The obscure occurrence of the cottony-cushion scale Icerya purchasi Maskell in its native country Australia is generally attributed to its natural enemies. Twelve natural-enemy-exclusion experiments were conducted at monthly intervals to confirm the role of natural enemies. Each experiment had uncaged, open-caged, and caged treatments. The natural enemies were active throughout the year. The percentage of scales surviving to adults in the cages was significantly higher than in the open-caged treatments, except the April (first) cohort. In both open-caged and uncaged treatments, the percentage of scales surviving to adults was similar and matched the changes in the numbers of natural enemies, thus confirming their importance in controlling L purchasi in South Australia.

The electrochemical and chemical polymerization of acrylamide (AA) has been studied. The electrolysis of the monomer in N,N‐dimethylformamide (DMF) containing (C4H9)4NClO4 as the supporting electrolyte leads to polymer formation in both anode and cathode compartments. The cathodic polymer dissolves in the reaction mixture and the anodic polymer precipitates during the course of polymerization. A plausible mechanism for the anodic and cathodic initiation reaction has been given. The chemical polymerization of acrylamide that has been initiated by HClO4 is analogous to its anodic polymerization. The polymer yield increases with an increase in concentration of the monomer and HClO4. Raising the reaction temperature also enhances the polymerization rate. The overall apparent activation energy of the polymerization was determined to be ca. 19 kcal/mole. The copolymerization of acrylamide was carried out with methyl methacrylate (MMA) in a solution of HClO4 in DMF. The reactivity ratios are r1 (AA) = 0.25 and r2 = 2.50. The polymerization with HClO4 appears to be by a free radical mechanism. When the polymerization of acrylamide is carried out with HClO4 in H2O, a crosslinked water‐insoluble gel formation takes place.

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The electrolysis of acrylamide in sodium nitrate/N,N-dimethylformamide solutions leads to polymer formations simultaneously in the anode and cathode compartments. The influences of monomer concentrations. current levels, nature of some electrode metals and supporting electrolytes on polymerization were examined. Anodic polymers of high molecular weights were obtained (ca. 10'). The current-voltage curves and other experimental findings strongly suggest that the direct reduction of acrylamide at the cathode leads to the cathodic polymerization which is like the polymerization by anionic initiators in which the monomer gives a polymer of amide structure via a hydrogen transfer process. On the other hand, the anodic polymerization is possibly initiated by the species produced by the anodic reaction of the supporting electrolyte and is analogous to the free-radical polymerization of acrylamide. Infrared spectra of the polymers show that the cathodic polymer IS a polyamide (...-CH2-CH2-CO-NH-...) whereas the anodic has a C-C chain structure (...-CH2-CH(CONH2)-...).

Eating raw or insufficiently cooked mollusks is a known risk factor for human echinostomiasis. We confirmed identification of Artyfechinostomum sufrartyfex trematodes as the causative agent of disease among 170 children in northern Bihar, India. We also identified the snail Pila globosa as a potential source of infections in the study area.