Occurrence of benzotriazoles in the rivers Main,Hengstbach, and Hegbach (Germany)

Background, aim, and scope  

Benzotriazoles (BT) as 1H-benzotriazole (1H-BT), 5-methyl-1H-benzotriazole (5Me-BT), and 4-methyl-1H-benzotriazole (4Me-BT) are frequently used as corrosion inhibitors in dish washer detergents, aircraft de-icing/anti-icing fluids (ADAF), automotive antifreeze formulations, brake fluids, fluids for industrial cooling systems, metal-cutting fluids, and in solid cooling lubricants. Discharge of treated municipal waste water and controlled over-runs of combined waste water sewers are potential point sources for BT in rivers. The aim of this monitoring study was to yield an overview on exposure concentrations and loads of BT in the German rivers Main, Hengstbach, and Hegbach.     

Inheritance of dominance in honeybees (Apis mellifera capensis Esch.)

Summary Hierarchies in worker dominance are well developed in reproductive workers of the Cape honeybee (Apis mellifera capensis Esch.). Elements that influence worker dominance (trophallactic behaviour, fecundity, queen substance content) are mainly genetically determined. The estimated values for the heritabilities in the broader sense range from 0.27 to 0.89. This genetically based hierarchy leads to new insight into the theory of natural selection in honeybees. Besides selection at the colony level, or selection at the level of reproductives, natural selection also operates at the level of the individual worker bee within a colony.