Field trials of baits to control populations of <i>Glossina morsitans morsitans</i> Westwood and G. pallidipes Austen (Diptera: Glossinidae)

Vale, G. A.; Hargrove, John W.; Cockbill, G. F.; Phelps, R. J.

doi:10.1017/s000748530001467x

Cited by 106 publications

(87 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For savannah (morsitans) flies present in the study area (i.e. Glossina pallidipes, G. morsitans, G. swinnertoni, and G. austeni) 4 traps or targets per km 2 , baited with attractants, are considered sufficient to reduce tsetse populations by ≈ 95% in non-isolated populations or to eliminate an isolated population as demonstrated by field trials (Vale et al, 1986;Vale et al, 1988;Dransfield et al, 1990). Riverine (palpalis) flies (G. fuscipes and G. tachinoides in the study region) are relatively unresponsive to odours and higher densities of baits are therefore required (Green, 1994.…”

Section: Stationary Baits -Targets and Trapsmentioning

confidence: 99%

Mapping the benefit-cost ratios of interventions against bovine trypanosomosis in Eastern Africa

Shaw

Wint

Cecchi³

et al. 2015

Preventive Veterinary Medicine

View full text Add to dashboard Cite

This study builds upon earlier work mapping the potential benefits from bovine trypanosomosis control and analysing the costs of different approaches. Updated costs were derived for five intervention techniques: trypanocides, targets, insecticide-treated cattle, aerial spraying and the release of sterile males. Two strategies were considered: continuous control and elimination. For mapping the costs, cattle densities, environmental constraints, and the presence of savannah or riverine tsetse species were taken into account. These were combined with maps of potential benefits to produce maps of benefit-cost ratios. The results illustrate a diverse picture, and they clearly indicate that no single technique or strategy is universally profitable. For control using trypanocide prophylaxis, returns are modest, even without accounting for the risk of drug resistance but, in areas of low cattle densities, this is the only approach that yields a positive return. Where cattle densities are sufficient to support it, the use of insecticidetreated cattle stands out as the most consistently profitable technique, widely achieving benefit-cost ratios above 5. In parts of the high-potential areas such as the mixed farming, high-oxen-use zones of western Ethiopia, the fertile crescent north of Lake Victoria and the dairy production areas in western and central Kenya, all tsetse control strategies achieve benefit-cost ratios from 2 to over 15, and for elimination strategies, ratios from 5 to over 20. By contrast, in some areas, notably where cattle densities are below 20 per km 2 , the costs of interventions against tsetse match or even outweigh the benefits, especially for control scenarios using aerial spraying or the deployment of targets where both savannah and riverine flies are present. If the burden of human African trypanosomosis were factored in, the benefit-cost ratios of some of the low-return areas would be considerably increased. Comparatively, elimination strategies give rise to higher benefit-cost ratios than do those for continuous control. However, the costs calculated for elimination assume problem-free, large scale operations, and they rest on the outputs of entomological models that are difficult to validate in the field. Experience indicates that the conditions underlying successful and sustained elimination campaigns are seldom met. By choosing the most appropriate thresholds for benefit-cost ratios, decision-makers and planners can use the maps to define strategies, assist in prioritising areas for intervention, and help choose among intervention techniques and approaches. The methodology would have wider applicability in analysing other disease constraints with a strong spatial component.

show abstract

Section: Stationary Baits -Targets and Trapsmentioning

confidence: 99%

Mapping the benefit-cost ratios of interventions against bovine trypanosomosis in Eastern Africa

Shaw

Wint

Cecchi³

et al. 2015

Preventive Veterinary Medicine

View full text Add to dashboard Cite

show abstract

“…The first successful application of odour-baited traps and targets to control tsetse was undertaken in Zimbabwe where traps and insecticide-treated targets baited with synthetic host odours were used to eliminate G. m. morsitans and G. pallidipes from an island (5 km 2 ) in Lake Kariba (Vale et al 1986b). Following on from this success, large-scale use of the technology began in 1984, with the deployment of insecticide-treated targets over an area of ~1000 km 2 in the Zambezi valley of Zimbabwe.…”

Section: Use Of Odour Baits To Control Morsitans Group Speciesmentioning

confidence: 99%

Olfaction in vector-host interactions

Takken¹,

Knols²

2010

View full text Add to dashboard Cite

“…(Note: E(d) = V6iA:t/ 2); Hargrove & Lange (1989)). Also, while it was assumed that q = 0.98 (the value estimated for G. pallidipes by Vale et al, 1986) the results for higher or lower values of q can be read off from the graph by adjusting the scale for target densities -as long as the changes in q are small. For example if q = 0.99 (i.e.…”

Section: T (1)mentioning

confidence: 99%

“…For G. pallidipes females with d 1 km under some circumstances (Vale et al, 1984) and q 0.98 (Vale et al, 1986) the results in figure 2A can be read off directly with the units taken as km. For G. m. morsitans the daily step length may approach 500 m and q 0.99 (Vale et al, 1984(Vale et al, ,1986) so that figure 2A should be read as if the abscissa is marked with target densities 8, 16, ... 128 and the barrier widths marked 0.5,1, 2, 4 km.…”

Section: T (1)mentioning

confidence: 99%

“…(Vale et al, 1986(Vale et al, , 1988Willemse, 1991). For the savannah species G. m. morsitans Westwood, G. m. centralis Machado and G. pallidipes Austen it appears that, with the attractive synthetic odours presently available, a density of about four targets/km 2 is necessary and sufficient to eradicate a tsetse population in nine months to a year -if the targets are in good working order for the whole of this period.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Target barriers for tsetse flies (Glossina spp.) (Diptera: Glossinidae): quick estimates of optimal target densities and barrier widths

Hargrove

1993

Bull. Entomol. Res.

View full text Add to dashboard Cite

The probability that tsetse flies (Glossina spp.) cross a barrier of odourbaited targets is calculated for barriers of different widths and target density, and for tsetse flies with varying natural rates of survival, daily step lengths (d) and probabilities of being killed by an odour-baited target. If the barrier is only as wide as d, and for a species which has a 2% natural daily mortality and a further 2% mortality due to each target per unit area, tsetse flies have probability (P) of ca. 0.1 of penetrating the barrier even if the target density is 64 per unit area. To ensure that P < 0.001 the barrier must be about 4rf wide for target densities 32 per unit area; doubling the width to 8d means that target densities could be cut by about 75%, and total numbers of targets in the barrier by 50%. These biological considerations and the economic costs of different target barriers suggest that, for all tsetse fly species, a safe and relatively inexpensive barrier is achieved with barrier width 8d when the optimum target density is roughly the same as for normal operational areas. This has the important practical consequence that there is no need to treat barriers as a special case. Practical results from research and control operations in Zimbabwe are in accord with the theoretical findings, but further work is required to ascertain whether the safety margin, and hence costs, can be reduced.

show abstract

Field trials of baits to control populations of Glossina morsitans morsitans Westwood and G. pallidipes Austen (Diptera: Glossinidae)

Cited by 106 publications

References 21 publications

Mapping the benefit-cost ratios of interventions against bovine trypanosomosis in Eastern Africa

Mapping the benefit-cost ratios of interventions against bovine trypanosomosis in Eastern Africa

Olfaction in vector-host interactions

Target barriers for tsetse flies (Glossina spp.) (Diptera: Glossinidae): quick estimates of optimal target densities and barrier widths

Contact Info

Product

Resources

About