Studies on biological control of Pigeonpea Pod Borers in India

Results of two field experiments, one on SA 1 pigeonpea in rainfed and the other on Co.5 pigeonpea in irrigated conditions revealed thatBacillus thuringiensis var.kurstaki (B.t.k.) (Delfin), its combinations with nuclear polyhedrosis virus ofHeliothis armigera andChrysoperla carnea were as effective as endosulfan in reducing the pod borers,Heliothis armigera andExelastis atomosa. However,B.t.k. 1.25 kg+endosulfan 175 g/ha orB.t.k. 2.5 kg+HaNPV, 250 LE/ha gave better control of damage to flowers and pods thanB.t.k. applied alone on SA 1 pigeonpea. The yield differences between these treatments were not significant. A combination of HaNPV 250 LE/ha+endosulfan 175 g/ha was superior toB.t.k. Similar trend was seen on Co.5 pigeonpea. Release ofC. carnea second instar larvae 1 lakh/ha was not effective in increasing the yield of pigeonpea.     

Development of 8-armed airflow olfactometers for measuring olfactory responses of insect predators

In the present study two types of 8-armed airflow olfactometers are developed, one is for individual test, called the individual olfactometer, another is for population test, called the population olfactometer. Both of them consist of an exposure chamber, 8 odour arms, 8 odour chambers and a sample plate or a sample chamber. In the former, the odour chamber is movable for regulating the distance between an odour source and the exposure chamber. In the latter, the sample chamber can be driven up and down to control the predator population under test to be exposed to the exposure chamber at the same time, and the odour chambers are designed for two functions viz., for placing odour sources and for catching the predator reaching them. By means of the NH₄CL smoke tests, it is clear that the odour airflows in both apparatus are separated in the outward area of the exposure chamber and gradually unified around the center to form the combination of the odour fields, from which the predator under test begins searching the odours. The control tests for random distribution in both apparatus have been conducted to provide the evidence that the same odour source in all odour chambers causes the random selection by the predator. The one-odour tests have been executed to prove the sensitivity of both apparatus for testing insect kairomone responses.     

Geregelte Anordnung von Polyederviren in Insektenpolyedern im Zusammenhang mit deren Umbildung zu bandförmigen Formen

Ohne ZusammenfassungDie Finanzierung der vorliegenden Arbeit erfolgte durch die forstliche Bundesversuchsanstalt in Wien und den öst. Forstverein, wofür an dieser Stelle herzlich gedankt sei. Besonderer Dank gebührt den Herren Dr. Helmut und Dr. Peter Sitte und Frl. N. Pfeifer am physikalischen Institut der Universität Innsbruck (Laboratorium für Elektronenmikroskopie) für die Durchführung der Präparation und der lichtmikroskopischen und elektronenmikroskopischen Aufnahmen des vorliegenden Materiales.     

Vorratsschädllche Insekten in Saudi-Arabien

A survey of insect pests of stored products in three main regions of Saudi Arabia was carried out during two successive years, 1978 und 1979. Randomized samples of different commodities were collected for inspection from 13 localities four times a year. Thirty six species of insect pests belonging to 12 families and 4 orders in addition to 2 hymenopterous parasites were recorded.     

Über die natürlichen krankheiten des goldafters,Euproctis chrysorrhoea L. (Lep., Lymantriidae) 1977 in bayern

Studie were made on the diseases in a population ofEuproctis chrysorrboea L. collected near Munich on vak trees. Three species of parasites found in the larvae were members of Protozoa: a)Pleistophora scbubergi Zwölfer which was the most prevalent (59%) and infected 34% L₃, 62% L₄ and 99% L₅; b) aNosema sp. (probablyNosema kova?evi?i Purrini & Weiser, 1975) which amounted to 1% in mixed infection with a nuclear-polyhedrosis Virus,Borrelina euproctis. This Virus alone (with a particle size of 2–2.5 microns) has been isolated from the 28 larvae (6%). Larvae usually died during the second (from nuclear-polyhedrosis) and third week (from microsporidia) with infection of intestinal-cavity (Pleistophora schubergi), fat-body (Nosema sp. probablyNosema kova?evi?i) and nuclei of adipose tissue (nuclear-polyhedrosis).     

Zur Wirkung von Nemacur- und Temik-Granulaten auf Wurzelgallen-Nematoden (Meloidogyne spp.) bei der Tomate

The susceptibility of the two single populations of root-knot nematodes invading tomato roots,Meloidogyne javanica andM. incognita acrita, in comparison with a mixed population of the two species was investigated to the granular nematicides, Nemacur and Temik. Root-gall indices ofM. incognita acrita were reduced more than ofM. javanica. In addition, root-gall indices of the mixed population and a single population,M. incognita acrita, were the same.     

Fliegenresistenz in der Praxis

Zusammenfassung Auf Grund 8jähriger praktischer Erfahrungen bei der Fliegenbekämpfung wird festgestellt, daß der Erfolg einer Fliegenbekämpfung von einer Anzahl verschiedener Faktoren abhängig ist, die sich je nach den örtlichen und zeitlichen Gegebenheiten in wechselnder Stärke auswirken.     

Tinea vastella Zeller,ein Schädling an Jagdtrophäen in Afrika

Ohne Zusammenfassung     

Über den Einfluß fremder Männchen auf die Nestlingsmortalität bei der Erdmaus (Microtus agrestis L.)

A total number of 55 litters of the field vole was observed in captivity. The litter size was 4.09±1.9 nestlings. 23 litters were obtained from voles which were kept pairwise in cages. The number of newborn was 108 and the mortality within the first two weeks was 11%. Incages with 8 to 20 adults living in communities 18 litters with 73 newborn voles were observed. The mortality was 26%. In 14 cases pregnant females were exposed to strange males 10–16 days after conception. A pregnancy block was not observed. However 74% of the newborn voles were killed from the strange males.