Gannenlaus und Gannensterben

Zusammenfassung Die Weisztannenlaus Dreyfusia nüsslini C. B. bedroht in zunehmendem Masze unseren gesamten Tannenjungwuchs und bringt ihn unter bestimmten Bedingungen zum Absterben. Die Form dieses Sterbens ist bon der im allgemeinen beschriebenen Form bes Tannensterbens berschieden.Wenn bisher bei ber Bekämpfung bon nüsslini keine eindeutigen Erfolge erzielt wurden, so lag das vor allem daran, dasz der Bekämpfungszitpunkt nicht richtig gewählt wurde.Alls neuer Befämpfungszeitpunkt wird nicht mehr das Frühiahr, wo auf den empfindlichen Maitrieben verschiedene Formen der einzelnen Generationen vorhanden sind, gewählt, sondern eine bestimmte Zeit im Herbft (im Bsälzer und Frankenwald (September und auch nach ein Teil des Dktober), wa lediglich die Neosistensform vorhanden ist, gegen die das Kontaftstäubemittel Detal wirksam zum Einsatz kam.Es wird noch näher ausgeführt, dasz nur unter bestimmten Berhältnissen eine chemische Befämpfung in Frage kommt.Zur Eindämmung und Niederhaltung von nüsslini sind auszer einer chemischen Bekämpfung noch bestimmte waldbauliche Masznahmen erforderlich.     

Eine neue Tannenlaus (Dreyfusia prelli nov. spec.)

Ohne Zusammenfassung     

Zur makroskopischen Unterscheidung der beiden WeißtannenläuseDreyfusia nüsslini C. B. (nordmannianae Eckst.) undDreyfusia piceae Ratz.

Ohne Zusammenfassung Mit 3 Abbildungen.     

Q fever antibody titer--follow-up study in cattle with special reference to pregnancy]

In 290 Q fever positive cattle from three 2000 head dairy farms in the former district of Erfurt (Thüringen) the course of titers was examined serologically over several months by means of the complement fixation test (CFT). In 47.2% of the cows serologically observed for 2 up to 28 months complement fixing antibodies against Coxiella burnetii could be demonstrated til the end of the investigation period. Repeated tests during pregnancy showed increase of antibody titers in the first 4 months and after a short decrease again from the 5. til the 7. month. By observing the antibody titers during several pregnancies each time a new increase comparable to a booster immunisation could be found. This may explain the persistence of Q fever antibodies in cows for several years. The results of this investigation suggest that from a high antibody titer it can not be concluded an abortion in a positive cow being caused by a Coxiella burnetii infection.     

The Effect of Pasture Nitrate Concentration and Concentrate Intake after Turnout on Embryo Growth and Viability in the Lactating Dairy Cow

This study investigated the effects on embryo growth and survival rate of feeding heavily‐fertilised spring grass, containing high levels of quickly‐degradable nitrogen, to pregnant cows. Forty‐eight lactating Holstein cows between 2 and 8 weeks pregnant were turned‐out, after a one‐week transition period onto high‐ or low‐nitrate pasture and fed a high‐ or low‐concentrate supplement. Cows grazing the High nitrate pasture had significantly higher milk and plasma urea concentrations than cows grazing the Control pasture, while cows which were fed less concentrate had a notably higher plasma ammonia. However, there was no evidence that an increased quickly‐degradable nitrogen (QDN) intake from pasture affected embryo survival or growth from 20 days onwards. This suggests that the impact of turnout on fertility mainly affects ovulation, fertilisation and/or the early embryo.     

Basal and bile salt-stimulated bile flow and biliary lipid excretion in ponies

The role of bile salt in biliary lipid excretion was studied in 3 healthy ponies with chronic external biliary fistulas. After endogenous bile salt pool depletion, micelle-forming taurocholate or taurochenodeoxycholate was infused to replace excreted bile salt. Enterohepatic circulations were held open (total biliary diversion) throughout each study. Results indicated that biliary lipid excretion in ponies (113 +/- 21 nmol/min/kg of body weight) is approximately 10 times less than that reported in rodents. Although the lipid composition (4.4% cholesterol, 5.6% phospholipid, and 90% bile salt) was within the predicted range for a single phase of micellar (or vesicular) liquid in solution, it was supersaturated with cholesterol because of low absolute concentrations of bile salt and phospholipid. Ponies, like guinea pigs, were determined to have a high bile salt-independent secretion of biliary lipid with little (or no) coupling to endogenous bile salt output. However, bile salt excretion induced by higher taurocholate infusion rates (ie, those greater than the physiologic range of 61 to 125 nmol/min/kg) was positively correlated with an increase in biliary phospholipid excretion, but not cholesterol excretion, thus indicating that a threshold intracellular bile salt concentration may be associated with enhanced biliary phospholipid excretion in ponies. The apparent cholerectic effects of endogenous bile salts, taurocholate, and taurochenodeoxycholate (that is, the increment in bile flow per increment in bile salt recovered) were greater in ponies than reported for any other mammal.     

Seasonal changes in abundance and age structure of burbot Lota lota (L.) and stone loach Barbatula barbatula (L.) in the littoral zone of a large pre-alpine lake

Abstract – Seasonal changes in the abundance and age structure of the stone loach and burbot populations in the littoral of Lake Constance, Germany were examined. The abundance of both species was lowest during the summer months and highest during autumn. The stone loach population in the littoral comprised age classes 1 to 3 plus, in autumn, age class 0. The burbot population showed distinct seasonal changes in both length and age composition. During spring and summer, only age class 1 was present in the littoral whereas, in autumn, only age class 0 was caught. This remarkably strict habitat segregation of two age classes by season is discussed with respect to a possible mechanism for avoiding conspecific predator risk in a cannibalistic species.     

A Review of Methods Used in the Laboratory Diagnosis of Fireblight1)

Most well–known laboratory methods which can be used in the diagnosis of fireblight, as well as more recent developments in identification, have been discussed. They vary from the use of simple culture media to the use of immunofluorescent microscopy. The use of any one method alone is not advised, but by combining methods, accurate and rapid diagnosis is possible. In order to minimize diagnostic errors, especially among less experienced workers, the use of 5 % sucrose–nutrient agar for bacterial isolation followed by serological control is recommended. For further information reference is given particularly to the procedures described by Lelliott at the first EPPO Conference on Fireblight held in 1967 at Canterbury.