New trap designs for tsetse (Glossinidae), stable flies (Muscidae: Stomoxyinae), and horse flies (Tabanidae) were tested in Kenya to develop a multipurpose trap for biting flies. Many configurations and colour/fabric combinations were compared to a simplified, blue-black triangular trap to identify features of design and materials that result in equitable catches. New designs were tested against conventional traps, with a focus on Glossina pallidipes Austen and G. longipennis Corti, Stomoxys niger Macquart, and Atylotus agrestis (Wiedemann). A simple design based on minimal blue and black rectangular panels, for attraction and contrast, with a trap body consisting of an innovative configuration of netting, proved best. This 'Nzi' trap (Swahili for fly) caught as many or significantly more tsetse and biting flies than any conventional trap. The Nzi trap represents a major improvement for Stomoxyinae, including the cosmopolitan species S. calcitrans (Linnaeus), with up to eight times the catch for key African Stomoxys spp. relative to the best trap for this group (the Vavoua). Catches of many genera of Tabanidae, including species almost never caught in traps (Philoliche Wiedemann), are excellent, and are similar to those of larger traps designed for this purpose (the Canopy). Improvements in capturing biting flies were achieved without compromising efficiency for the savannah tsetse species G. pallidipes. Catches of fusca tsetse (G. longipennis and G. brevipalpis Newstead) were higher or were the same as catches in good traps for these species (NG2G, Siamese). Altogether, the objective of developing a simple, economical trap with harmonized efficiency was achieved.

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Five blue and black cloth traps designed for tsetse were tested for their ability to catch Stomoxys spp. in Kenya. Significantly greatest catches were obtained with Vavoua traps, which then were used to compare odor baits at Nairobi Park. Acetone, lactic acid, and animal urine (cow, buffalo, waterbuck, camel) or dung (rhinoceros, elephant, hippopotamus) did not increase catches. However, 1-octen-3-ol dispensed at 0.2-2.0 mg/h increased catches up to 3.7-fold. Vavoua traps were highly specific for Stomoxyinae, with 80% of the catch consisting of 11 different taxa of Stomoxys as well as genera such as Prostomoxys, Haematobosca, Stygeromyia, and Rhinomusca. During periods of peak seasonal abundance, up to 3,000 Stomoxys per day were collected in an octenol-baited Vavoua trap. These high catches suggest that Vavoua traps may be of practical use for fly control in isolated settings at a relatively low cost.

The Screening Level Concentration (SLC) approach was used to derive Lowest Effect Level (LEL) and Severe Effect Level (SEL) concentrations for nine metals (As, Cr, Cu, Pb, Mo, Ni, Se, U and V) and three radionuclides (226Ra, 210Pb, and 210Po) released to the aquatic environment during the mining and milling of uranium ore. This method was chosen because it allowed for the best use of the considerable historical and current data collected for diverse purposes in the uranium mining and milling regions of Canada (20,606 data points used in the analysis). Except for Cr, all the LELs derived in this study using the weighted method and published sediment quality guidelines (SQGs) were highly reliable (> 85%) in predicting sites unimpacted by uranium mining/milling defined as sites where reductions in the abundance and species richness of benthic invertebrate communities were < 20%. The derived SEL values and corresponding published SQGs (with the exception of Ni) were not reliable predictors (< or = 60%) of severe impacts on benthic invertebrate communities when severe impacts are defined as a reduction in abundance and species richness > or = 40%. Most of the severely impacted sites had sediment contaminant concentrations well below the SEL values. It is concluded that LELs derived using the weighted method can reliably be used in ecological risk assessments as concentrations below which adverse effects on benthic invertebrate communities are not expected. In contrast, it is recommended that SELs not be used in assessments of uranium mining/milling activities as concentrations above which adverse effects are anticipated.

Here we describe field trials designed to standardize tools for the control of Glossina tachinoides, G. palpalis gambiensis and G.morsitans submorsitans in West Africa based on existing trap/target/bait technology. Blue and black biconical and monoconical traps and 1 m2 targets were made in either phthalogen blue cotton, phthalogen blue cotton/polyester or turquoise blue polyester/viscose (all with a peak reflectance between 450–480 nm) and a black polyester. Because targets were covered in adhesive film, they proved to be significantly better trapping devices than either of the two trap types for all three species (up to 14 times more for G. tachinoides, 10 times more for G. palpalis gambiensis, and 6.5 times for G. morsitans submorsitans). The relative performance of the devices in the three blue cloths tested was the same when unbaited or baited with a mixture of phenols, 1-octen-3-ol and acetone. Since insecticide-impregnated devices act via contact with flies, we enumerated which device (traps or targets) served as the best object for flies to land on by also covering the cloth parts of traps with adhesive film. Despite the fact that the biconical trap proved to be the best landing device for the three species, the difference over the target (20–30%) was not significant. This experiment also allowed an estimation of trap efficiency, i.e. the proportion of flies landing on a trap that are caught in its cage. A low overall efficiency of the biconical or monoconical traps of between 11–24% was recorded for all three species. These results show that targets can be used as practical devices for population suppression of the three species studied. Biconical traps can be used for population monitoring, but a correction factor of 5–10 fold needs to be applied to captures to compensate for the poor trapping efficiency of this device for the three species.

The population cycles of meadow voles (Microtus pennsylvanicus) were studied in southeastern Manitoba, Canada, from 1968 to 1978 on a 32—ha old field and in surrounding boreal forest. Vole density was monitored on mark—recapture live—trapping at 2— to 4—wk intervals throughout the year. This was supplemented by a 3—d spring and a 30—d summer snap—trapping survey. Multiannual and annual fluctuations in density of Microtus were independent of a diversity of patterns seen in other small mammal species. Principal components analysis of demographic statistics was used to characterize changes in seasonal reproduction, survival, and dispersal that accounted for the observed numerical fluctuations. Conditions during a catastrophic winter population decline in 1970—1971 were compared with those in 1974—1975, when numbers recovered quickly after a modest spring decline. Voles were in good condition before and during both declines, as evidenced by normal body composition indices. Large body masses, characteristic of peak populations, preceded both population declines. The main conditions associated with the 1970—1971 decline were unusual patterns in social behavior and dispersal. Changes in social behavior in the field were reflected in unprecedented numbers of multiple captures in Longworth traps before and during this decline. Field observations were supported by unusually high frequencies of amicable behavior in neutral arena bouts staged between males removed from a control population. Little dispersal was detected with conventional live—trapping during the winter period of chronic mortality in 1971. In contrast, a period of acute mortality, resulting in the near extinction of the population in March 1971, was associated with considerable dispersal. We propose two alternative hypotheses consistent with the unpredictable and episodic nature of vole population declines: (1) an immunological dysfunction exists in voles that makes them susceptible to naturally occurring microparasites or (2) opportunistic, pathogenic microparasites exploit the changes in dispersal and social contacts that occur as a normal part of the vole population cycle.

Octenol (1-octen-3-ol), acetone, 4-methylphenol, 3-n-propylphenol, and other potential attractants (human urine, stable fly faeces), as well as guiacol, creosol (potential repellents), were tested as baits for biting flies in North America using standard phthalogen blue IF3GM cotton Nzi traps, or similar commercial polyester traps. Baits were tested during the summers of 2001-04 at a residence in Canada and during January-August 2001 at a dairy in the U.S.A. Behaviour in the presence of octenol was also studied by intercepting flies approaching a trap through the use of transparent adhesive film. Analogous bait and/or trap comparisons were conducted in natural settings in June 1996 in Kenya and in September-December 1997 in Ethiopia. In Canada, catches of five of six common tabanids (Tabanus similis Macquart, Tabanus quinquevittatus Wiedemann, Hybomitra lasiophthalma [Macquart], Chrysops univittatus Macquart, Chrysops aberrans Philip) and the stable fly Stomoxys calcitrans L. were increased significantly by 1.2-2.1 times with octenol (1.5 mg/h). Catches of T. quinquevittatus and S. calcitrans were 3.5-3.6 times higher on a sticky enclosure surrounding a trap baited with octenol. No other baits or bait combinations had an effect on trap catches in North America. In Ethiopia, standard Nzi traps baited with a combination of acetone, octenol and cattle urine caught 1.8-9.9 times as many Stomoxys as similarly baited epsilon, pyramidal, NG2G, S3, biconical and canopy traps, in order of decreasing catch. When baits were compared, catches in Nzi traps of six stable fly species, including S. calcitrans, were not affected by octenol (released at approximately 1 mg/h), or cattle urine (140 mg/h), used alone or in combination with acetone (890 mg/h). Acetone alone, however, significantly increased the catches of common Stomoxys such as Stomoxys niger niger Macquart, Stomoxys taeniatus Bigot, and S. calcitrans by 2.4, 1.6 and 1.9 times, respectively. Catches of Glossina pallidipes Austen were increased significantly in traps baited with acetone, urine or octenol, or any combination, relative to those in unbaited traps (1.4-3.6x). Catches of Glossina morsitans submorsitans Newstead were increased significantly by 1.5-1.7 times, but only when baits were used individually. Unlike other studies with East African tsetse, catches of both tsetse species with the complete bait combination (acetone, urine and octenol) did not differ from those in unbaited traps. Experiments with an incomplete ring of electric nets surrounding a Nzi trap, and a new approach using a sticky enclosure made from transparent adhesive film, revealed diverse responses to artificial objects and baits among biting flies. In Kenya, daily trap efficiency estimates for traps baited with either carbon dioxide (6 L/min) or a combination of acetone, cattle urine and octenol were 21-27% for G. pallidipes, 7-36% for Glossina longipennis Corti, 27-33% for S. n. niger, and 19-33% for Stomoxys niger bilineatus Grünberg, assuming 100% electrocution efficiency. Actual trap ...

Cow urine and the two phenols responsible for the attraction of biting flies to cow urine (4-methylphenol, 3-n-propylphenol) were compared with octenol (1-octen-3-ol) as baits for Tabanidae. Relative to an unbaited Nzi trap, catches of the horseflies Hybomitra lasiophthalma (Macquart), Tabanus similis Macquart and Tabanus quinquevittatus Wiedemann (Diptera: Tabanidae) were increased by 1.5-2.6, 1.4-2.0 and 1.4-1.9 times, respectively, whenever a bait included octenol released at either 0.13 mg/h or 1.5 mg/h, regardless of the presence of phenols or urine. Catches were not affected when traps were baited with phenols alone at evaporation rates of 0.38 mg/h (4-methylphenol) and 0.022 mg/h (3-n-propylphenol). Catches of Hybomitra horseflies were increased by 1.5-1.9 times with cow urine and 2.6 times with cow urine + octenol. This bait combination could prove to be particularly useful for Hybomitra horseflies, the common tabanids of northern environments.