Serologic responses of pregnant thoroughbred mares to vaccination with an inactivated equine herpesvirus 1 vaccine

The immunogenic potency and safety of a chemically inactivated equine herpesvirus 1 vaccine with added adjuvant was evaluated by testing serum-neutralizing and complement-fixation antibody responses of pregnant Thoroughbred mares. The vaccinated population comprised 321 pregnant mares on 7 farms; 3 in Normandy, France; 1 in Kildare, Ireland; and 3 in central Kentucky. The pattern of antibody response to vaccination was found qualitatively and quantitatively similar to that of pregnant mares previously vaccinated and determined by challenge exposure to be immune to abortigenic infection under experimentally controlled conditions. The safety of the vaccine was demonstrated by the occurrence of only 2 local untoward reactions to the administration of 941 IM injections.     

Effect of canopy cover,seeding depth,and soil moisture on emergence of Centaurea maculosa and C. diffusa*

The effects of canopy cover, seeding depth, and soil moisture on emergence of Centaurea maculosa Lam. and C. diffusa Lam. were studied. Canopy cover had no effect on ermergence rate (seedlings/day/100 seeds) of either species. Seeds of both species emerged faster when placed on the soil surface. Emergence rate decreased as seeding depth increased. Both species required more than 55% initial soil moisture to initiate emergence, with 65–70% being optimum. Percentage emergence followed exactly the same trend as emergence rate. C. maculosa had better emergence characteristics over a wider range of conditions than C. diffusa, possibly being some of the reasons for the former having a wider geographical distribution in the United States and Canada.     

Britain's Pest Monitoring Network for Aphids and Moths1

There is a need for continuous monitoring of insect populations to provide, in the short term, early warning of the presence of pests and, in the long term, to record and analyse faunal changes resulting from changes in agricultural practice and urbanisation, and the rate of spread of pests and resistance to pesticides. The Rothamsted Insect Survey examines aerial populations of two major insect groups throughout the year. Two hundred and sixty species of aphids are sampled daily at a height of 12 m by a grid of 21 suction traps. Early warning of the migration of 32 aphid species of economic importance is provided in weekly bulletins issued to farmers and advisers. This aerial sampling is generally cheaper, quicker and provides earlier warning of the presence of aphids than crop sampling. Six hundred species of moths are sampled by 195 light traps and the data are being used to assess the magnitude and reasons for seasonal, annual and long-term changes in the insect fauna, especially of pest species. The information on both insect groups is stored on magnetic tape and computerized maps are produced to illustrate the distribution in time and space of given species and as a research tool in studies on their population dynamics. The prospects and value of extending this system to continental Europe, and the help and expertise that Rothamsted could give in the eventuality, are outlined. Les populations dinsectes doivent dtre soumises à un recensement continu afin dassurer, à court terme, un avertissement précoce de la presence des ravageurs, et, à long terme, la possibilite d'enregistrer et d'analyser les changements qui interviennent dans la faune à la suite de I'evolution des pratiques agricoles et de I'urbanisation, et de déterminer la vitesse de dissémination des ravageurs ainsi que leur résitance aux pesticides. Le «Rothamsted Insect Survey » observe les populations de deux groupes d'insectes durant toute L'année. Deux cents soixante espèces de pucerons sont échantillonnées quotidiennement dans 21 localites differentes à L'aide de pièges à succion disposes a 12 m au-dessus du sol. Les exploitants et les conseillers sont avertis, par des bulletins hebdomadaires, des migrations de 32 espèces de pucerons d'importance économique. L'échantillonnage aérien semble être meilleur marché et plus rapide qu'un échantillonnage réalisé au niveau de la culture;de plus, il assure un avertissement plus précoce. Six cents espèces de lépidoptéres sont recensées au moyen de 195 piéges lumineux dans le dessein danalyser la magnitude et les causes des variations saisonnieres, annuelles, et à long terme surtout en ce qui concerne les ravageurs. Les données ainsi recueillies sont enregistrées sur bandes magnétiques et servent à L'etablissement de cartes à L'aide d'ordinateurs; ces cartes indiquent la distribution temporelle et spatiale de chaque espèce et constituent un élement important dans l'étude de la dynamique des populations. L'extension de ce réseau à L'Europe continentale présente deL'intérêt et la façon dont la Station de Rothamsted peut y apporter son soutien est exposée dans la présente communication.