Central Coastal Plain Of Israel Research Articles

Late Acheulian Jaljulia - Early human occupations in the paleo-landscape of the central coastal plain of Israel.

The Lower Paleolithic Late Acheulian in the Levant marks a fascinating chapter in human cultural and biological evolution. Nevertheless, many aspects of the Late Acheulian are still undeciphered, hindered by the complex nature of each site on the one hand, a scarcity of wide, multidisciplinary studies on the other, and by difficulties in obtaining absolute chronology for this timeframe. Therefore, subjects such as human subsistence strategies and modes of adaptation, regional diversity, and the possible existence and nature of interactions between hominin groups are largely understudied. The discovery and study of Jaljulia, a large-scale Late Acheulian site at the central Coastal Plain, Israel, add valuable insights to the research of this chapter in human history. Considered to represent recurrent occupations at a favored, water and flint-rich setting, the site has provided extensive lithic assemblages obtained from several localities. Absolute chronology places the human activity on-site at roughly 500-300 ky (and possibly even later), which is suggested to be divided into several main occupation phases. Geomorphological and sedimentological analyses show a change in environmental conditions, from aeolian sand deposition and overlying Hamra soil during the Middle Pleistocene to high energy fluvial regime which transported large gravels in a north-south paleo-channel. Wetland environments, correlating to the human activity on site, developed later due to higher sea levels and a coastline shifts to the eastward, which caused a blockage of the Yarkon stream corridor to the sea by marine sand. In this paper we present results of the study of the site, including geomorphological formation and post-depositional processes, absolute chronology, lithic and faunal analyses. The site's extensive lithic assemblages are currently under study and future investigations are expected to shed more light on the technological nature of Late Acheulian Jaljulia.

The charcoal assemblage from Nesher Ramla, Israel: A contribution to the paleo-environmental dataset from Marine Isotope Stage (MIS) 5 in the Levant

This paper presents the results of the wood charcoal analyses from the Middle Paleolithic open-air site at Nesher Ramla, on the central coastal plain of Israel. The study focuses on the interpretation of the charcoals left by fires used by Middle Paleolithic hominins during early Marine Isotope Stage (MIS) 5. Moreover, this study sheds light on the arboreal taxa present in the vegetation and environmental conditions in the southern Levant during the Middle Paleolithic. A small quantity of identifiable charcoals was retrieved from the 8-m-thick archaeological sequence of the site (Units II to VI). The largest charcoal assemblage was recovered from part of the sequence dated to MIS 5e. The results show the presence of deciduous Quercus sp. and Prunus. The presence of these taxa, together with other proxies from the multidisciplinary studies at Nesher Ramla, indicate an arboreal setting with relatively humid and mild climatic conditions in MIS 5e. Our results further suggest that wood was used as fuel at Nesher Ramla. Given the scarcity of Middle Paleolithic sites in the Levant that have yielded charcoal, this new data from Nesher Ramla constitutes an important contribution to the study of past environments and the exploitation of plant resources by human groups.

Anthropogenic overprints on natural coastal aeolian sediments: A study from the periphery of ancient Caesarea, Israel

Abstract Near surface sediment stratigraphy associated with ancient human settlements can potentially reveal the complex history of human impact. This study explores such impacts in the area around ancient Caesarea, a well-known Roman to Early Islam period metropolis in the central coastal plain of Israel, with analysis of human-induced macro-features and microscopic remains found in buried sediments. We retrieved these anthropogenic markers through boreholes and analysed them with sedimentological and radiometric dating techniques, integrated with archaeological and historical records. The analysis identified a refuse deposit comprising two grey loamy sand artefact-bearing facies bedded between late Holocene aeolian sand. One anthropogenic facies represents an urban garbage mound and the other may be an agricultural pedo - sediment, both dated to the Roman to Early Islamic periods. The grey pedo-sediment, contained in three boreholes in the lowlands south of Caesarea, covers an area of at least 1.4 km 2 . Apparently improved in terms of soil fertility, we postulate that the pedo-sediment is the outcome of composting enrichment of the soil for agriculture. Taking advantage of the high coastal freshwater aquifer in the study area, we propose that the pedo-sediment represents buried agricultural plots. The comprehensive, multi-disciplinary approach demonstrated in this study of cored sediments outside ancient human settlements is among the few in the coastal area of the southern Levant. It could be relevant to other archaeological sites in the Mediterranean and elsewhere around the world.

A Roman pottery kiln at Khirbet ‘Azzun (Ra‘anana), Israel

This paper focuses on a 3rd–4th century AD pottery kiln from Khirbet ‘Azzun (Ra‘anana), in the Sharon, in the central coastal plain of Israel. The kiln belongs to the updraft type, with an oval-shaped and crater-like firebox, a fuel opening on the north and spanned by brick arches designed to support the floor of the missing ware chamber. Like many other kilns in that region, it produced storage jars. Our kiln is the first from the region dating to the Roman period, to be fully studied. The kiln’s components, technology and supposed process of operation will be examined closely, in light of other kilns from Roman-Byzantine Palestine and ethnoarchaeological evidence.

Archeometallurgical characterization of Late Roman- and Byzantine-period Samaritan magical objects and jewelry made of copper alloys

Characterization of eleven copper alloy artifacts, dated between the 4th and 6th (or early 7th) centuries AD, retrieved from archeological excavations of remains associated with Samaritan sites along the central Coastal Plain of Israel, was performed. The assemblage includes three inscribed polygonal finger rings, four finger rings with decorated bezel (of which one bears a legend in the Samaritan script), two inscribed amulet pendants, and two thin cylindrical foils (containers of phylacteries, designated for the safekeeping of a magical or religious text written on papyri or parchment). The aim of this research is to use archeometallurgical non-destructive and destructive methods in order to determine manufacturing processes of the objects, and if possible their production place, their origin of ore and their use.The results indicate that the three polygonal rings were prestige objects made of gunmetal and manufactured by lost-wax casting followed by heat-treatment probably at the same workshop. Among the four finger rings with decorated bezel, the two with incised motifs were made of gunmetal alloy, while the one with eye-shaped bezel was made of relatively pure leaded-copper, and the other ring, with the inscribed bezel, was made of brass. These rings were manufactured by using dissimilar techniques; the two with decorated bezel by casting and then shaped by hammering and annealing cycles; the eye-shaped bezel ring by casting with no further treatment; and the inscribed bezel ring made of brass by manufacturing two different parts, hoop and bezel, that were brazed together, and then hammered and annealed.Both amulet pendants were manufactured by lost-wax casting and given their shape and composition they were probably manufactured at two different workshops.Both cylindrical foils were made of leaded-copper that was first cast into an open mold, then hammered into a thin foil and folded at a later stage, probably at the same workshop.All the examined gunmetal and brass artifacts contained 4–20wt.% Zn, indicating that their alloys were originally manufactured by cementation, produced of recycled metal, probably due to economic considerations. The present study indicates the existence of a limited number of local metal workshops which specialized in the manufacture of copper alloy jewelries and related objects; some were apparently operated by Samaritans.

CONTRIBUTION TO THE KNOWLEDGE OF THE BIOLOGY OF THE BANDED NEWT (TRITURUS VITTATUS VITTATUS) IN RAINPOOLS IN ISRAEL

ABSTRACT The period of activity, population parameters and food habits of adult Triturus v. vittatus were studied in a small rainpool system, in the central coastal plain of Israel. During November-December adults occurred on land. Thereafter, until the end of February, they occurred mostly in water. Breeding took place in February. The newts disappeared from the area of the pools by the end of February. The period of activity in and around the pools was shorter by 2–4 months than that reported for a northern population. On land as well as in water the highest proportion of newts were found when the ambient midday temperature ranged from 17° to 21°C. The observed population comprised more males than females. Males were significantly longer than females. Adult T. v. vittatus feed on a wide range of terrestrial and aquatic invertebrates but may exhibit some degree of food selection.

Toposequence of sandy soils in the northern coastal plain of Israel: Polygenesis and complexity of pedogeomorphic development

Catenary relationships of surface soils in the vicinity of kibbutz Shomrat in the Galilee coastal plain of Israel were studied including optically stimulated luminescence (OSL). The research provides new insights into the local pedogeomorphic history and confirms that the study area is of different age than the central coastal plain of Israel. The soil toposequence is composed of polygenic red Hamra (Rhodoxeralf) on the hilltop, a calcareous Rhodoxeralf (Husmas) on the middle slope, both older than 250ka, and a complex pedosedimentary sequence in a lower position spanning Middle Pleistocene–Holocene OSL ages. The hilltop red Hamra is strongly reworked by soil burrowing animals, magnetically enhanced, and contains aged clay coatings and a few petrocalcic nodules. Micromorphology revealed a relict nature of cemented carbonate nodules and allowed us to establish a sequence of pedogenic episodes, e.g. rubification and clay illuviation that intermittently affected nodule growth and re-crystallization. All soils are dominated by interstratified illite–smectite, whose amount and expandability increase downhill. In the lowest topographic positions, soil development was compounded by additional fine-grained accumulation via eolian and slope processes which may have intensified during periods of geomorphic instability. Our data and interpretations suggest that to the north of Haifa Bay, coastal geomorphic surfaces are formed by late Mid-Pleistocene exhumed paleosol toposequences, which are sporadically overprinted by younger paleosols, and continue to function as presently active soils.

The roles of water vapour, rainfall and solar radiation in determining air temperature change measured at Bet Dagan, Israel between 1964 and 2010

Monthly mean values of climate at Bet Dagan in the central coastal plain of Israel, downwind of Tel Aviv, were analysed to yield seasonal and annual values of long- and short-wave irradiance which were then related to changes in air temperature measured between 1964 and 2010. Over half the large interannual variation and significant increase in atmospheric long-wave radiation, which averaged 0.7 W m−2 per decade, was associated with concurrent changes measured in specific humidity. The remaining changes were attributed to increases in concentrations of carbon dioxide and other anthropogenic radiatively active gases. Large decadal variations and a significant overall reduction in short-wave solar radiation were measured averaging 3.6 W m−2 per decade which were, in part, attributed to urban pollution. Changes in downwelling long- and short-wave irradiances together accounted for 58% of interannual variation in the mean annual temperature. Climate sensitivity to short-wave radiation forcing was very low compared with that of long-wave forcing resolving the paradox of the sharp rise in temperature accompanying negative all-wave radiative forcing (RF). Possible physical mechanisms explaining the decoupling between annual values of solar irradiance and air temperature are discussed. A significant, inverse correlation between temperature and the annual number of rain days was found, accounting for 21% of the interannual variation in air temperature unexplained by surface RF. During the last 45 years, changes in annual temperature at Bet Dagan, a near-coastal site with a strong urban influence situated in the semi-arid Mediterranean climate, were associated, in the following order of importance, with changes in water vapour, rainfall and solar radiation. Copyright © 2012 Royal Meteorological Society

Predation of amphibians by carabid beetles of the genus Epomis found in the central coastal plain of Israel

The genus Epomis is represented in Israel by two species: Epomis dejeani and Epomis circumscriptus. In the central coastal plain these species are sympatric but do not occur in the same sites. The objective of this study was to record and describe trophic interactions between the adult beetles and amphibian species occurring in the central coastal plain of Israel. Day and night surveys at three sites, as well as controlled laboratory experiments were conducted for studying beetle-amphibian trophic interaction. In the field we recorded three cases of Epomis dejeani preying upon amphibian metamorphs and also found that Epomis adults share shelters with amphibians. Laboratory experiments supported the observations that both Epomis species can prey on amphibians. Predation of the three anuran species (Bufo viridis, Hyla savignyi and Rana bedriagae) and two urodele species (Triturus vittatus and Salamandra salamandra infraimmaculata) is described. Only Epomis dejeani consumed Triturus vittatus. Therefore, we conclude that the two species display a partial overlap in food habit.

Onset of a pandemic: characterizing the initial phase of the swine flu (H1N1) epidemic in Israel

BackgroundThe swine influenza H1N1 first identified in Mexico, spread rapidly across the globe and is considered the fastest moving pandemic in history. The early phase of an outbreak, in which data is relatively scarce, presents scientific challenges on key issues such as: scale, severity and immunity which are fundamental for establishing sound and rapid policy schemes. Our analysis of an Israeli dataset aims at understanding the spatio-temporal dynamics of H1N1 in its initial phase.MethodsWe constructed and analyzed a unique dataset from Israel on all confirmed cases (between April 26 to July 7, 2009), representing most swine flu cases in this period. We estimated and characterized fundamental epidemiological features of the pandemic in Israel (e.g. effective reproductive number, age-class distribution, at-risk social groups, infections between sexes, and spatial dynamics). Contact data collected during this stage was used to estimate the generation time distribution of the pandemic.ResultsWe found a low effective reproductive number (Re = 1.06), an age-class distribution of infected individuals (skewed towards ages 18-25), at-risk social groups (soldiers and ultra Orthodox Jews), and significant differences in infections between sexes (skewed towards males). In terms of spatial dynamics, the pandemic spread from the central coastal plain of Israel to other regions, with higher infection rates in more densely populated sub-districts with higher income households.ConclusionsAnalysis of high quality data holds much promise in reducing uncertainty regarding fundamental aspects of the initial phase of an outbreak (e.g. the effective reproductive number Re, age-class distribution, at-risk social groups). The formulation for determining the effective reproductive number Re used here has many advantages for studying the initial phase of the outbreak since it neither assumes exponential growth of infectives and is independent of the reporting rate. The finding of a low Re (close to unity threshold), combined with identification of social groups with high transmission rates would have enabled the containment of swine flu during the summer in Israel. Our unique use of contact data provided new insights into the differential dynamics of influenza in different ages and sexes, and should be promoted in future epidemiological studies. Thus our work highlights the importance of conducting a comprehensive study of the initial stage of a pandemic in real time.

An objective and automatic method for identification of pattern changes in wind direction time series

AbstractFinding the point in time at which the wind pattern changes its direction is an important problem with a broad scope of application in atmospheric boundary layer modelling. In many cases such a change of pattern can be extracted using subjective methods, which involves a subjective post analysis of the measured time series. A considerably more difficult task is identifying such a change using an objective and automated method. This task is usually treated by smoothing the original time series, extracting threshold parameters using a statistical analysis of the past wind data, and setting threshold values via trial and error. We present here an objective and automatic method for solving this problem. The method identifies extrema and bending points in the cumulative sum terms of sine and cosine of the wind direction time series, which are based on the directional cumulative sum principle. Our method is non‐parametric, and needs neither prior calibration of threshold values nor smoothing of the data. Furthermore, our method is unique in its ability to detect the pattern change even if the direction change occurs gradually. An example of the application of the method is presented using 6 months of data collected at a single meteorological station located on the central coastal plain of Israel. The method was applied to identify the timing of the occurrence of the nocturnal land wind period (beginning and end). Out of 176 days examined, the method identified correctly more than 90% of the periods. Copyright © 2010 Royal Meteorological Society

Decline of wetland ecosystems in the coastal plain of Israel during the 20th century: Implications for wetland conservation and management

Severe competition for water and augmented agricultural and urban development in Israel have modified and destroyed wetland habitats. Using historical maps, we mapped the past extent of swamps and natural rain pools along the central coastal plain of Israel and compared this with the present extent as reflected in reports, field surveys and satellite images. Out of 192 swamps and rain pools recorded in historical sources, only 18% (35) still exist today. Extrapolation from 69 new records of rain pools (missing in historical sources), suggests that in the 19th century, before many of the wetlands were drained, transformed to agricultural land, or built over, the number of wetland habitats in the coastal plain was threefold higher. In addition to reduction of wetland number, human activity has also diminished wetland size. In rainy winters wetland areas in the coastal plain in the past were an order of magnitude larger than they are today (27.6 and 2.4 km 2, respectively). At present, the existing natural water bodies along the coastal plain are temporary, small, and surrounded by built-up areas and roads. The grave state of the wetlands in Israel underscores the urgent need for protection of the remnant wetland sites. Following the successful example of wetland restoration in the Hula Valley, we recommend restoring various historical wetlands that have been drained.

Wood remains from archaeological excavations: A review with a Near Eastern perspective

In this review I describe and discuss the technical issues of identification of archaeo logical wood remains from archaeological excavations and the types of data that can emerge from studying them. I discuss uses of wood; types of wood remains (dry, charred, waterlogged, sub-fossil, fossilized); crystals from wood; the anatomical basis for wood identification, including the different anatomies of conifers, mono cotyledons, and dicotyledons; regular and traumatic tissues; endogenous trends of anatomical changes related to age, size, and position within the plant; and damage by fungi and insects and their identification. Wood preservation, common micro scopic methods for wood identification, wood anatomical atlases for the Levant and other relevant regions, and the lack of bark descriptions are all discussed. Wood fiber identification, statistical characters of wood anatomy, dendrochronology (tree-ring studies), and the use of stable and radioactive isotopes from wood continue. Possibilities of identification of the origin of wood by Strontium and ancient DNA and other molecular studies follow later in the review. The role of floral data emerging from studies of archaeological wood remains in planning current forests and nature conservation is discussed. In this context, an example is given of the role of wood remains in understanding the dominance of Quercus calliprinos (kermes oak) in the Central Coastal Plain of Israel. Geobotany and the question of identifying climatic changes, social status as reflected in the types of wood used in Masada (King Herod’s palace versus Roman siege rampart), wood as an indication of ancient trade, and wood as reflecting horticulture are also discussed. Woodworking technology, the use of fire, and dealing with multidisciplinary issues and conclusions end the review. Concerning archaeological wood remains, it is impossible to exploit all theoretical and technical abilities in all studies, and scientists involved in any archaeological project have to decide about priorities. Studying archaeological wood remains is a very complicated multidisciplinary issue. Archaeological wood identification is commonly conducted by non-botanists, who have difficulties with the botanical, ecological, and environ mental aspects, while evaluation of the identified plant material by botanists involves similar difficulties with archaeological and cultural issues. No scientist is able to master all relevant aspects, and such multidisciplinary issues usually require a wellbalanced team to deal with them.

Identification and evaluation of potential predators of the citrus rust mite, Phyllocoptruta oleivora, in Israel

Damage caused by citrus rust mite (CRM), Phyllocoptruta oleivora (Ashmead), is usually negligible in minimally to unsprayed isolated groves located in the central coastal plain of Israel. Assuming that resident natural enemies were responsible for this situation, we monitored the pest’s potential predators in five unsprayed citrus plots, and concurrently determined their feeding habits in the laboratory. In the field Iphiseius degenerans (Berlese) and Amblyseius swirskii Athias-Henriot were the main predators found, the former being dominant during the critical winter and spring months, the period of low pest populations. In the laboratory, when solely CRM was offered, the decline in pest numbers was similar in leaf arenas containing either phytoseiid or the stigmaeid Agistemus cypriusGonzalez. Only I. degenerans, however, seemed to kill fewer CRM in the presence of pollen. While the cessation of pesticide applications during two years was insufficient for reducing CRM populations, observations suggest that a three year break from broad spectrum pesticides would be the turning point for the reestablishment of I. degenerans, the postulated more important predator. Our field and laboratory data suggest that a complex of indigenous, generalist predators could be responsible for the control of CRM in isolated, unsprayed citrus groves on the central coastal plain of Israel.

Conservation of the critically endangered Rumex rothschildianus as implied from AFLP diversity

Rumex rothschildianus (Polygonaceae) is a small dioecious annual endemic to the central coastal plain of Israel. This very rare sorrel is on the verge of global extinction, as its total gene pool consists of two surviving populations only: one small and the other relatively large and flourishing. The other ten populations of this species recorded during the 20th century (all in Israel) are now extinct. Amplified fragment length polymorphism (AFLP) markers were used to evaluate the population genetic structure of the two remaining populations. Genetic diversity in R. rothschildianus was H=0.17 with 48.9% polymorphic loci. Gene flow values suggest that the differentiation between the two populations is moderate (mean F st=0.09). Considering these genetic data, two conservation management strategies should be applied: (1) Large scale reseeding in a neighbouring nature reserve to maintain the genetic diversity detected in this study. Seeds from diverse sources should be used for repeated reseedings in order to prevent the reintroduced populations from going through a genetic bottleneck or suffering genetic drift. (2) To maintain the genetic diversity in the two remaining wild populations, and to avoid risks such as possible outbreeding depression, only intrapopulation reinforcement should be considered. These populations should be carefully monitored and protected.

Testing the use of multivariate inter-site taphonomic comparisons: the faunal analysis of Hefzibah in its Epipalaeolithic cultural context

The results of a detailed zooarchaeological and taphonomic analysis of two faunal assemblages from Hefzibah (HEF), a major Geometric Kebaran open-air site on the central coastal plain of Israel were compared with two other assemblages from the same general period, site type, and geographic region using multivariate taphonomic analyses. A comprehensive analysis of taphonomic evidence for each assemblage based on the comparison of 28 taphonomic variables points to a preservational bias that accounts for the apparent economic differences found in one of the four Epipalaeolithic assemblages. Preservational indices, surface modification, bone density, and bone fragmentation indicate that inter-assemblage differences are related to post-depositional processes. These processes account for marked differences in species diversity, the percentage of juveniles, and the proportion of small game. The marked difference in preservation highlights the potential role of taphonomic biases in producing overt patterns that bear no real cultural or economic significance in zooarchaeological assemblages. High similarity in the length of fresh percussion fractures, the ratio and distribution of butchery marks, and prey body part representation suggest analogous traditions of food transport, preparation, and processing.

Spatial and Structural Variation of the Atmospheric Boundary Layer during Summer in Israel—Profiler and Rawinsonde Measurements

Abstract An opportunity to improve understanding related to the structure of the atmospheric boundary layer (ABL) in Israel along the coastal region environs emerged in April 1997 when the Israel Electric Corporation, Ltd. (IEC), installed and began the operation of a 1290-MHz radar profiler and radio acoustic sounding system (RASS) midway between Haifa and Tel Aviv. This instrument is, in addition to the upper-air measurements carried out routinely by the Israel Meteorological Service (IMS) in Beit-Dagan, at the central coastal plain of Israel. In order to better characterize the spatial variation of the turbulent mixed layer and the stable layer capping it within the ABL, the upper-air measurements from the profiler were compared with the concurrent rawinsonde data from the permanent sounding site in Beit-Dagan. The analysis and simultaneous comparison of both instruments was done for noontime of two consecutive summers (1997–98) and included the following ABL parameters: depth and lapse rate of the mix...

Geological and pedological aspects of an Early-Paleolithic site: Revadim, Central Coastal Plain, Israel

An Early Paleolithic site was recently discovered within a sequence of paleosols in the Revadim Quarry, central coastal plain of Israel. The section is composed of three superimposed soils in a continuous sequence, but separated by two unconformity surfaces. The uppermost paleosol is a modern Dark Brown Grumusol (Vertisol), the middle is a Quartzic Gray Brown Soil (Haploxeralf), and the lower is a Red Hamra (Rhodoxeralf). Normal magnetic polarity was detected in the two lower soils, indicating that they are younger than the Brunhes–Matuyama boundary (<780 ka). A human occupation bed, enriched in secondary carbonate nodules, forms the lower part of the Quartzic Gray Brown Soil and overlies the Red Hamra. The living floor is located on top of the unconformity surface, separating the Red Hamra from the overlying Quartzic Gray Brown Soil. Middle to Late Acheulian handaxes, choppers, cores, and flake tools, including tools made by the Levallois technique, and man-laid flint pebbles were excavated in the human occupation bed. In addition, two elephant tusks, an elephant pelvis, an elephant tooth (Palaeoloxodon antiquus), tusk splinters, and bones of equid, suid, cervid, bovid, felid, and rodents were also collected. Based on well-documented nearby boreholes and on regional correlation, it appears that the underlying dune sands, the parent materials from which the Red Hamra developed, were deposited probably during a phase of high-stand sea level of Isotope Stage 9. The Red Hamra developed simultaneously with the human occupation of the site, probably during a phase of low-stand sea-level of Isotope Stage 8, before some 300–245 ka. The overlying dune sands, the parent materials from which the Quartzic Gray Brown Soil developed, were deposited probably during a phase of high-stand sea level of Isotope Stage 7. The climate prevailing in the area during Stage 8, as well as during the human habitation, was moist, with a dense vegetation cover of grassland and probably scattered trees. A small lake of trapped fresh water at a junction of two small tributaries of the Soreq River drainage system near the area occupied was available to hominids and animals. © 1999 John Wiley & Sons, Inc.

Culture of the Australian red-claw crayfish ( Cherax quadricarinatus) in Israel : III. Survival in earthen ponds under ambient winter temperatures

The survival of the tropical crayfish Cherax quadricarinatus in earthen ponds under ambient winter temperatures was studied in the temperate zone in the central coastal plain of Israel. Four treatment groups in which sex and size were each tested at two levels were simultaneously run in four replicates over a period of 118 days (28 November 1996–26 March 1997). Minimum and maximum water temperatures were monitored every day, with minimum daily temperatures of under 10°C being recorded on six days. Overall survival was 60%; neither independent nor combined effects of sex and size on survival were found to be significant. Change in weight was minimal and few crayfishes entered baited traps, probably reflecting the reduced motor activity and feeding at low water temperatures. The economic implications of crayfish survival in earthen ponds under ambient winter temperatures, as well as the potential establishment of wild populations are discussed.

Laboratory efficacy screening of insecticides for control ofMaladera matrida Larvae

Maladera matrida Argaman (Coleoptera: Scarabaeidae) was first reported in the central coastal plain of Israel in the early 1980s and was subsequently described as a new species. By the late 1980s it had spread southward to the northwestern Negev desert region, where heavy infestations of this pest caused significant economic losses, especially to growers of peanuts and sweet potatoes. Larvae (white grubs) ofM. matrida feed on underground parts of plants. We used a laboratory soil-treatment assay for determining the relative toxicity of several insecticides to 3-week-old grubs. Insecticides, both registered and candidates for registration, were tested at the labeled rates for field crops. The residual activity of those insecticides that caused ≥60% mortality of grubs after the first week, was studied for two additional weeks, by replacing the grubs with new ones each week. The granular formulation of the organophosphate insecticides terbufos, chloropyrifos, ethoprop and isazofos induced a uniform high mortality to grubs throughout the study period. Chloropyrifos and ethoprop caused >90% mortality also at one tenth of the labeled rate. Also diazinon brought about >90% mortality after the first week, but subsequently lost its activity. Imidacloprid, bendiocarb, fenitrothion, acephate, methamidophos and carbaryl provided <50% mortality during the first week.