Feinstruktureller und histochemischer nachweis des transportepithels am ventraltubus symphypleoner collembolen (Insecta, Collembola)

Feinstrukturell ist das Transportepithel am Ventraltubus symphypleoner Collembolen (Sminthurides aquaticus Bourlet 1842) durch Einfaltungen der apikalen und basalen Zellmembran und durch zahlreiche Mitochondrien gekennzeichnet. Die Cuticula oberhalb des Transportepithels besitzt die Fahigkeit zur Chloridakkumulation. Die wesentliche Funktion des Transportepithels besteht wahrscheinlich in der Absorption von Ionen und Wasser.

Biology of Soil Invertebrates

Grape root as habitat: overwintering and population dynamics of grape phylloxera (Daktulosphaira vitifoliae Fitch) in temperate climate viticulture

Background and Aims Daktulosphaira vitifoliae Fitch (grape phylloxera, Phylloxeridae) is one of the most devastating pests in viticulture, mainly because of their root feeding activity. Up to today fundamental relations between belowground habitat and population dynamics remain unclear. In this 2-year study, we investigated the relations between grape phylloxera population and phenotypic traits of roots and feedings sites. Methods and Results We extracted root and soil samples frequently of two closely related mature rootstocks [Vitis berlandieri × V. riparia (cvs 5C and 125AA)]. We quantified and characterised larval population and crowding and assessed root gall pigmentation, root morphol…

Short-term effects of different tillage in a sustainable farming system on nematode community structure

This study investigated the effects of different tillage practices on the nematode community structure. The different tillage systems were: untilled control, conventional deep plough, two-layer plough and cultivator. Sampling was carried out in a field experiment at Worrstadt-Rommersheim (Rhineland-Palatinate, Germany) in order to study the effects of these tillage systems in a sustainable farming system. Soil samples were taken every 3 months from June 1994 to March 1995 and divided into two depths of 0–10 and 10–20 cm in order to study the vertical distribution of nematode density and community structure. Nematode density was significantly reduced after the first tillage. The second tilla…

Ecophysiological and morphological features of glacier-dwelling Collembola

Collembola predominantly live in soil, and on the soil surface and its neighboring strata. Some species also dwell in extreme habitats in the arctic and antarctic regions and in the high alpine zones.1–8 Collembola constitute 14–22% of all arctic insect species,9,10 and in tundra and northern forest regions with snow and frost prevailing for the best part of the year they constitute an essential part of the winter-active fauna.11–15 Snow Collembola are reported to occur in masses also in the temperate climate zones of central Europe with species like Hypogastrura socialis, Isotomurus palustris und Isotoma hiemalis frequently among them.16,17 According to Zettel,18 the surface activity of I.…