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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.

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.

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.