FREE-LIVING SOIL NEMATODE POPULATION DIVERSITY DYNAMICS AT AN ASIMINA TILOBA SITE IN VIRGINIA. Sarah R. Marzec & Theresa M. Grana, Department of Biological Sciences, Univ. of Mary Washington, Fredericksburg VA, 22401. Nematodes are microscopic roundworms that are highly successful in many environments. The model organism Caenorhabditis elegans is specifically a free-living nematode which can be...

Cartesian Diver (1) and manometric (2) techniques have frequently been used to measure the respiration rates of nematodes. However, the sensitivity and ease of operation of the polarographic oxygen-sensing equipment currently available offers a technique of great future value to plant nema-tologists. Our recent experience with the YSI Model 53 Biological Oxygen Monitor (Yellow Springs Instrumen...

Corn yields were measured after application of nematicides in 16 experiments, mostly in medium-to-heavily textured soil, at 12 locations in Iowa during 1973-1976. The average maximum yield increase in plots treated with nematicides was 21% over yields in untreated plots. Yields were correlated negatively with nematode numbers or nematode biomass in nearly all comparisons. Correlations of nemato...

In a single experiment, field-grown Louisiana sugarcane was augmented with phytoparasitic nematodes, treated with aldicarb, or left untreated in both weedy and weed-free habitats to study interactions among nematodes, weeds, sugarcane, and sugarcane free amino acid titers. Aldicarb reduced three of the six phytoparasitic nematode genera at various times during the two growing seasons and was as...

The influence of plant resistance on the size of individual root-knot nematodes was determined in greenhouse experiments. Five genotypes of alyceclover were inoculated with second-stage juveniles of Meloidogyne incognita race 3 or M. arenaria race 1. Plants were harvested at selected intervals and stained for detection of the nematodes, which were dissected from the roots. Length, width, and sa...

Transmission of pinewood nematode, Bursaphelenchus xylophilus, to mature, field grown Scots pines through feeding wounds of Monochamus carolinensis was investigated by caging nematode-infested beetles on pine branches for 24 hours. Nematodes were transmitted to 31 of 64 branches. Frequency of successful transmission was independent of the sex of the beetle but dependent upon beetle age. Transmi...

A common feature of plant-parasitic nematodes on annual crops is that they have an uneven distribution within a field and the symptoms of damage, normally associated with high population densities, occur in patches (McSorley,1998). Where a susceptible annual crop is replanted year after year the nematodes spread and the patches increase in size and eventually coalesce (Brown, 1987; Swarup and S...

Nematodes are the most abundant type of animal on earth, and live in hot springs, polar ice, soil, fresh and salt water, and as parasites of plants, vertebrates, insects, and other nematodes. This extraordinary ability to adapt, which hints at an underlying genetic plasticity, has long fascinated biologists. The fully sequenced genomes of Caenorhabditis elegans and Caenorhabditis briggsae, and ...

Nematodes that parasitize insects are known as entomopathogenic nematodes (EPNs). Molecular identification and genotyping of entomopathogenic nematodes are prerequisites for their proper classification, biodiversity studies, and their potential use in biological control programs. In the present study, a strain of entomopathogenic nematodes was isolated from the cultivated lands in Meerut region...

No. 6 at Keller Golf Course in St. Paul Although our random probing with a Hoffer tube of 142 greens on 36 golf courses back in 1969 and 1970 did work to provide documentation that just about every established green (139/142) that we sampled was infested with plant nematodes, I am not necessarily comfortable in recommending such "randomness" with regard to sampling. Plant pathogens (organisms t...