Über Wirkungen von Dieldrin auf die Neurosekretion und die Ovarien vonGryllus assimilis F. (Orthopt., Gryllidae)

Effects of Dieldrin on the neurosecretory system and the ovarian development of Gryllus assimilis F. (Orth., Gryllidae)A sublethal dose of Dieldrin induced changes in the neurosecretory system ofGryllus asimilis and entailed degeneration of oocytes. A fall in the haemolymphal acid phosphatase was also noted. By this sublethal Dieldrin could induce sterility inG. assimilis.     

Wirkungen der Fotoperiode und Temperatur auf die Entwicklungsstadien von Acrotylus insubricus Scop. (Orthopt., Acrididae)

Effect of photoperiod and temperature on the developmental stages of Acrotylus insubricus Scop. (Orth., Acrididae) The effect of different temperatures and photoperiods on the developmental stages ofAcrotylus insubricus Scop. was studied. The species has no embryonic or nymphal diapause. The relatively low temperature of the winter months prolonges the incubation period as well as the nymphal development. By rising temperature both eggs and nymphs began to continue their development. The shortest nymphal duration at 27 °C (63.9 days) was obtained when rearing nymphs at long photoperiod (16L:8D), while the longest duration (92 days), was recorded at short photoperiod (8L:16D). In intermediate photoperiod (12L:12D), the nymphal duration was 82.8 days, between the long and the short photoperiods. At 37 °C, the nymphal durations were shorter than at 27 °C and still the shortest at a long day (4310 days) than the two other conditions. The total nymphal mortality was higher at short day-length than that at the other photoperiods tested. The incubation period as well as the percentage of hatching were not affected by the different photoperiodic regimes while the low temperature prolonges the incubation period and nymphal development. The higher temperature (37 °C) tended to mask or abolish the effect of the photoperiod while the moderate temperature (27 °C) clarified this effect when the two factors were combined together.     

Wirkungen von zwei Insektenwachstumshemmern auf die Eiablage und Eier vonHeliothis armigera (Hb.) (Lep., Noctuidae)

The effect of two insect growth inhibitors (PH-6040 and H-24108) on the fecundity, hatchability, viability and sterility of eggs laid by treatedHeliothis armigera female moths had been studied. Moths treated with these compounds laid less number of eggs than untreated moths. The egg laying capacity decreased as the concentration of any compound increased and vice versa. The same trend could be applied for egg hatchability and sterility as being affected by insect growth inhibitors and their concentrations.     

Geschlechtsunterschiede im Fraßverhalten unter der Einwirkung eines Neemsamenkern-Extrakts (NSKE) beiChrotogonus homalodemus (Blanch.) (Orthopt., Acrididae)

The feeding habits of males and females ofCh. homalodemus showed some differences. In the control the male consumed less than the female. The reluctant feeding habit of the females leads to the suggestion that the repellent effect of NSKE lasts longer than the exposure time. A choice test showed thatCh. homalodemus did'nt feed on treated cabbage leaves when untreated ones were available.     

Wirkungen von zwei Antihäutungs-Substanzen auf die Raupen von Spodoptera littoralis (Boisd.)

Effect of two antimoulting compounds against the larvae of Spodoptera littoralis (Boisd.) Dc 201 and 202 are representatives of a new class of insecticides. Susceptibily of three instars ofSpodopteram littoralis (i.e., 1st, 3rd, and 6th) is demonstrated. Their insecticidal activity demmonstrates itself as a failure to moulte or pupate, resulting in death. Treated larvae remained seemingly unaffected until they had entered the apolytic stage preceding the actual sheding of the exuvia.Dc 202 was more active and more persistant on treated cotton plants than DC 201, particularly at the lower oncentration; the residual activity of the former compound extexded much longer than 15 days.     

Über Wirkungen starker und direkter Industrie-Immissionen auf einen Zerreichen-Bestand (Quercus cerris L.)

Some impacts of the heavy and direct pollution coming from an aluminium foundry and a heating power station on aQuercus cerris L. stand were examinated in Central Transdanubia, Hungary. The greater part of the wooded vegetation, on more than 300 ha, is perished by the pollution. The species-richness of the wooded vegetation of the damaged area is 56% less than that of the control. Only 7 wooded species were found on the damaged area comparing with the 16 species found on the control area. TheCrataegus monogyna L. seemed to be the most resistant. Only this shrub could be found at the survey-point closest to the aluminium foundry. The average surface of the turkey oak leaves on the control area is more than five times as large as on the damaged area. The pollution caused at least 66 mm (more than 50 %) loss in the diameter growing of the damaged turkey oak stand during 35 years.     

Zur Wirkung zweier Juvenilhormon-Analogen auf die Baumwolleule Spodoptera littoralis (Boisd.) (Lep., Noctuidae)

Effects of two juvenile hormone mimics on the Egyptian Cotton Leaf-Worm, Spodoptera littoralis (Boisd.) (Lep., Noctuidae) Two analogues of insect juvenile hormone were tested for effects on eggs, 6th instars, and pupae ofSpodoptera littoralis (Boisd.). These were 3,7-dimethyl-6-epoxy-2-nonene-1-oxy (3,4-methylene-dioxybenzene), and 3,7-dimethyl-6-epoxy-2-nonene-1-oxy (4-chlorobenzene). The purpose was to observe effects of these chemical on fecundity, metamorphosis, and survival. Against 24-hour-old eggs the chloro-derivative was much more potent inhibitor of embryonic development than its methylene dioxy-analogue. Against 6th instar larvae these two compounds were equipotent in resulting intermediate forms incapable of survival. Against pupae these two analogues at 6–8 g/insect caused deformities and reduced fecundity and fertility of the survival adults to more than 90% of their normal levels.     

Wirkungen einesBacillus thuringiensis-Präparats und eines Juvenilhormon-Analogons über den Erdboden aufSpodoptera littoralis (Boisd.) (Lep.,Noctuidae)

Summary Sensitivy of Spodoptera littoralis (Boisd.) to soils treated with preparations of Bacillus thuringiensis and of a juvenil hormone analogue Various instar larvae ofSpodoptera littoralis were exposed to soil treated, with aBacillus thuringiensis-containing preparation (Bactospeine) and a juvenile hormone analogue (Ro 20–36 000).After treatment with Bactospeine, only high concentrations could affect emergence. Suppressed egg laying and sterility were the most marked effects. Also, the produced eggs were smaller in size.The juvenile hormone analogue showed high activity, particularly against freshly moulted 6th. instar larvae. Greater effects were elicited after ecposing the larvae to treated soil than to treated leaves for 48 hours. It appears to be fairly stable in soil. Its morphogenetic activity could be detected 60 days after application.     

Untersuchungen zur Wirkung eines Kernpolyeder-Virus ausLeucoma salicis L. (Lep., Lymantriidae) auf einige Lymantriiden-Arten

Zusammenfassung Es wird ein Nuclear-Polyedrose-Virus ausLeucoma salicis-Raupen beschrieben und das Ergebnis von Untersuchungen über seine Wirkung auf 5 Lymantriiden-Arten mitgeteilt. Das Virus zeigte hohe Pathogenität gegenLymantria dispar, Euproctis chrysorrhoea, Leucoma salicis undOrgyia antiqua, dagegen geringe gegenLymantria monacha. Die Lt₅₀- und LD₅₀-Werte für die verschiedenen Wirte werden mitgeteilt.

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On cross infectivity of a nuclear polyhedrosis virus isolated fromLeucoma salicis to some related Lymantriidae

A virus strain isolated from larvae ofLeucoma salicis L. (Lep., Lymantriidae) was tested against 5 species of Lymantriidae. This virus showed a high pathogenicity againstLymantria dispar, Euproctis chrysorrhoea, Leucoma salicis andOrgyia antiqua. The nun moth,Lymantria monocha, was less suspectible to the nuclear polyhedrosis virus; this could be shown by aid of the calculated values of the Lt₅₀ and the LD₅₀.

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Mit 5 Abbildungen und 5 Tabellen     

Beobachtungen über die Taxonomie und Bionomie vonUrocerus gigas (L.) undSirex juvencus (L.) (Hym., Siricidae)

Ohne Zusammenfassung     

Über kombinierte Wirkungen eines Juvenoids (Altosid) und eines Bacillus-thuringiensis-Präparats (Bactimos) auf Larven der Stechmücken Culex pipiens molestus Forsk. und Theobaldia longiareolata Macq. (Dipt., Culicidae)

Exposing second and fourth instar larvae ofCulex pipiens molestus for 24 h to Altosid increased their tolerance to Bactimos. The interaction was apparent in fourth instar larvae treatment especially at the higher concentrations. Exposure bactimos to Altosid for 72 hours decreased its efficacy against the fourth instar larvae ofCulex pipiens molestus. The LT₅₀ values were significantly lower in larvae treated with Bactimos only than that treated with Altosid and Bactimos. Altosid briquets increased significantly the tolerance ofTheobaldia longiareolata larvae toBacillus thuringiensis var.israelensis at all concentrations tested. Generally, pretreatment mosquito larvae with Altosid followed by Bactimos, increased the tolerance of larvae to the bacterium, this may be due to the toxic effect of Altosid on the bacterium or to the changes in the physiological status of the treated larvae to tolerate the effect of bacterium. On the light of these studies, Altosid exhibited detrimental effect on the efficacy ofB. thuringiensis var.israelensis againstC. pipiens molestus andT. longiareolata larvae. Therefore, interactions between Altosid and Bactimos could not fit the integrated control of mosquitoes.     

Über den Crowding-Effekt auf die Eiablage vonOligonychus mangiferus (Rahm. & Sap.) (Acar., Tetranychidae)

Crowding adversely affects egg laying inOligonychus mangiferus. The crowding effect is independent of food scarcity effect. Involvement of population density regulating factors, presumably pheromones can be considered a distinct possibility.     

Zur Wirkung der Partikelgröße der Imaginalnahrung auf die Eizahl vonTribolium castaneum (Hbst.) (Col., Tenebrionidae)

Whole and intact wheat grains or those broken into 2 or 8 equal pieces and supplemented with yeast provided as adult food to individuals ofTribolium castaneum considerably reduced the egg output in these beetles although their larvae were reared on finely powdered yeast-supplemented whole wheat flour. However, egg fertility in all the three dietary situations was 100%.     

Der Einfluß der Schadenerregung des Kiefernspinners (Dendrolimus pini L.) auf das Wachstum eines Kiefern-Jungbestandes

The effects of injuries caused byDendrolimus pini L. on height and diameter growth as well as on mortality of 17 years old Scots pine were examinated in the year of damages and in the two following years. Due to the damages by caterpillars the height growth was reduced to 54% and that of diameter to 45%. The mortality of heavily damaged trees was 50–60% and that of defoliated trees 100%.     

Nematizide Wirkungen einiger Herbizide auf den Wurzelgallen-Nematoden Meloidogyne javanica (Treub.) in Tomatenwurzeln

The studies showed that herbicides i. e. Treflan had side effects in controllingMeloidogyne javanica (38.1% reduction in nematode population) followed by Gramoxone (15.1% reduction), while Dowpon “S” and Cotoran showed lethal phytotoxic effects on the tomato plants.     

Zur Wirkung zeitlich nicht konstanter Phosphorwasserstoffkonzentrationen auf den KornkäferSitophilus granarius (L.) (Col., Curculionidae)

Zusammenfassung Die Mortalität des KornkäfersSitophilus granarius nach Phosphorwasserstoffbegasungen ist stark von der Entwicklungsgeschwindigkeit der Gaskonzentration in der Anfangsphase der Begasung abhängig. Mit 0,08 g PH₃/m³ — schlagartig und konstant appliziert — werden bei 20°C und 65% rel. Feuchte innerhalb von 48 h alle Tiere abgetötet. Bei langsam ansteigender und wieder abfallender Gaskonzentration, wie sie in Getreidelägern bei Begasungen auftritt, sind dazu 6 g PH₃/m³ als Anfangsdosierung erforderlich, wenn die Versuchskammer mit 5% ihres Volumens pro Stunde mit frischer Luft gespült wird. Eine mittlere Konzentration von 1,55 g PH₃/m³, die sich aus dem Integral der Konzentrationskurve mit 6 g PH₃/m³ ergibt, führt in 10 Stunden zu 100% Mortalität.Etwa die 20fache Wirkstoffmenge bzw. die 5fache Zeit wird somit benötigt, um bei praxissimulierenden Begasungsbedingungen die gleiche Wirkung zu erzielen, wie bei konstanten Konzentrationen.Verschiedene Erklärungsmöglichkeiten werden diskutiert.

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Response of the granary weevilSitophilus granarius (L.) to gradually increasing and decreasing phosphine concentrations

The response of the granary weevilSitophilus granarius to phosphine differs strongly depending on whether the insects are exposed to a gradually increasing concentration of the fumigant, as would be the case in a storage when PH₃-releasing formulations are used, or to a constant concentration as is usually done in laboratory experiments.With an initial dose of 6 g PH₃/m³ it takes 48 h at 20°C and 65% r.h. to kill all insects when the fumigation chamber is purged with fresh air at a rate of 5% of its volume per hour. A constant concentration of only 0.08 g PH₃/m³ is necessary to give the same mortality in the same time.An average concentration of 1.55 g PH₃/m³ — derived from the integrated concentration curve with an initial dose of 6 g PH₃/m³ — kills all insects within 10 hours.Different mechanisms of response of the weevils to phosphine are discussed.

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Mit 3 Abbildungen und 3 Tabellen     

Zur Wirkung der Nahrungspflanze auf die Entwicklung und Vermeharung der Baumwolleule,Spodoptera littoralis (Boisd.) (Lep.,Noctuidae)

Effect of some host plants on development and reproduction of Spodoptera littoralis (Boisd.) (Lep., Noctuidae) Investigations were performed to study the effect of some hostplants on development and reproduction capacity of the Egyptian cotton leaf-worm,Spodoptera littoralis (Boisd,), Larval and pupal weights, life span, average number of eggs laid per female and percent digestability for fifth instar larvae were measured. Cotton leafworm was able to complete its life cycle only when reared on eigher castor bean leaves, clover, sweet potato leaves, or the outer green cabbage leaves. Chlorophyl-free inner white cabbage leaves, maize, and grape vine are nutritionally insufficient to support growth and development of larvae and, in turn, cause increase in span of survived larvae and none of these larvae metamorph to pupae. It seems that there is a positive correlation between larval and pupal weights and average number of eggs laid per female; the greater the weight of larvae and pupae the higher the number of eggs laid. Castor bean leaves seem to be the most favorable host plant for rearing cotton leafworm in the laboratory. The differences and variations in the growth and development of cotton leafworm due to feeding on different host plants are discussed.