Zur Morphologie und Entwicklung von Bracon instabilis Marsh. (Hym., Braconidae), eines Parasiten der Kartoffelmotte,Phthorimaea operculella Zell. (Lep., Gelechiidae) in Ägypten

Bracon instabilis Marshal is an ectoparasite attacking the larvae ofP. operculella in Egypt. According to available literatures, this is the first study onB. instabilis. The laboratory rearing of this parasite was undertaken on the third and fourth larval instars ofP. operculella and the method was mentioned in details. Certain aspects of the morphology of the immature and adult stages were given. The durations of the immature stages of the parasite were estimated at 15 and 25°C and 60±5% R.H. The total durations of the immature stages (from egg to adult) were 39.62 and 11.19 days at 15 and 25°C, respectively.     

Die Lufttemperatur als limitierender Faktor für die Schwärmaktivität zweier rindenbrütender Fichtenborkenkäferarten,lps typographus L. undPityogenes chalcographus L. (Col., Scolytidae)

Single catches of bark beetles in pheromone baited traps were registered by the aid of a new instrument. It consists of an electronical weather station in connection with a pheromone trap with infrared sensors as additional equipment. So it was possible also to register weather data at the moment of every catching event. It could be shown that the flight behaviour of both species of bark beetles was influenced by air temperature.I. typographus did not fly beneath a minimum temperature of 16.5°C. There was also an upper limit of 30°C for flight activity of this species.P. chalcographus has a threshold of temperatures about 16.8–17°C, for activity. No upper limit of temperature could be observed up to 35°C. Both of them,I.typ. andP. chalc., reacted very sensitive and spontaneous to these temperature thresholds.     

The effect of late season damage on the apical bud development of Scots pine seedlings

The effect of Lygus rugulipennis Popp. feeding and artificial damage on the apical bud of Scots pine (Pinus sylvestris L.) late in the growing season was studied on two-year-old seedlings. Lygus feeding in late July and August caused inhibition of bud formation in the subsequent year's shoots, which led to loss of apical dominance and formation of interfascicular buds. Mechanical damage caused by piercing the apical bud with a needle in July, August and October produced scars and malformations on subsequent year's shoots and buds, but did not inhibit bud formation. Damage to the apical meristem could not be detected visually on the dormant bud before shoot elongation.     

Auswirkungen des Einsatzes entomopathogener Nematoden im Freiland auf die Nichtzielfauna, 1. Teil: Coleoptera

Zusammenfassung Von 1988 bis 1990 wurden in vier verschiedenen Gebieten (Buchen-Eichen-Mischwald, Kiefernwaldrand, Getreidefeld und Obstgarten) in der Umgebung von Darmstadt Freilandversuche mit den NematodenstämmenSteinernema feltiae und denHeterorhabditis-Stämmen HL 81 und HD 01 durchgeführt, um deren Auswirkungen auf die Nichtzielfauna zu untersuchen. Die Aufwandmengen lagen bei 0,6 bis 1,0×10⁶ Nematodenlarven/m². Die Käferfauna wurde mit Hilfe von Bodenphotoeklektoren über mehrere Wochen bis Monate auf den nematodenbehandelten Flächen und auf unbehandelten Kontrollflächen erfaßt. Den Schwerpunkt der Auswertungen bildeten die Familien Carabidae, Staphylinidae, Chrysomelidae, Curculionidae und Elateridae. Die Ergebnisse zeigten, daß anscheinend nur wenige Arten einzelner Käferfamilien durch den Nematodeneinsatz beeinträchtigt wurden. Andere Arten traten dagegen auf den behandelten Flächen wesentlich häufiger auf als auf den Kontrollflächen. Mögliche Ursachen für diese Effekte werden diskutiert.

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From 1988 to 1990 field trials with entomopathogenic nematodes were conducted in four different areas (beech-oakforest, pine-forest margin, crop field and orchard) in the surroundings of Darmstadt (FRG). The nematodes used in the trials wereSteinernema feltiae Fil. f.filipjew (syn.S. bibionis Bov.) and theHeterorhabditis strains HL 81 and HD 01; the nematode concentration was 0.6 to 1.0×10⁶ nematodes/m². The coleopteran fauna of treated areas and untreated control plots was investigated by means of photoeclectors. Most attention was paid to the coleopteran families Carabidae, Staphylinidae, Chrysomelidae, Curculionidae and Elateridae. Only a few species of these families seemed to be affected by the nematode application; some other beetle species could be collected even in higher numbers on the treated plots than on the untreated control plots. Possible reasons for these effects are discussed.

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Mit einer Abbildung und 2 Tabellen     

Homogeneous shear stress field of wood in an Arcan shear test configuration measured by means of electronic speckle pattern interferometry: description of the test setup

Wood Science and Technology - Several studies have dealt with the problem of how to measure the shear modulus of small clear wood specimens, avoiding bias from normal compression, bending, tension...     

三种抗性灌木在吉林省的引种应用研究

以沙枣、银莓、牦牛莓为对象,对其在吉林省的生态适应性及耐盐能力进行研究,结果表明:三种抗性灌木的越冬能力、生长性状、物候节律完全适应吉林省西部的生境。通过盐碱胁迫试验证明,三种灌木抗盐碱能力强,其不同种源在吉林省西部困难地段均具有较强的适应性。