Second-stage juveniles (I2) of Meloidogyne arenaria consumed more oxygen (P </= 0.05) than M. incognita J2, which in turn consumed more than M. javanica J2 (4,820, 4,530, and 3,970 mul per hour per g nematode dryweight, respectively). Decrease in oxygen consumption depended on the nematicide used. Except for aldicarb, there was no differential sensitivity among the three nematode species. Meloi...

Morphometric comparisons of two populations each of Races 1 and 2 of Meloidogyne arenaria from tobacco, peanut, and soybean in different localities in Florida showed no significant differences in any characters measured by light microscopy. Thirteen morphometric characters of females, 22 of males, and 21 of infective second-stage juveniles were measured for each population. The stylet length in...

Winter survival dynamics of Meloidogyne incognita and M. arenaria were studied at nine sites in Texas for 2 years. Population survival from October until April was variable among sites, ranging from 0.1% to 33%. A negative correlation (r = -0.86, P = 0.01) was observed between initial population, densities in October and survival percentage until the following April. Total population (eggs + J2...

The invasive softshell clam (Mya arenaria Linnaeus, 1758) is native to the northwestern region of the Atlantic Ocean. This species has been introduced in the northeast Pacific and along the European coasts, due to intense naval transports and aquaculture, and it is now present in all the European seas. In this paper we describe seven new microsatellite loci for Mya arenaria. The isolated loci a...

New data on egg development and death rates, and refinements of logic concerning interaction of the nematode and host, were incorporated into a simulation model of a Meloidogyne arenaria and grapevine system. Simulations of field data improved but other areas of weakness in the model were discovered. Two peaks in the egg population curve suggested that the nematode was able to complete two life...

A mixed population of Meloidogyne arenaria race 1 and M. javanica race 3 is reported on peanut from a field in Levy County, Florida. Confirmation of M. javanica on peanut is based on esterase and malate dehydrogenase isozyme patterns resolved on polyacrylamide slab gels following electrophoresis, and perineal patterns. Up to 29% of 290 individual females collected from peanut roots in the field...

Endospores of Pasteuria penetrans were evaluated for their vertical distribution in field soil and their downward movement through soil in the laboratory. In the field trial, the number of endospores attached to second-stage juveniles (J2) of Meloidogyne arenaria race 1 varied greatly in different soil depths. There were higher percentages of J2 with endospores attached in former weed fallow pl...

The latent period in the response of Mya to illumination varies inversely as the duration of the exposure to which it is subjected. The reciprocal of the latent period, measuring the velocity of the process which underlies it, is a linear function of the exposure period. Since the duration of the exposure represents the amount of photochemical activity, it is concluded that the substances forme...

1. The effect of temperature on the reaction time of Mya to light is mainly confined to the latent period. The sensitization period, representing a photochemical process, is changed comparatively little. 2. The relation between the latent period and the temperature is adequately expressed by the Arrhenius equation, for temperatures below 21 degrees C. Above this temperature, the latent period b...