ABSTRACT
Due to Israel's successful agricultural production and diverse climatic conditions, plant-parasitic nematodes are flourishing. The occurrence of new, previously unidentified species in Israel or of suggested new species worldwide is a consequence of the continuous withdrawal of efficient nematicides. Among plant-parasitic nematodes, migratory endoparasitic species of the genus Pratylenchus are widely distributed in vegetable and crop fields in Israel and are associated with major reductions in quality and yield. This review focuses on the occurrence, distribution, diagnosis, pathogenicity, and phylogeny of all Pratylenchus species recorded over the last few decades on different crops grown throughout Israel-covering early information from nematologists to recent reports involving the use of molecular phylogenetic methodologies. We explore the accepted distinction between Pratylenchus thornei and Pratylenchus mediterraneus isolated from Israel's northern Negev region, and address the confusion concerning the findings related to these Pratylenchus species. Our recent sampling from the northern Negev revealed the occurrence of both P. thornei and P. mediterraneus on the basis of molecular identification, indicating P. mediterraneus as a sister species of P. thornei and their potential occurrence in a mixed infection. Finally, the efficiencies of common control measures taken to reduce Pratylenchus' devastating damage in protected crops and field crops is discussed.
ABSTRACT
The greater date moth (GDM), Aphomia sabella Hampson (Lepidoptera: Pyralidae: Galleriinae), is a serious pest of date palms, Phoenix dactylifera. The release of volatiles from both males and females was investigated using sequential SPME/GC/MS analysis. Males release a complex mixture of compounds in a circadian rhythm during the night between 03:00 and 05:00 hr. Six compounds were identified: benzaldehyde, sulcatol (6-methyl-5-hepten-2-ol), geranyl acetone [(E)-6,10-dimethyl-5,9-undecadien-2-one], phenylacetaldehyde, 2-phenylpropenal, and (R)-fuscumol [(R)-(E)-6, 10-dimethyl-5, 9-undecadien-2-ol]. Benzaldehyde, sulcatol, and geranyl acetone were found only in trace amounts. These compounds were in glands located in the forewing of males only. Small amounts of acetoin and 2,3-butanediol were found sporadically in the SPME/GC/MS analyses of volatiles from females, and these compounds probably originate from microorganisms. This is the first finding of a circadian release of male-specific compounds in moths. GC/EAD analyses with synthetic standards of compounds released by males showed that the female antenna is stimulated by all six compounds, while the male antenna responded only to phenylacetaldehyde. A possible pheromonal role for the male-specific compounds is suggested by the circadian rhythm of their release and the EAD response of females to them. However, trapping tests with the main male-specific compounds in screen cages in the laboratory or in the field did not reveal any significant behavioral responses from females or males. Copulation in the laboratory was observed only in the presence of date palm tissue, thus suggesting that sexual communication and mating of GDM moths probably occurs in the crown of date palms.
