Techniques for the Assessment of Growth of Micro-organisms on Plumbing Materials Used in Contact with Potable Water Supplies

Water samples from plumbing installations have often been of poorer microbiological quality than samples collected from the distribution main. This deterioration is often associated with a musty taste or visible turbidity in the water and slimes have sometimes been observed on water fittings. A technique to assess the ability of plumbing materials to support microbial growth is described and the most common categories of materials capable of supporting growth are identified. The most significant micro-organisms frequently found to grow on unsuitable materials were coliform organisms, especially members of the genus Citrobacter. Aeromonas hydrophila, Pseudomonas aeruginosa and fungi.     

Identification of Planococcus citri (Homoptera: Pseudococcidae) and the description of a new species

Planococcus pacificus sp.n. is described from the South Pacific, Australia and South East Asia. P.citricus is synonymized with P.citri. A key and illustrations are given to separate the species discussed from each other and from the similar P.ficus group.