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The larval developmental sites of Culicoides species were assessed from 1155 samples collected during the years 1969-2003. Culicoides circumscriptus was most prolific in mud with medium organic matter with proportional representation of 55.8%. Culicoides imicola breeds mainly in damp mixture of rotten, decomposed animal dung with or without some mud, with proportional representation of 97.2%. Culicoides obsoletus was found mostly in rotten banana stumps, with proportional representation of almost 100%. Culicoides puncticollis was found in mud with a medium amount of organic matter with proportional representation of 35.6%. Culicoides distinctipennis showed 22.2% proportional representation for mud poor in organic matter. Culicoides schultzei gr. was most prolifically in mud rich in organic matter with proportional representation of 6.2%. Culicoides cataneii was most prolifically in mud with a medium amount of organic matter with proportional representation of 1.8%. Maximum duration time to emergence from the larval developmental sites ranged from seven weeks in C. obsoletus to fourteen weeks in C. circumscriptus and nine weeks in C. imicola. All the studied species breed throughout the year. Significant innate differences in the proportions of the sexes were found in the emergence of six species.

Host preference determines which host will be bitten and therefore potentially be infected with vectored pathogenic microorganisms by hematophagous arthropods such as Culicoides. In Israel, the feeding behavior of 8 out of 60 Culicoides species was confirmed by using the precipitin tests. In the present study several morphometric parameters, which characterize bird and mammal feeders were used. By means of the number of antennomer bearing sensilla coeloconica, the following fourteen probable mammal feeders could be detected: Culicoides derisor, Culicoides fagineus, Culicoides fascipennis, Culicoides imicola, Culicoides montanus, Culicoides newsteadi, Culicoides obsoletus, Culicoides pulicaris, Culicoides punctatus, Culicoides puncticollis, Culicoides schultzei group, Culicoides shaklawensis, Culicoides pallidicornis, and Culicoides vitreipennis. In addition, the following eighteen probable bird feeders were identified: Culicoides begueti, Culicoides brunnicans, Culicoides cataneii, Culicoides circumscriptus, Culicoides kibunensis, Culicoides distinctipennis, Culicoides gejgelensis, Culicoides haranti, Culicoides indistinctus, Culicoides odiatus, Culicoides maritimus, Culicoides festivipennis, Culicoides pseudopallidus, Culicoides griseidorsum, Culicoides sejfadinei, Culicoides simulator and Culicoides univittatus. The probable bird feeders possessed a significantly larger third palpal segment. The values of the antennal ratio in probable feeders on birds were significantly higher than those in probable mammal feeders. The number of bulb-shaped sensilla in the pit of the third palpal segment was found unreliable for determining host groups.

The method of segregating nulliparous and parous females of Culicoides spp. based on the presence of burgundy-red pigment inside the abdominal wall of parous Culicoides midges, is used worldwide. Out of 320 females of Culicoides imicola trapped by emergence traps, set over an artificial breeding site for 10 and 24 days, 73 (22.8%) showed a red-pigmentation despite the fact that they were nulliparous. This finding indicated that 23% of the "parous" females that are examined for the presence of arboviruses and other pathogens or for age-grading purposes, are actually old nulliparous females, which had no chance of acquiring pathogens. This bias in parous rate distorts upward the calculation of vectorial capacity.

Culicoides oxystoma (Diptera: Ceratopogonidae) is an important vector species, reported mainly from Asia, with high potential to transmit viral diseases affecting livestock. In Japan, many arboviruses have been isolated from C. oxystoma, suggesting it as a key player in the epidemiology of several Culicoides-borne diseases. Over the years, C. oxystoma has also been reported in the Middle East region, including Israel. In this region, however, C. oxystoma cannot be easily distinguished morphologically from its sibling species included in the Culicoides schultzei complex. We therefore used genomic data for species identification and phylogeny resolution. Phylogenetic analyses based on internal transcribed spacer 1 (ITS-1) of ribosomal DNA and the mitochondrial gene encoding cytochrome oxidase subunit I (COI) showed that C. oxystoma from Israel is closely related to C. oxystoma from Japan. Using differential probing PCR, we showed that C. oxystoma is distributed all over the country, especially in Mediterranean climate regions. Culicoides oxystoma is less common or even absent in arid regions, while the other genetic cluster of C. schultzei complex was found only in the east of the country (mostly arid and semiarid regions). The molecular finding of C. oxystoma in wide geographical regions, together with its high proportion in the general Culicoides population and its vectoring potential, imply that it may be an important vector species in the Middle East.

Outbreaks of bovine ephemeral fever (BEF) occurred in Israel in 1990, 1999, and 2004. The main patterns of BEF spread were similar in the 1990 and in 1999 epidemics, and the BEF virus was probably carried in vectors transported by air streams across the Rift Valley and the Red Sea. In the 2004 outbreak, the primary focus of the disease was the southern Mediterranean coastal plain and the disease agent was apparently brought by infected mosquitoes carried from their breeding site in the Nile Delta by the south-western winds. The disease broke out under optimal ecological conditions, among a vulnerable cattle population and spread rapidly; it showed essentially a spring-summer herd incidence and terminated soon after the night average ambient temperature fell below in late autumn. The herd incidence of the disease reached 78.4%, 97.7%, and 100% in 1990, 1999, and 2004, respectively. The highest herd incidence, morbidity, and case fatality rates were noted in dairy cattle herds in the Jordan Valley, with morbidity of 20%, 38.6%, and 22.2%, and case fatality rate among affected animals of 2%, 8.6%, and 5.4% in 1990, 1999, and 2004, respectively. The average sero-positivity to BEF in 1999 was 39.5%, which matched the morbidity rate. Comparison among the various age groups showed that the lowest morbidity rates were observed in the youngest age group, that is, heifers up to 1 year, with 3.2%, 3.6%, and 4.2% in 1990, 1999, and 2004, respectively. In heifers from 1 year to calving, the morbidity rates were 13.8%, 14.9%, and 28%, respectively, in first calvers 30.8%, 31.6%, and 28.3%, respectively, and in cows 34.3%, 35.7%, and 27.2%, respectively. All affected cattle were over the age of 3 months. It is hypothesized that mosquitoes and notCulicoidesspp. are the vectors of the BEF virus in Israel.

Winds may play a major role in spread of arthropod-borne viruses (arboviruses). Arboviruses like epizootic hemorrhagic disease virus (EHDV), bluetongue virus and bovine ephemeral fever virus (BEFV) frequently cause major outbreaks in Israel with a unique pattern of spread. Most of these outbreaks begin in the Jordan valley, near the Sea of Galilee and then spread to the north, south and west through the major valleys of Israel. The aim of this study was to describe the spread pattern in such an outbreak and to find if this pattern can be explained by winds. Herein, we compared the spread rate to each direction and used Cox proportional hazards model to test factors associated with the spread of EHDV, which emerged in diary cattle in Israel during the summer of 2006. Documented, clinical and serological data on spread of the outbreak were then compared with wind data collected by meteorological stations along the trail of virus spread and with modeled winds at high altitude (>500 m). The analysis revealed that both the hazard and the rate of outbreak spread to the south and to the north were significantly higher than to the west. Average rate of outbreak spread during periods in which at least 3 h of winds to spread direction were recorded was 20,880 m/week (SD = 13,230) vs. 7486 m/week (SD = 4936) in periods during which no such winds were recorded. Serological evidence demonstrated exposure to the virus up to 166 km away from the location of the initial outbreak center. Modeled wind data showed that this spread may be explained by winds at high altitudes. Animal movements due to shipments of feedlot calves and slaughters could not explain the spread pattern observed during the outbreak. This study therefore shows that winds are probably a major contributory factor for long and medium distance spread of Culicoides borne viruses in this region.

This report describes the first molecular characterization of Akabane virus (AKAV) in Israel. The virus was recognized by real-time RT-PCR in extracts from Culicoides imicola insects trapped at the Volcani Center located in the center of Israel. This is also the first report on the use of real-time RT-PCR to identify the virus. The quantitative capability of this technique was applied, and it was calculated that the insect extract contains 1.5 x 10(5) copies of the genome segment S. Following amplification of the small (S) genome segment, its nucleotide sequence was determined to have 93.4% identity or greater with the S segment of other AKAV isolates. The deduced amino acid (aa) sequence of the combined nucleocapsid and the non-structural protein showed more than 96.6% identity. Phylogentic trees constructed using the combined deduced nucleocapsid and the non-structural protein aa sequences showed that the Israeli isolate forms a fourth cluster of AKAV, indicating a separate virus lineage. Attempts to isolate the virus by inoculation to Vero cells and by intracerebral inoculation to mice were unsuccessful.

Injuries caused by the German yellow jacket Vespula germanica F. to dry and lactating dairy cows (Bos tourus) in 5 herds in Israel were monitored and adversely affected < or = 65% of the cows. Elimination of large alternative protein sources (placentas, sewage containing milk from the milking parlor), and prebaiting with high-quality minced meat (or fish) in adequate numbers of baiting cages around the dairy farm for several days, are necessary for successful control. Significant control was achieved after a shorter period of time when the dairy farm was surrounded by a smaller area of uncultivated land than by a larger area. At some dairy farms there were significant differences among numbers of wasps visiting the various cage sites and significant variability between baiting days. Efficient and significant control was achieved by minced meat bait containing 1.5% acephate (orthene) and 2% microencapsulated diazinon (Antikan). Wasps were totally repelled by minced meat bait containing 2.25% of a plant-derived bioinsecticide derived from Meliaceae (Ag1000). The potential of using Ag 1000 for repelling yellow jackets from teats and udders of dairy cows is discussed.

Vertical suction light trapping was conducted in 1981 at two dairy farms, Bet Dagan (traps at 1.4 and 26 m above ground) and Bet Alfa (traps at 1.5 and 20 m). Of the nine Culicoides species caught in both localities, only C. circumscriptus Kieffer and C. cataneii Clastrier showed a significant difference in abundance related to trap height; C. imicola Kieffer and C. schultzei sp. gp. also demonstrated a height preference, but catch sizes did not differ statistically. C. circumscriptus and C. cataneii, both avian feeders, and C. imicola, a mammalian feeder, were caught in greater numbers in the higher than in the lower traps. In contrast, more C. schultzei sp. gp. females were caught in lower than higher traps. Species collected more frequently in higher traps may be more prone to carriage for long distances by air currents and therefore are more likely to be important as dispersal vectors.

Host preferences of mosquitoes, mainly Culex pipiens L. and Aedes caspius (Pallas), were studied in Israel using live baits, chemical attractants, light, and suction traps. The feeding habits of Cx. pipiens were opportunistic. This species used a wide range of mammalian and avian hosts; a calf, chickens, turkeys, and sheep were the most attractive baits. A. caspius fed mainly on large mammals and was most attracted to calf and sheep baits. Although sheep were attractive, few Cx. pipiens and no Ae. caspius engorged after entering the traps. In addition to defensive behavior and the mechanical protection afforded by the wool, sheep may possess a close-acting repellent that deters mosquitoes from biting. CO2 was the best attractant for host-seeking Cx. pipiens and Ae. caspius, Aedes detritus (Haliday), Culiseta annulata (Schrank), Culiseta longiareolata (Macquart), and Uranotaenia unguiculata Edwards were caught in small numbers, and their bloodmeal hosts were recorded.

Fluoroacetamide (1081 or F.A.A) is used in Israel for field rodent control. Experiments on direct and secondary, short and long term poisoning caused by 1081 were carried out. Mongoose (Herpestes ichneumon), hyena (Hyaena hyaena), cats and dogs were susceptible. Barn owls (Tyto alba), buzzards (Buteo buteo) and black kites (Milvus m. migrans) were markedly resistant. Barn owls tolerated total direct poisoning ranging from 6.8 to 10.9, and a final dose ranging from 0.8 to 2.0 mg/kg. In secondary poisoning, total doses ranging from 1.7 to 7.1, and final doses ranging from 0.2 to 1.3 mg/kg were tolerated. Buzzards tolerated total direct poisoning ranging from 6 to 12.0, and final doses ranging from 0.7 to 1.3 mg/kg. In secondary poisoning, doses ranging from 0.8 to 10.3 and final doses ranging from 0.2 to 2.4 mg/kg were tolerated. One black kite tolerated a total direct dose of 6.1 and final dose of 0.7 mg/kg, another survived a total dose of 2.3 and final dose of 0.2 mg/kg in secondary poisoning. A small-scale secondary poisoning experiment on two Palestine vipers (Vipera palestinae), a Syrian black snake (Coluber jugularis) and two Montpellier snakes (Malpolon monspessulanus) indicated that these species were resistant to total doses ranging from 0.1 to 3.2 and final doses of 0.1 to 0.8 mg/kg.

The lethality of T-2 toxin to adult femaleAedes aegypti mosquitoes was investigated using various methods of application: Topically, by injection, and by natural feeding. The technique of topical application was found to be the most precise, whereby an LD50 of 565 ng T-2 toxin/mosquito was determined.

Delécolle Jean-Claude, Braverman Yehuda. Description de Serromyia mangrovi n. sp. du Sinai [Dipt. Ceratopogonidae]. In: Bulletin de la Société entomologique de France, volume 92 (1-2), novembre 1987. pp. 57-65.