Cysts of Heterodera schachtii were treated in a water bath at constant temperatures ranging from 45 - 62.5 C for 1 sec to 28 hr. Treated and untreated cysts were incubated 8 weeks in sugarbeet root diffusate at 24 C to measure emergence of surviving larvae. Within the temperature range of 49 - 54 C, the minimum lethal temperature was proportional to the log time of treatment. No larvae emerged ...

Reproduction of the corn cyst nematode (Heterodera zeae) and its effect on growth of corn (Zea mays) was studied in plant growth chambers at 24, 27, 30, 33, and 36 C. Reproduction of H. zeae increased directly with increase in temperature from 24 to 36 C. Fifteen-cm-d pots of corn seedlings inoculated with a mixture of 5,000 eggs + J2 and maintained for 8 weeks in growth chambers contained an a...

A 1341 bp sequence of the 16S rDNA of an undescribed species of Pasteuria that parasitizes the soybean cyst nematode, Heterodera glycines, was determined and then compared with a homologous sequence of Pasteuria ramosa, a parasite of cladoceran water fleas of the family Daphnidae. The two Pasteuria sequences, which diverged from each other by a dissimilarity index of 7%, also were compared with...

A 4-year systematic survey for the presence of soybean cyst nematode Heterodera glycines in Ohio soybean fields was initiated in 1992. A total of 667 soybean fields in 63 counties was sampled. Heterodera glycines was present in 91 fields in 40 counties based on soil samples collected, and in one field in each of three additional counties based on soil samples submitted to the Plant and Pest Dia...

Heterodera mediterranea completes embryogenic development in 15-18 days at 24 +/- 2 C. On olive and pistachio seedlings the postembryogenic development was completed in 42-50 days at 24-30 C. Juveniles and adults have semiendoparasitic habits and do not penetrate completely into the root tissue. This cyst forming nematode has been detected only on Olea europaea, Pistacia lentiscus, and P. vera....

Abstract The ryegrass cyst nematode, Heterodera mani , is reported from Western Australia for the first time. Cysts were recovered soil samples collected on a broadacre cropping property near town of Esperance. production area dominated by cereal/oilseed rotation and species annual ( Lolium rigidum ) common weed issue in these paddocks. Morphometrics cysts second stage juveniles (J2s) Australia...