Glückwunsch und Dank!

Ohne Zusammenfassung     

Zum Tode von Dr. Walter Bosshard

Ohne Zusammenfassung     

Bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae) as a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae) in Bulgaria

The major bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae), a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae), were studied from 1987 to 2003. Poplar shoots infested with P. tabaniformis larvae were collected in 11 localities in Bulgaria and examined in the laboratory, and infestations were also studied in the field. B. intercessor was recorded in seven localities and was found to be a gregarious external larval parasitoid of P. tabaniformis. Two generations of the parasitoid developed on the host. The first (summer) generation was associated with early and mid-stage (up to third instar) host larvae, and the second (overwintering) generation with third- to fifth-instar larvae. The average number of parasitoid individuals feeding on a host was 4.5 and 12.4 in summer and overwintering generations, respectively. The maximum number recorded was 25 individuals per host in the overwintering generation. B. intercessor overwintered as a mature larva on the host and completed its development in early spring. The adults from the overwintering generation appeared in April, about 1 month prior to emergence of P. tabaniformis. The life cycle of B. intercessor was not in close synchrony with the development of P. tabaniformis in the spring, but the parasitoid adults which fed on honey-sugar solution lived for up to 31 days (males) and 86 days (females), respectively. This suggests that, in the field, B. intercessor females eclosing in the spring could survive until the host larvae appear if nectar is available. Adults of the summer generation emerge from July to September when sufficient suitable host larvae are available. B. intercessor was responsible for 1.5% of the average mortality of the P. tabaniformis overwintering larvae. The host mortality caused by the summer generation of the parasitoid ranged from 3.2% to 5.8%.     

Parasitoids of Saperda populnea (L.) (Coleoptera: Cerambycidae) on aspen (Populus tremula L.) in Bulgaria

The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997?–?2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8?%) and D. populneus (29.4?%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7?%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8?%, and the highest mortality observed in individual study was 20.2?%.     

Development of the concept of the ecological functions of the soil cover and other geospheres

The concept of the ecological functions of soils and geospheres is discussed, and soil functions in biogeocenoses and in society-nature systems are analyzed. The major ecological functions of the interrelated surface spheres of the Earth are specified. Urgent problems of the further development of the theory of ecological functions of soils and geospheres are discussed. It is argued that the study of ecological soil functions is particularly important in the context of the soil conservation policy. The system of soil conservation and preservation of pedodiversity is one of the key issues in nature management. Considerable attention has been paid to this problem in Russia. A series of Red Data soil books for the particular regions of Russia and for the entire country have been published in the recent decades.     

New parasitoids of Paraphytomyza populi (Kltb.) (Diptera, Agromyzidae) in Bulgaria

The parasitoid complex of Paraphytomyza populi (Kltb.) (Diptera: Agromyzidae) was studied in Sofia, Bulgaria in 1997. Poplar leaves with P. populi larvae and pupae were collected from poplar stump shoots and examined in a laboratory. As a result, eleven parasitoid species were established: Chorebus albipes (Haliday) (Hymenoptera, Braconidae), Pediobius metallicus (Nees), Danuviella subplana Erdos, Chrysocharis nephereus (Walker), Chrysocharis pubicornis (Zetterstedt), Diglyphus crassinervis Erdos, Diglyphus isaea (Walker), Diglyphus albiscapus Erdos, Cirrospilus diallus Walker, Cirrospilus pictus (Nees) (Hymenoptera, Eulophidae) and Elasmus sp. (Hymenoptera, Elasmidae). Six species (D. crassinervis, D. isaea, D. albiscapus, C. diallus, C. pictus and Elasmus sp.) have been recorded as new parasitoids of P. populi. The genus Danuviella was found for the first time in Bulgaria. Five species (C. albipes, P. metallicus, D. subplana, D. crassinervis and D. albiscapus) are new records for the fauna of the country. The total mortality of P. populi caused by parasitoids was 19.1% and 49.0% for the overwintering and the summer generations, respectively. P. metallicus was the most important in reducing the pest number.     

Nitrogen Assimilatory Enzymes and Amino Acid Content in Inoculated Foliar Fertilized Pea Plants Grown at Reduced Molybdenum Concentration

ABSTRACT

A possibility to improve nitrogen assimilation in nitrogen fixing Molybdenum (Mo) deficient pea plants was shown. The influence of foliar supplied nutrients in addition to root nutrition resulted in reducing the unfavorable effects of inorganic nitrogen on nodule function and Mo deficiency on the nitrogen assimilatory enzymes. Inoculated pea plants were grown on liquid nutrient solution both with and without Mo. The following variants were tested: Mo supplied plants with root nutrition (F1 + Mo); Mo supplied plants with root and foliar nutrition (F2 + Mo); Mo deficient plants with root nutrition (F1 ? Mo); and Mo deficient plants with root and foliar nutrition (F2 ? Mo). Foliar application of nutrients had a positive effect on the glutamine synthetase and glutamate synthase enzyme activities in the roots and nodules of Mo deficient plants. It was found that the foliar fertilization reduced the inhibitory effect of Mo shortage on the aspartate/asparagine content in the pea shoots.     

Induction of Abortion with Aglepristone in Cats on Day 45 and 46 After Mating

The aim of this study was to test for the efficacy and safety of the use of aglepristone for pregnancy termination on day 45 in cats. Six healthy cats were treated with 10 mg/kg aglepristone sc on day 45 and 46 after mating; six other cats served as untreated controls. The effect of treatment was monitored by general examination, vaginal cytology, ultrasonography and blood sampling for haematology and progesterone determination. Besides, interoestrus interval and next pregnancy including litter size were recorded. The efficacy of treatment was approximately 67% (4/6) with abortion occurring 4–7 days after the first injection and a sanguineous discharge and erythrocytes in vaginal smears for at least 6 days afterwards. The two treated cats that did not abort gave birth to two kittens on day 67 and had a stillbirth of a single kitten on day 71, respectively. As expected enlargement of the mammary glands and lactation were observed in all treated cats. No other treatment‐induced side effects were observed. Progesterone levels at abortion were high (30–140 nmol/l), but were decreased on day 55. Aglepristone treatment did not affect fertility in following cycles. Finally, it can be concluded that late‐term pregnancy termination with aglepristone is possible but due to a success rate of 67% an ultrasonographical examination 7 days after treatment is an inherent necessity to control the effect of treatment.