At least five populations (stocks) of beluga whales (Delphinapterus leucas) are thought to winter in the Being Sea, including the Bristol Bay, Eastern Bering Sea (Norton Sound), Anadyr, Eastern Chukchi Sea, and Eastern Beaufort Sea (Mackenzie) populations. Belugas from each population have been tagged with satellite‐linked transmitters, allowing us to describe their winter (January–March) distribution. The objectives of this paper were to determine: (1) If each population winters in the Bering Sea, and if so, where? (2) Do populations return to the same area each year (i.e., are wintering areas traditional)? (3) To what extent do the winter ranges of different populations overlap? Tagged belugas from all five populations either remained in, or moved into, the Bering Sea and spent the winter there. Each population wintered in a different part of the Bering Sea and populations with multiple years of data (four of five) returned to the same regions in multiple years. When data were available from two populations that overlapped in the same year, they did not occupy the shared area at the same time. Although our sample sizes were small, the evidence suggests belugas from different populations have traditional winter ranges that are mostly exclusive to each population.
The Canadian Entomologist 127: 813-830 (1995) Male moths of Choristoneura occidentalis Freeman, C. biennis Freeman, C.fumiferana (Clemens), and C. orae Freeman were caught in pheromone-baited traps. Ten traps were placed at each site, five baited with an aldehyde lure and five with an acetate lure. This procedure permitted separation of species based on the specific chemical lure and also provided specimens for further study of morphological and isozyme differences. The color of the forewings, presence or absence of spicules on the aedeagus, and a specific allozyme frequency were determined on selected specimens where these characteristics were useful in separating species at a particular site. Distributions of all species were more extensive than previously known, sometimes adding hundreds of kilometres to the recorded range. Areas of sympahy were identified and the fidelity and usefulness of characteristics for separating species in areas of overlap were discussed.
The numbers of Douglas-fir tussock moths (Orgyia pseudotsugata) (Lepidoptera: Lymantriidae) caught in sticky, delta-shaped pheromone traps baited with different concentrations of synthetic lures were compared with egg-mass densities and subsequent defoliation throughout a population cycle. A lure containing 0.01% pheromone by weight in the form of a 3 × 5-mm polyvinylchloride rod provided more consistent catches than pheromone concentrations of 0.0001, 0.001, 0.1, or 1.0%. Trap saturation occurred when >40 moths per trap were caught. To achieve a standard error of 30%, 6 traps were required at each site. There was a poor correlation between numbers of moths caught and egg-mass density or defoliation estimates in the following generation, but a threshold density was found that provides a warning of an incipient outbreak. Ground surveys for egg masses are recommended to confirm suspected infestations after continuous increases in moth catches for 2 to 3 years or if an average of 25 moths or more per trap has been caught.
Investigation of the European pine shoot moth pheromone has revealed three components in addition to the previously identified E-9-dodecenyl acetate (E9-12:Ac): E-9-dodecenol, dodecyl acetate, and dodecanol. Inclusion of E-9-dodecenol makes lures more attractive to the moth than unmated females or E9-12:Ac alone. Dodecyl acetate had no apparent effect when added to this more attractive mixture whereas dodecanol had an inhibitory effect. Dodecyl acetate appeared to mask the inhibitory effect of dodecanol when 0.3% or more of the former component is present in the lure. Relative proportions of components are critical in comparative testing or monitoring populations of the moth.
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