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Can. Ent. 113: 419-426 (1981) The flight range of Culicoides variipennis was studied in a bluetongue virus enzootic area during the summer of 1977. Field-collected larvae and pupae were reared to the adult stage in a field laboratory. Approximately 82,200 flies were marked with micronized fluorescent dusts and released and 403 were recaptured in C02-baited baffle traps. The maximum distance traveled was 0.8 km by a male and 4.0 km by a female. One female was recovered on the release night 2.8 km from the release point. The mean distance traveled (MDT) was 0.8 km on the release night, 2.02 km on one night postrelease, and 2.11 km on two nights postrelease. The MDT for all flies recovered up to eight nights postrelease was 1.89 km.Based on the overall MDT of 1.89 km, the transmission of a disease agent by C. variipennis becomes theoretically possible if the host population density is greater than one per 3.57 km2. The probability of transmission can be significantly reduced if a 3.57 km2 area surrounding a single C. variipennis breeding site is treated with an effective insecticide.Le rayon d'action de Culicoides variipennis en vol a Ctt Ctudit dans un secteur enzootique du virus de la fitvre catarrhale du mouton durant 1'Ctt 1977. Des larves et pupes collectionntes sur le terrain ont Ctt tlevtes jusqu'au stade adulte dans un laboratoire de terrain. Environ 82,000 briilots ont Ctt marquts a l'aide de poussitre fluorescente microniste, et relichts, et 403 ont Ct C recapturks i l'aide de pikges i impact appitts au CO,. La distance maximum parcourue a kt6 de 0.8 km par un mlle, et 4.0 km par une femelle. Une femelle a Ctt retrouvte a 2.8 km du site de relichage, la nuit mZme du rellchage. La distance moyenne parcourue (DMP) a t t t de 0.8 km la nuit du relichage, 2.02 km la premiere nuit posttrieure au relichage, et de 2.1 1 km la deuxitme nuit. La DMP pour tous les brfilots recapturts jusqu'i 8 nuits postkrieures au relichage a kt6 de 1.89 km.Sur la base de la DMP globale de 1.89 km, la transmission du pathogene par C. variipennis est thtoriquement possible, si la densitt de population de I'h6te est suptrieure a un par 3.57 km2. La probabilitt de transmission peut stre significativement rtduite par le traitement des 3.57 km2 de surface couvrant le site de reproduction d'un seul C. variipennis i I'aide d'un insecticide efficace.

The preparation of hair for the determination of elements is a critical component of the analysis procedure. Open-beaker, closed-vessel microwave, and flowthrough microwave digestion are methods that have been used for sample preparation and are discussed. A new digestion method for use with inductively coupled plasma-mass spectrometry (ICP-MS) has been developed. The method uses 0.2 g of hair and 3 mL of concentrated nitric acid in an atmospheric pressure-low-temperature microwave digestion (APLTMD) system. This preparation method is useful in handling a large numbers of samples per day and may be adapted to hair sample weights ranging from 0.08 to 0.3 g. After digestion, samples are analyzed by ICP-MS to determine the concentration of Li, Be, B, Na, Mg, Al, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, Se, Rb, Sr, Zr, Mo, Pd, Ag, Cd, Sn, Sb, I, Cs, Ba, Pt, Au, Hg, Tl, Pb, Bi, Th, and U. Benefits of the APLTMD include reduced contamination and sample handling, and increased precision, reliability, and sample throughput.

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