The Entomophthorales of Israel and their arthropod hosts

Species of entomophthoraceous fungi attacking insects and mites are very well represented in Israel. In the last decade, 22 species ofEntomophthora sensu stricto, Triplosporium, Zoophthora, Conidiobolus, and others under the designationEntomophthora sensu lato, have been identified, of which three are new species:Entomophthora turbinata, Zoophthora erinacea andZ. orientalis. Fiftyfour host-pathogen combinations hitherto not recorded in Israel are listed, of which 19 insect species are new hosts of entomophthoraceous species anywhere.     

Review: Date palm arthropod pests and their management in Israel

This review summarizes the current knowledge on the distribution, natural history, economic importance and management of 16 major species of date palm pests in Israel. Another 15, rarely occurring, pest species are also identified. Research on the date palm pests in Israel was initiated against a background of severe outbreaks of scale insects in the late 1950s. These outbreaks were caused mainly by unrestrained use of organophosphates. This situation led to the gradual development of an Integrated Pest Management (IPM) program, which was implemented first against scale insects and later against fruit pests. The IMP approach resulted in successful control of the scale insects, up to the present, whereas agrotechnical and crop management procedures, including covering the fruit bunches with plastic nets and early harvesting of several date cultivars, were successfully applied to achieve efficient control of the fruit moths. In addition, the use of chemical compounds in date plantations was drastically reduced and restricted to heavy foci of pest infestation. In time, microbial control, mainly application ofBacillus thuringiensis products against the lesser date moth, and the use of pheromone traps for monitoring and controlling red palm weevil, enabled further reductions in the use of synthetic insecticides. The overall change in pest management also significantly improved the preservation of natural enemies of the pests in the plantations. Whereas in the 1950s the major problems were caused by the parlatoria date scale and the green scale, in the early 2000s the key pests in date plantations in Israel are the lesser date moth and sap beetles in most of the date-growing areas, and spider mites which are restricted to the Arava Valley. Future management of the first two of these pests should rely on an improved monitoring system and integration of pheromone application for reduction of the population and damage. Efforst should be made to prevent the red palm weevil, which currently is a potential pest, from becoming an actual key pest in date plantations.     

The occurrence of bacterial blight of peas in Israel

Bacterial blight of peas was found for the first time in Israel, so far in two different regions. It was identified according to pathogenicity tests, appearance of symptoms, and physiological characteristics of the bacteria.     

Status of pesticide resistance in arthropod pests in Israel

A complex of events and factors, pertinent to a specific insect and insecticide, governs the development of resistance to insecticides. In Israel, resistance to conventional and novel insecticides occurred in insect pests such asBemisia tabaci andSpodoptera littoralis (that damage agricultural crops),Tribolium castaneum and other flour beetles (that contaminate stored products), andPediculus humanus spp., house flies and mosquitoes (that threaten public health). In the mid-1980s an insecticide resistance management (IRM) strategy was established for all cotton grown in Israel and is being adjusted on a yearly basis as needed. At present, insect pest management and IRM strategies are being developed and implemented area-wide for three regions in Israel: Bet She’an Valley, western Galilee, and western Negev. There are several research groups now working in Israel on various aspects of resistance including occurrence, mechanisms, and management practices. This paper offers a tentative review of the status of insecticide and acaricide resistance in pests in Israel.     

A list of arthropod pests of avocado and pecan trees in Israel

Lists are given of arthropod pests of avocado and pecan trees in Israel. These include ten new pests of avocado and three of pecan. The pests of economic importance on avocado includeBoarmia (Ascotis) selenaria (Schiff.) (Geometridae, Lepidoptera) andHeliothrips haemorrhoidalis (Bouché) (Thrypidae, Thysanoptera). The pests of importance on pecans includeEmpoasca decedens (Paoli) (Jassidae, Homoptera),Zeuzera pyrina L. (Cossidae, Lepidoptera), andMonellia costalis (Fitch) (Aphididae, Homoptera).     

The occurrence of Fusarium crown and root rot of tomato in Israel

Based upon symptomatology and the results of pathogenicity tests, it has been shown that the Fusarium crown and root rot organism of tomato — previously reported only from North America and Japan — is present in Israel.     

Seasonal history ofOrthotomicus erosus (Coleoptera: Scolytidae) in Israel

Observations on the seasonal history ofOrthotomicus erosus (Wollaston) (Coleop-tera: Scolytidae) were conducted on trap-logs within pine plantations in Israel. Seven annual generations were observed in the coastal plain. The average development period from the entrance of the parents into the host until the emergence of the brood was 60 days in spring, 30 days in summer, 66 days in autumn, and 75 days in winter. Data are presented on duration of the colonization process, parent activity within the host, brood development and brood emergence. To overwinter,O. erosus aggregates on unused bark portions of the breeding host, or on pines, usually with a smooth thin bark, affected by other borers. Overwintering occurred between mid-October and February.O. erosus does not mate before emergence. Mating occurs not only in the nuptial chamber but also during maturation feeding and the overwintering period.     

百合鳞茎有害节肢动物调查与防治

百合是江西省特种经济作物之一,是一种经济价值较高的农作物,可食、药用,有润肺止咳、安神、补中益气之功能,是一种很好的滋补品,其鳞茎富含淀粉、蛋白质、脂肪及多种人体所需的维生素等,还可供观赏用。江西素有栽培百合的历史和经验。发展百合生产,是提高农民收入、增加出口创     

The occurrence of a member of theCirculifer tenellus species complex (Homoptera: Cicadellidae: Euscelini) in Israel

Among leafhoppers of the genusCirculifer, there are several important pests of several crops and vector agents of plant diseases. In this report, we describe the occurrence of a leafhopper species closely related to theCirculifer tenellus group, with characteristics that may classify it asC. dubiosus. This insect was found in nature breeding onAtriplex halimus L., a weed belonging to the Chenopodiaceae, mainly in the Jordan Valley. In captivity it produced one generationon A. halimus over a period of almost 45 days at 25°C. The variations of observed structural differences among members of this taxon and their biological significance are discussed.     

Dose-response relationships between phytopathogenic bacteria and their hosts

Theories on the relationships between the challenge dose of phytopathogenic bacteria and the quantal response of the host plant are discussed and applied to experimental results. In a number of cases the extent of disease was directly proportional to the dose, which is an indication of independent action. Departures from linearity in the relationships were ascribed tointer alia a shortage of multiplication sites, antagonism amongst the cells of the pathogen and heterogeneity of the tested host plants with respect to susceptibility. In a few host-pathogen combinations, dose-response relationships showing an upward curve were found; this is probably an indication of facultative synergism. The relationships found in homologous and heterologous host-pathogen combinations were similar. The implications of the above findings for the quantitative study of factors affecting the susceptibility of plants to bacterial infection are discussed.Samenvatting Na een bespreking van de theorieën over de relatie tussen het aantal fytopathogene bacteriën per inoculatie en de al-of-niet respons — waarbij dus de grootte van de individuele respons niet in acht genomen wordt — worden deze theorieën getoetst aan de resultaten van proeven die in de literatuur beschreven zijn. Onderschied wordt gemaakt tussen proeven waarin de proporties en die waarin de aantallen geslaagde inoculaties bepaald zijn. Verder is een vergelijking gemaakt tussen homologe en heterologe combinaties van waardplant en pathogeen.Waar de proporties geslaagde inoculaties werden gemeten, vond ik in een aantal gevallen evenredigheid tussen dosis en respons, mits een transformatie werd toegepast voor veelvoudige infectie. Dit is een aanduiding dat de cellen van het pathogeen elkaar niet beïnvloeden. Afwijkingen van dit rechtlijnig verband kunnen o.a. worden toegeschreven aan antagonisme tussen de cellen van het pathogeen, aan heterogeniteit in vatbaarheid van de waardplanten of aan een beperkt aantal vermeerderingsloci.In drie gevallen werd een naar boven gekromde lijn gevonden, hetgeen waarschijnlijk wijst op facultatief synergisme.In proeven waarin de aantallen geslaagde inoculaties gemeten werden, vond ik in de literatuur evenredige en dus rechtlijnige verbanden met afbuigingen naar rechts voor responses tot te hogere doses. De afwijkingen van rechtlijnigheid kunnen hier worden toegeschreven aan een beperkt aantal vermeerderingsloci of aan antagonisme tussen de cellen van het pathogeen.Geen essentieel verschil in dosis-respons verhoudingen werd gevonden tussen homologen en heterologe waardplant-pathogeen combinaties.De implicaties van bovengenoemde resultaten voor de kwantitatieve studie van factoren die de vatbaarheid van planten voor infectie door bacteriën bepalen, worden besproken.     

Trafficking of molecules between parasitic plants and their hosts

Parasitic plants have evolved various methods of invading host plants. Some invade aerial parts, whereas others invade the roots to obtain necessary nutrients for their development. Phelipanche and Orobanche spp. (broomrapes) and Cuscuta spp. (dodders) are holoparasitic plants that subsist on roots and shoots, respectively, of a variety of agricultural crops. These weeds are able to connect directly with the vascular system of the host, thereby acquiring the water, minerals and carbohydrates necessary for their own growth and reproduction. This exploitation by parasitic plants often causes severe losses in yield quality and quantity of host crops. The key to an effective means for controlling parasitic plants lies in the development of resistant crops, supported by an improved understanding of broomrape and dodder biology. The haustoria formed at the junctions of parasite and host open the way for translocation of a variety of molecules and macromolecules from the host to the parasite. At the same time, however, the haustoria also open opportunities for the development of methods to control parasitic plants. This review will summarise the current knowledge on translocation of siRNAs, mRNAs, viruses, sugars, proteins and herbicides from host to parasitic plants and the potential significance of such molecules to the parasite. Improved understanding of the molecular exchange between host plants and their parasites is expected to lead to the development of state‐of‐the‐art, effective approaches to parasitic weed management.     

Seasonal abundance of sap beetles (Coleoptera: Nitidulidae) in date plantations in Israel

Seasonal abundance of nitidulid beetles infesting date plantations in Israel was studied through captures of adults in traps.Carpophilus mutilatus andC. hemipterus were found throughout autumn, winter and spring; in the summer their populations declined considerably.Urophorus humeralis predominated during the summer whileHaptoncus luteolus was most abundant during late summer and autumn. Damage to ripening fruit by sap beetles is apparently inflicted mainly byH. luteolus andU. humeralis.     

Ground-active arthropod response to distance from the Mediterranean seashore in coastal sand areas of western Israel

Information on the effects of distance from the seashore on soil biotic communities is limited and restricted to soil arthropods and microarthropods. The aim of this study, conducted in a sand-dune area, was to distinguish the changes of a ground-active arthropod community along a 4-km-transect from the seashore going inland. Pitfall traps were set up in open spaces at four locations (L1, through L2, L3, and L4 going inland) through the year. The abiotic gradient from the seashore going inland was found to be mostly dependent on seasonality. Group richness was found to be remarkably greater at the L2, L3, and L4 locations compared with the L1 location in winter, and at the L2 and L3 locations compared with the L1 location in spring. The Fisher α index was 0.32?±?0.21, 3.51?±?0.87, 5.04?±?0.70, and 4.86?±?0.54 in winter and 3.29?±?0.55, 13.79?±?1.49, 10.12?±?1.24, and 5.06?±?0.62 in spring at the L1, L2, L3, and L4 locations, respectively. Regarding abundance and group richness, the trophic relationships between predators, phytophages, omnivores, and saprophages were remarkably affected by both location and seasonality. The dominant groups and dominant index distribution of ground-active arthropod communities were found to follow a similar pattern. Soil organic carbon content was found to be the key factor driving the ground-active arthropod community structure along a coastal gradient going inland in winter and spring. We conclude that the distribution, trophic composition, and diversity index are affected by both location and seasonality, while total abundance is consistently affected by location across all three seasons.     

The natural occurrence of bean yellow mosaic, cucumber mosaic and tobacco mosaic viruses in lisianthus in Israel

Mosaic on leaves, necrosis, stunting and flower symptoms were observed in lisianthus ( Eustoma russellianum ) raised from seed. Three viruses, bean yellow mosaic (BYMV), cucumber mosaic (CMV) and tobacco mosaic (TMV), were isolated. Virus identification was based on electron microscopy, host range, aphid transmission and serology.     

Seasonal development of the eucalypt borer,Phoracantha semipunctata,In Israel

Observations on the seasonal development ofPhoracantha semipunctata (Fab.) (Coleopteia: Cerambycidae), the eucalypt borer, were carried out in 11 plantations ofEucalyptus camaldulensis Dehn. and two ofE. gomphocephala DC, situated in areas from Qiryat Shemona (Upper Galilee) to Ze’elim (western Negev), using trap logs. Egg masses of the borer were usually found during the warm season but also in small numbers during the winter. Larvae which hatched during the colder season generally died, due to the relatively accelerated drying of the bark. Mean minimum duration of development from egg laying to the onset of adult emergence wasca 100 days for individuals which began to develop between spring and mid-summer (March to July);ca 215 days for the late summer brood (August to September); andca 195 days for the autumn brood (October to November). Mean larval development comprised about 66%, 64%, 36% and 81% of the total development period in spring, early and mid-summer, late summer, and autumn, respectively. Mean spring development of the larvae lasted 70 days in fresh materialvs 118 days in old (partly dry) material. The pupation period lasted between 32 and 40 days when it began between spring and late summer, andca 110 days when it started in the autumn. When adult emergence began between spring and mid-summer it was usually completed within 2–3 months, whereas when starting from late summer onward it lasted up to 9 months. Emergence was arrested during the winter and resumed with a rise of temperature in the spring. The borer develops two or three annual generations, depending upon the area.     

Co-evolution of potato cyst nematodes and their hosts: implications for pathotypes and resistance1

The co-evolutionary process is believed to have resulted, through interaction of wild populations of potato cyst nematodes and their hosts in geological time, in the resistant hosts now utilized in plant breeding programmes and in nematode populations with genes for resistance-breaking or virulence. It is argued that all such interactions between highly adapted, truly parasitic plant nematodes and their hosts are likely to be governed by gene-for-gene interrelationships. Practical implications of this hypothesis are that only pathotypes (resistance-breaking races) defined against identified resistance genes are scientifically sound and of practical value; that, in the case of potato cyst nematodes, other pathotypes (Ro2, Ro3, Ro5 and Pa2 and Pa3) should be abandoned; and that oligogenically based resistance to potato cyst nematodes, especially important in providing resistance to Globodera pallida, is non-durable. Working definitions of the terms ‘pathotype’, ‘host-race’ and ‘virulence’ are provided.     

Comparison of the seasonal occurrence and behavior of seven pine bark beetles (Coleoptera: scolytidae) in Israel

The seasonal occurrence, behavior and gallery system of seven sympatric pine bark beetles were examined at two sites, using trap-logs and trap-trees ofPinus halepensis. Two groups of beetles were recognized:(a) Tomicus destruens, Hylurgus micklitzi andHylastes linearis, which are monogamous, univoltine, breed during the winter and early spring, and prefer the lower section of the tree;H. micklitzi andH. linearis tend to infest the main root system,(b) Orthotomicus erosus, Pityogenes calcaratus, Carphoborus minimus andCrypturgus mediterraneus, which are polygamous, multivoltine, and breed from spring to autumn.O. erosus usually infests the lower stem sections,P. calcaratus occupies the thin smooth bark aboveO. erosus, andC. minimus develops on the top stem.Cr. mediterraneus lives in the mines and egg tunnels of the other species and uses their gallery entrance holes. Occupation of different stem sections by the beetles, and beetle damage as related to tree age are discussed.     

我国水体中持久性有机污染物的分布及其对鱼类的风险综述

持久性有机污染物(POPs)具有高毒、持久、生物累积、远距离迁移等特性,严重威胁环境生物和人类健康。水体是POPs在环境中迁移转化的重要介质,其在水体中可通过迁移、吸附、沉降等作用及食物链对不同种类水生生物的生长、发育及生殖产生影响。作者整理了近年来我国学者对水域中POPs的监测结果,就此类化合物在我国水体中的分布情况进行了综述。鱼类作为地表水生态系统中最主要的脊椎动物,具有重要的环境指示作用。本文通过对POPs对鱼类毒性数据的分析,评价了我国主要水域中POPs对鱼类的危害,旨在为揭示此类化合物的水生生态风险提供参考。