An 8-month-old Sydney Silky dog that was ataxic and hyperkinetic was found to have a neurovisceral storage disease. Typical Gaucher cells were seen in the liver, lymph nodes and cerebellum, but not in the spleen. Ultrastructurally, the storage bodies in Gaucher cells contained tubular structures, and many neurones contained laminated cytosomes. accumulations of a ‘wispy’ material and rarely tubular material. Chemically, the liver and brain contained glucocerebroside.

The disease, tropical theileriosis, caused by the protozoan parasite Theilerla annulata is assuming greater importance in many tropical and sub-tropical countries because of the improvement in the breeds and productivity of cattle in these countries. Methods of control of the disease are inadequate and a suitable means of immunization would be of great value to the respective livestock industries. The literature dealing with these aspects of the disease relevant to its importance and methods of control is reviewed. Methods of immunization are considered and work is described on the isolation, cultivation, attenuation and use of strains of the parasite. Special attention is paid to the medium used for growing the infected lymphoid cells and the factors contributing to optimum, satisfactory growth. The research described is concentrated on the preparation of vaccines attenuated in tissue culture. Details of the methods of adaptation to and attenuation in, tissue culture of strains of T.annulata. and experiments leading to the development, preservation and use of a definitive vaccine are described, The initial assessment of possible vaccinal value is based on the clinical and haematological response of susceptible bovine animals and the definitive vaccine used is an attenuated strain, initially isolated in Iran. This strain is investigated in respect of its safety in use, its properties as a field vaccine, its ability to withstand deep frozen storage and its immunogenic characteristics. It is shown that the vaccine can "be stored at -70°C. very satisfactorily using glycerol or dimethyl sulphoxide as cryoprotectants, that it is effective when administered subcutaneously and that it causes a readily detectable reaction in susceptible cattle, producing schizonts but not erythrocytic forms; and that' it engenders immunity to a heterologous strain of the parasite. Experiments are described in which an immunity is shown to be produced in cattle which is strong at 1+ months when challenged by a local heterologous strain and still exists, but at a lower level, 12 months after vaccination. Attenuation of T.annulata strains in tissue culture is discussed and a regimen for vaccination of calves and particular care that should be taken for vaccination of adult cattle are suggested. Some suggestions far future investigations are made.

Lettuce has been the most important winter vegetable crop in the Imperial Valley for the past four years, averaging about 42,000 acres grown, and an average gross value of about $35 million. Lettuce grown for harvest in midwinter (December 15 to March 15) is planted from about September 10 to November 5. Plantings during October are largely of the cultivar Climax. During the winter harvest season of 1968–69, a disorder, later known an internal rib necrosis (IRN), occurred throughout the Imperial Valley in epidemic proportions just prior to harvest and caused serious losses in the field and in transit. Persons associated with the lettuce industry recalled the disease from past years but it had never been ranked as a major disease until 1969. No valid estimate was made of the losses from internal rib necrosis during the 1968–69 season but it was common for growers to abandon entire fields. Since then IRN has appeared sporadically in lettuce planted for midwinter harvest but not in epidemic proportions. In addition, a postharvest disorder (then called rusty rib) now called rusty brown discoloration (RBD), occurred on lettuce during storage and transit at 35°F. In February 1969, 90% of the lettuce shipments arriving in New York had RBD. The cause (or causes) of IRN and RBD has not been identified but environmental conditions (freezing temperature and rainfall), aqua ammonia damage and a synergistic reaction between beet western yellows virus and lettuce mosaic virus have been speculated as causes. Two papers presented here report the results of cooperative research by personnel of the California Agricultural Experiment Station, the California Agricultural Extension Service, and the US Department of Agricultural to determine the causes of IRN and RBD.

The dried fruit beetle, Carpophilus hemipterus (L.) (Coleoptera : Nitidulidae), is one of the most serious stored products’ pests and destroys fruit in almost every country. Fruit such as apples, apricots, bananas, plums, peaches, oranges and grapefruit; cereals; dried fruit; seeds and other stored products have been reported to be subject to the beetle attack (Hinton, 1954 and Munro, 1966). In New Zealand, attack by C. Hemipterus is of minor importance when compared with overseas countries, especially U.S.A. Some N.Z. infestations have been serious enough to be recorded, such as the infestation of dried fruit in Christchurch during 1922 (Miller, 1922) and of prunes in storage in Dunedin during 1949 (Belton, 1950). The damage is generally caused by feeding injuries and always followed by rots which increase the damage and allow it to reach injurious levels. Various micro-organisms that are responsible for rot disease such as fungi of different genera, yeasts and bacteria have been observed to be transmitted by C. hemipterus. According to Leach (1940), the association of C. Hemipterus and rot diseases is considered to be of the non-obligatory type, since the association is not restricted to any particular type of host organism. Therefore, the spread of rot disease is very significant when this dried fruit beetle is involved. Dissemination of the disease is carried out by mechanical means through wounds made by beetles (Phillips et al, 1925) and/or by the beetles bringing the rot organisms into contact with natural openings of plants. When the mechanism of bacterial transmission on by insects is considered, there are three factors that must be considered as governing the transmitting process. These are: (a) External and/or internal contamination of the insect’s body. Insects capable of being both externally and internally contaminated are more efficient as disease carriers than those capable of being contaminated only externally, Multiplication of bacteria in internal parts such as the digestive system and faecal material are the most important factors that allow bacteria to be continuously generated and beetles to be most suitable vectors. (b) Duration of viability of bacteria on or in the insect's body. The duration of bacterial viability when the bacterium is on or in the insect's body is very important since the vector's body offers different microclimatic environments from normal natural conditions. (c) The category of the vector. The question arises as to whether or not the insect is a true non-obligatory vector which possess no restriction in carrying any phytopathogenic organisms, This is because past observations showed that there was a possibility of the beetle transmitting fungal and yeast rot, as well as bacterial rot, From the knowledge of bacterial association with vectors (see literature review, Chapter II), the conclusion can be reached that there are possibilities of C. hemipterus transmitting bacterial rot diseases under New Zealand conditions. Since there is lack of knowledge in the field of bacterial transmission, the aim of the present study was, in general, to prove the possibilities of transmission by C. Hemipterus of bacterial pathogens. This was considered to be best done specifically by examining the three important factors mentioned above and to investigate; (1) Contamination of the beetle by bacteria. (2) Duration of viability of bacteria in or on the beetle. (3) The nature of the beetle as a vector,