Nematologica 

About: Nematologica is an academic journal. The journal publishes majorly in the area(s): Population & Heterodera. It has an ISSN identifier of 0028-2596. Over the lifetime, 2358 publications have been published receiving 35534 citations.

A Rapid Method for the Transfer of Nematodes From Fixative To Anhydrous Glycerin

Abstract: Eine Methode wird beschrieben bei der Nematoden innerhalb 24 Stunden von der Fixierungsflussigkeit in wasserfreies Glyzerin uberfuhrt werden. Die Nematoden werden nach Fixierung in ein Gemisch von 20 Teilen Aethanol 96%, I Teil Glyzerin und 79 Teilen Wasser gebracht. Das Aethanol in diesem Gemisch wird durch Wasserentzug im Exsiccator mit Aethanol 96% bei 35°-40°C in nicht weniger als 12 Stunden bis zu etwa 95% konzentriert. Danach wird ein Gemisch von 5 Teilen Glyzerin in 95 Teilen Aethanol 96% hinzugefugt. Dieser wird bei 40°C in wenigstens 3 Stunden zu reines Glyzerin konzentriert.

The Relation Between Nematode Density and Damage To Plants

Abstract: An equation for the relation between the density of stem nematodes or virus transmitting nematodes in the soil and the proportion of attacked plants can be derived if two suppositions are made: 1. the "average nematode" is the same at all densities. 2. the nematodes act independently of each other. If now y = the proportion of the plants that is not attacked and P = the density of the nematode then In this equation z is a constant < 1 and equal to the proportion of the plants not attacked at a nematode density P = 1 (competition curve of Nicholson). The results of a pot experiment by Sayre & Mountain and field observations by Kaai are in close agreement with this equation. To describe the relation between the density of populations of root infesting nematodes and the yield of attacked plants an equation must express two phenomena: 1) Up to a certain density (the tolerance limit) the yield is not affected (damage only to tissue that is not essential to the growth of the plant, power of recovery of the plant), 2) a certain minimum yield (Omin) remains unaffected by the nematodes even at the highest densities (because of temporary or continuous inaccessability of part of the host tissue). The equation in which Op = yield at nematode density P, 0max = yield in the absence of nematodes and T = tolerance limit, fulfills these requirements. The results of many experiments reported in the literature are in good agreement with this theoretical relation between nematode density and yield. In most cases Omin is between 0.1 Omax and 0.5 Omax. The tolerance limit depends on the nematode species, the plant species and external conditions.

Transmission of Bursaphelenchus Lignicolus (Nematoda: Aphelenchoididae) By Monochamus Alternatus (Coleoptera: Cerambycidae)

Abstract: A total of 21 beetle species, all of which were associated with deteriorated pine trees, were examined for the presence of Bursaphelenchus lignicolus. Dauerlarvae of this nematode were recovered from adults of four species of the Cerambycidae; Monochamus alternatus, Acanthocinus griseus, Arhopalus rusticus, and Corymbia succedanea. Between 75%-100% of the field population of M. alternatus in the diseased pine forests was contaminated, carrying an average number of 15,000 living nematodes per insect. Dauerlarvae were transmitted to pine tissues via feeding site of the insect on living branches. It appears that M. alternatus plays an important role in the spread of the nematode and on associated wilt disease in pine forests.

Some Observations On Moulting in Caenorhabditis Elegans

Abstract: Moulting of Caenorhabditis elegans has been observed by Nomarski interference contrast microscopy, and by electron microscopy of animals at selected stages. The wild type, cell division mutants and animals in which cells had been ablated by a laser microbeam were examined. The median lateral hypodermis, or "seam", is required for the formation of alae and for dauer larva maturation. During cuticle deposition, large Golgi bodies are seen in the seam cells. The excretory system is not essential for moulting.