Similar host ranges were found for Heterodera schachtii and a race of H. trifolii parasitic on sugarbeet in The Netherlands. Twenty-nine of 41 plant accessions evaluated were susceptible to H. trifolii. Five breeding lines of the interspecific hybrid Beta vulgaris-B. procumbens which are resistant to H. schachtii were highly susceptible to H. trifolii. An accession of B. maritima with partial r...

Under field conditions, species displacements have occurred in different directions between the same invasive species of leafminers (Diptera: Agromyzidae). Liriomyza sativae (Blanchard) was displaced by L. trifolii (Burgess) in the western United States, with evidence suggesting that lower insecticide susceptibility of L. trifolii is a factor. However, in Japan, the opposite has occurred, as L....

Earlier studies on the respiratory systems in symbiotic nitrogen fixation (Wilson, 1938) indicated that the root nodule bacteria (Rhizobium spp.) reduce methylene blue anerobically in the presence of many organic compounds. With few exceptions, the efficiency of a given substrate as a hydrogen donator was approximately the same whether molecular oxygen or methylene blue was used as the hydrogen...