Rearing non-diapausing western spruce budworm on pre-mixed artificial diet

The western spruce budworm, Choristoneura occidentalis Freeman, was reared on pre-mixed artificial diet in the laboratory without diapause. The colony was maintained indefinitely with a generation time of 38 to 40 days. Females deposited an average of 307 eggs of which about 91% survived. The rearing technique provided a steady and reliable supply of the insects for other basic research. The supply of insects could be adjusted according to need at any particular time.Sanitation is essential to successful rearing, because contamination of dict or rearing facilities produces an unsuitable environment for the survival and development of newly-hatched larvae

How Human Brucellosis Incidence in Urban Kampala Can Be Reduced Most Efficiently? A Stochastic Risk Assessment of Informally-Marketed Milk

In Kampala, Uganda, studies have shown a significant incidence of human brucellosis. A stochastic risk assessment involving two field surveys (cattle farms and milk shops) and a medical record survey was conducted to assess the risk of human brucellosis infection through consumption of informally marketed raw milk potentially infected with Brucella abortus in Kampala and to identify the best control options.In the cattle farm survey, sera of 425 cows in 177 herds in the Kampala economic zone were sampled and tested for brucellosis using a competitive enzyme-linked immunosorbent assay (CELISA). Farmers were interviewed for dairy information. In the milk shop surveys, 135 milk sellers in the urban areas were interviewed and 117 milk samples were collected and tested using an indirect enzyme-linked immunosorbent assay (IELISA). A medical record survey was conducted in Mulago National Referral Hospital for serological test results. A risk model was developed synthesizing data from these three surveys. Possible control options were prepared based on the model and the reduction of risk was simulated for each scenario. Overall, 12.6% (6.8-18.9: 90%CI) of informally marketed milk in urban Kampala was contaminated with B.abortus at purchase and the annual incidence rate was estimated to be 5.8 (90% CI: 5.3-6.2) per 10,000 people. The best control option would be the construction of a milk boiling centre either in Mbarara, the largest source of milk, or in peri-urban Kampala and to ensure that milk traders always sell milk to the boiling centre; 90% success in enforcing these two options would reduce risk by 47.4% (21.6-70.1: 90%CI) and 82.0% (71.0-89.0: 90%CI), respectively.This study quantifies the risk of human brucellosis infection through informally marketed milk and estimates the incidence rate in Kampala for the first time; risk-based mitigation strategies are outlined to assist in developing policy

Permeability of the insect cuticle to water and the transition phenomenon

The epicuticular wax layer prevents excessive loss of body water in most insects. The innermost layer of the wax is an oriented monolayer, offering the greatest resistance to the movement of water molecules across the cuticle. Several workers have shown that this oriented monolayer undergoes phase transition at a certain temperature and that the loss of water increases rapidly above this temperature which is now known as transition temperature. Other researchers deny a sharply defined transition point and claim that loss of water increases exponentially with temperature. The controversy includes Corixids. This work was carried out in an attempt to study the water relations of Cenocorixa expleta (Hungerford) in dry air. An apparatus was built to pass dry air over a single insect at constant speed and temperature. Measurements were made of the evaporation rate and the temperature of the cuticle, using copper-constantan thermo-couples made from 47 s.w.g. wires. In one series of experiments, the insects were pre-treated by immersion in water or surfactant solutions of various temperatures before their evaporation rates were measured in dry air of 20 G. Adult C. expleta have a transition point which lies near 30 C but composite evaporation/temperature curves do not show it. The evaporation rates in dry air are slightly temperature-dependent below, and highly temperature-dependent above transition. When caused by high temperature air, transition appears to be reversible: the insects regain waterproofness at approximately 25 C. To prove or disprove the existence of a transition point it is necessary to measure the evaporation rates of an individual insect over the entire temperature range. Phase transition and loss of waterproofness can also be caused by water of 30 C to 35 C. In this case the effect is irreversible. Detergent solutions of sub-transition temperatures remove a small fraction of waterproofing agent, possibly the non-oriented portion of the wax layer. The presence of the transition phenomenon in G. expleta, i. e., the fact that these insects lose their waterproofing, suddenly at approximately 30 G, and the fact that they lose this waterproofing permanently if it is caused by high temperature water, may limit their successful survival in small water bodies and thus their distribution.Land and Food Systems, Faculty ofGraduat

Rearing non-diapausing western spruce budworm on pre-mixed artificial diet

The western spruce budworm, C. occidentalis Freeman, was reared on pre-mixed artificial diet in the laboratory without diapause. The colony was maintained indefinitely with a generation time of 38-40 days. Females deposited an average of 307 eggs of which about 91% survived. The rearing technique provided a steady and reliable supply of the insects for other basic research. The supply of insects could be adjusted according to need at any particular time. Sanitation is essential to successful rearing, because contamination of diet or rearing facilities produces an unsuitable environment for the survival and development of newly-hatched larvae

Toxicity and relative selectivity of acephate to target and non-target organisms

Aspects of toxicity and activity of acephate were studied in non-diapausing, laboratory-bred larvae of Choristoneura occidentalis Freeman, larvae of Anagasta kuehneilla (Zeller), and in male Wistar rats. Inhibition of human erythrocyte acetylcholinesterase (AChE) in vitro was also investigated. Topically applied acephate was twice as toxic to last-instar larvae of C. occidentalis as to last-instar larvae of A. kuehniella. However, it was less toxic to C. occidentalis larvae than methamidophos or paraxon. These results were supported by a series of in-vitro experiments in which anti-AChE activity decreased in the order: paraoxon methamidophos acephate. There was indication that acephate per se inhibits AChE in vitro in proportion to its toxicity in vivo

Toxicity and metabolism of acephate in adult and larval insects

Adult and larval insects from the terrestrial and aquatic environments were exposed to acephate. The chemical was more toxic to adult insects than to larvae, and was a poor insect cholinesterase inhibitor in vitro compared to methamidophos which was a much stronger inhibitor. Both acephate and methamidophos inhibited the adult cholinesterase in vitro much more strongly than they did the larval enzymes. Acephate was metabolized by the insects to methamidophos which did not appear to be the only metabolite, although no other metabolites were looked for. The cholinesterase of insects exposed to sublethal levels of acephate was inhibited, but this inhibition appeared to be due to the combined effect of acephate and methamidophos and not to any hypothetical substance with greater anticholinesterase activity. This was bourne out when acephate was incubated with mixed function oxidases (MFO). No activated product with potent anticholinesterase activity was identified. Methamidophos was not produced by the MFO system but by some other unidentified mechanism

Genetische Grundlagen der Kaesereitauglichkeit von Rohmilch

Available from TIB Hannover: DW 5791 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman