Reports of sections

Ohne Zusammenfassung

---

Reports of sections

     

竹子遗传改良的措施

竹子是一种非常重要的非木质林产品.用途很广泛.它在纸浆造纸工业中用途甚广.竹子的需求增长很快.树木改良技术可填补空白.优良植株可提高竹子产量,来满足不同规模的定植苗,选择丛生可产出多株繁殖.常规的体细胞杂交最初也能诱导理想的基因.采取原地和异地保护的方法,对竹子生物多样性加以保护.     

Overwintering ofTrichogramma evanescens Westw. in Egypt (Trichogrammatidae,Hymen.)

Eggs ofA. kuehniella parasitized byT. evanescens were held outdoors in a shadow place during the period from November 20th, up to parasite emergence. Blackness of the parasitized eggs appeared 3 days later.Overwintering lasted for 99 days starting from 24th, November till 2nd of March at an average temperature of 10.1° C. When temperature increased to an average of 16.6° C, the parasitoids continued their development for 5 days till the emergence of adults.Emerged adult parasitoids showed relatively normal bioaspects as those reared in the laboratory.With 2 tables     

Effect of mating on egg production in two species of predatory mites,Agistemus exsertus Gonzalez andPhytoseiulus persimilis Athias — Henriot

The influences of single and multiple matings on egg production in the two predacious mitesAgistemus exsertus Gonz. andPhytoseiulus persimilis Ath. — Hen. were investigated in the laboratory. with both species egg production was increased as a result of multiple matings, but this increase was insignificant. In addition, mated females ofA. exsertus commenced oviposition one day earlier compared to unmated ovipositing females.With 1 table     

Zur Beschreibung der Waldstruktur — Erwartete und beobachtete Arten-Durchmischung

Zusammenfassung Am Beispiel zweier Best?nde wird ein neuer Ansatz pr?sentiert, mit dem sich die Ergebnisse derArten-Durchmischung ohne relativen Vergleich mit den Werten eines anderen Bestandes beurteilen lassen. Den als konstant betrachteten Stammfu?koordinaten werden die Attribute Baumart und Brusth?hendurchmesser durch zuf?lligePermutationen zugeordnet. Dadurch entstehen Zufallsw?lder, die die gleiche Artenzusammensetzung besitzen wie die Originalbest?nde. Der Vergleich der beobachteten Durchmischungswerte mit den bei zuf?lliger Verteilung zu erwartenden ergibt eine geeignete Interpretationshilfe. Summary By using two forest stands as an explanatory example a new approach is presented, which helps to evaluate the results of thespecies mingling without necessitating a relative comparison of the values to another stand. The tree attributes tree species and diameter at breast height are reassigned to the constant coordinates defining tree position by randompermutation. Random forests are thereby generated, which have an identical species composition as that of the original stands. The comparison of the observed mingling values to the expected is to aid in interpretation.     

Eiablage des RapsstengelrüßlersCeutorhynchus napi Gyll., in Abhängigkeit der Stengellänge bei verschiedenen Rapssorten

Eight trails with randomized block design with 4–8 rape varieties and 4–6 repetitions were performed from 1988–93 at two locations (Zurich-Reckenholz and Zollikofen). From each plot 10 plants were removed at one or two dates and the number of eggs and larvae of the stem weevilCeutorhynchus napi were counted in the laboratory. In addition in 1991 and 1993 the number of splitted stems were recorded. The results show thatC. napi neither prefers O-varieties nor OO-varieties for egg deposition. But there is a clear preference for a distinct developmental stage of the rape plants. The stem weevil prefers plants up to 22 cm hight for egg laying. On the average early vvarieties were significantly less infested by the stem weevil than moderately-early to late flowering varieties. The O-varieties Bienenu and Jet Neuf had fewer splitted stems than the OO-varieties and among them Idol and Eurol had fewer than Arabella and Libravo. The risk for splitted stems is increasing with higher infestation.     

The effects of different rearing diet media on the irradiated pupae and adults of flour beetle,Tribolium confusum (J. du val)

In this study, gamma radiation was applied between 10–120 Gy at 10 dose levels for 2–4 days-old pupae; 10–150 Gy at 11 dose levels for 12–14 days-old adults ofT. confusum. All experiments were carried out in incubators maintained at 27±0.5°C and 70±5% relative humidity. The development of adults reared on different flours from irradiated pupae was not prevented by exposing these stages investigated doses. Rapidly developing confused flour beetle were more susceptible to killing by gamma radiation. Adults that emerged from treated pupa had elytral and other deformities. In barley flour, rate of deformed individuals were higher than the other rearing media. LD₅₀, LD_99,9 and SD_99,9 values for wheat flour were high compared with both barley and maize flour. For adult treatment, there were differences in survival among rearing diets especially at doses of 40, 50 and 60 Gys. But there were no differences for LD₅₀ and LD_99,9 values at adult stage, indicating little influence of rearing medium on susceptibility of adults. On the other hand, there were little differences between rearing diets for SD₅₀ and SD_99,9.With 6 tables and 4 figures