A survey of sheep dip usage in Scotland in 1978

A survey of sheep dipping in Scotland in 1978 showed that about 42 tonnes of organophosphorus and 17 tonnes of organochlorine insecticides were used to control ectoparasites. Information is presented about their pattern of use and about the disposal of surplus sheep dip and the empty containers. Six river pollution incidents involving sheep dips in 1978 are recorded. The main geographical areas affected by headfly (Hydrotaea irritans Fall.) and the measures taken against them are noted.     

Determination of bromide ion content of cereals and other foodstuffs by specific ion electrode

A method is presented which determines the bromide ion content of foodstuffs using a bromide specific ion electrode. For low levels of bromide (< 10 mg/kg) or for accurate work, bromide was extracted from the ground commodity with water and then separated from interfering compounds by ion-exchange chromatography before estimation. Alternatively, bromide ion can be estimated approximately by direct measurement on the aqueous extracts after heating to denature proteins. The method was checked against three standard methods of bromide estimation in foods, using wheat that had been repeatedly fumigated with methyl bromide. The equipment required is inexpensive and can be adapted for field use. The method has been used to determine the bromide and chloride contents that occur naturally in wheat, maize, copra, soya beans and sorghum.     

Pesticide usage on bananas with special references to fungicides

Bananas (including plantains) are widely grown throughout the tropics both for local consumption and for export. Pesticide usage is confined largely to the export crop because of its value and the susceptibility to diseases of varieties suitable for the export market. Most of the bananas grown for export are produced in Latin America and the Caribbean. Weed control with herbicides is particularly valuable in young banana plantations before a mature canopy is produced and when weeds compete with the shallow rooting system. Insecticides are used to control high populations of the banana weevil and may be used against fruit thrips. Nematicides are used extensively to control the banana root nematode and granular applications are now replacing soil injections. Fungicidal control of Sigatoka leaf diseases and fruit diseases has been practised for many years and is essential for the production of high quality, exportgrade fruit. Changes in the chemicals used and in application techniques have brought important benefits in recent years and genetic resistance is likely to play a large part in disease control in the future.     

Etiology of patent ductus arteriosus in dogs

Patent ductus arteriosus (PDA) is the most common congenital heart disease in dogs and usually causes heart failure and death unless corrected at a young age. Previous histologic studies in a line of dogs derived from Miniature Poodles with hereditary PDA identified varying degrees of hypoplasia and asymmetry of ductus-specific smooth muscle and the presence of aortalike elastic tissue in the ductus wall sufficient to cause patency. To determine if similar structural abnormalities cause PDA in other dogs, serial-section, 3-dimensional histology of ductal architecture was studied in 8 non-Poodle purebred dogs with PDA with no immediate family history of PDA. Morphologic abnormalities were observed in 7 of 8 dogs with PDA and essentially were the same as those in dogs known to have a hereditary form of PDA. These findings suggest that apparently sporadic PDA in these breeds is caused by a genetic defect in the structure of the ductus arteriosus that is similar or identical to that in the Poodle. The relatives of dogs with PDA, particularly parents, offspring, and siblings, should be screened for evidence of PDA. Dogs with PDA should not be used for breeding, regardless of breed.     

Adjuvants in veterinary vaccines: modes of action and adverse effects

Vaccine adjuvants are chemicals, microbial components, or mammalian proteins that enhance the immune response to vaccine antigens. Interest in reducing vaccine-related adverse effects and inducing specific types of immunity has led to the development of numerous new adjuvants. Adjuvants in development or in experimental and commercial vaccines include aluminum salts (alum), oil emulsions, saponins, immune-stimulating complexes (ISCOMs), liposomes, microparticles, nonionic block copolymers, derivatized polysaccharides, cytokines, and a wide variety of bacterial derivatives. The mechanisms of action of these diverse compounds vary, as does their induction of cell-mediated and antibody responses. Factors influencing the selection of an adjuvant include animal species, specific pathogen, vaccine antigen, route of immunization, and type of immunity needed.     

Insect chemical ecology research in the United States Department of Agriculture-Agricultural Research Service

This multi-author paper reviews current work by USDA-ARS scientists in the field of chemical ecology. Work with pheromones, the discovery and development of the codling moth kairomone, studies on insect-plant interactions and chemically mediated tritrophic plant-insect interactions have led to practical methods for control of important insect pests.     

Toxicity of cyanogen to insects of stored grain

Range-finding studies on the toxicity of cyanogen to all stages of five species of stored product Coleoptera are reported. The species were Rhyzopertha dominica (F), Sitophilus granarius (L), Sitophilus Oryzae (L), Tribolium castaneum (Herbst), Tribolium confusum Jacquelin du Val and Ephestia cautella (Walker). Exposures for 24 h to cyanogen at 1.3 mg litre(-1) controlled all external stages. Control of internal stages of Sitophilus species was achieved by a 5-day exposure to initial concentrations between 13.7 and 27.4 mg litre(-1), whereas R. dominica was controlled at 13.7 mg litre(-1). Cyanogen showed similar toxicity to all tested external stages and, in this respect, was more similar to methyl bromide than to phosphine. Its toxicity to insects increased with both relative humidity and concentration of carbon dioxide. Cyanogen was toxic to insects whether applied as a gas or in an aqueous solution.