs are put into the lower chamber (hatching room), and the upper chamber is a nursery room for fries. Usage of the WVB increased the hatching rate to as high as 95%.
eyed egg, Trout Unlimited, Federation of Fly Fishers, Dave Whitlock
Selected Headings

River Spey in the evening.
 The photo was taken when the author visited the river for the first time,
and it was the day before the fishing was started.
 At Grantown-On-Spey, Scotland.