Strategies to combat the desert locust

Symmons, P. M.

doi:10.1016/0261-2194(92)90038-7

Cited by 57 publications

(25 citation statements)

References 5 publications

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“…Their presence has varied from four out of every five years between 1860 and 1963 to one year in six subsequently (Waloff 1976, Symmons 1992. Between 1973 and 1994, there have been a further six periods of notable gregarisation.…”

Section: Desert Locust Distribution and Biologymentioning

confidence: 96%

A GIS for desert locust forecasting and monitoring

Healey

Robertson

Magor

et al. 1996

International Journal of Geographical Information Systems

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Desert locust plagues can affect up to 20 per cent of the surface of the Earth. Data on locust breeding, environmental conditions and swarm movements in affected countries, are collected at the headquarters of the U.N. Food and Agriculture Organization in Rome. GIs technology coupled with remote sensing inputs allows these data to be utilised for monitoring and forecasting purposes much more effectively than heretofore. Design requirements and the implementation strategy for such a GIS are examined, emphasizing the role of global digital map datasets such as the Digital Chart of the World, the importance of effective data integration and the need for an ergonomic user interface that facilitates both data capture and analysis.

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Section: Desert Locust Distribution and Biologymentioning

confidence: 96%

A GIS for desert locust forecasting and monitoring

Healey

Robertson

Magor

et al. 1996

International Journal of Geographical Information Systems

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“…), has been an important agricultural pest since biblical times. It was estimated that during a 1986-89 plague which affected all the Sahelian countries in north Africa and some parts of southwest Asia, 17 million ha of ecologically fragile locust-infested area was treated with about 12 million litres of liquid pesticides and 27 000 tonnes of dusts and baits, costing about US$200 million (Symmons, 1992;G. B. Popov, personal communication).…”

Section: Introductionmentioning

confidence: 98%

Models for estimation of population density of late instar nymphs and fledglings of the desert locust,Schistocerca gregaria(Forsk.)

Bashir

Inayatullah

Ahmed

et al. 1993

International Journal of Pest Management

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Precise estimation of numbers of gregariously behaving desert locust, Schistocerca gregaria (Forsk.), populations is essential for the development of an economical control strategy. Such an estimate should facilitate proper deployment of scarce available resources frequently needed at widely scattered sites in infested areas. A simple, less time-consuming, yet precise and cost-saving technique for estimating absolute numbers of locusts based on plant counts has been developed. It was observed that on the Red Sea Coast of Sudan, which is a major locust breeding and recession area, locusts take shelter in different bushy plants including Panicum turgidum and Salsola forskalii. The numbers of locusts present in each plant were found to be highly correlated with its size. Simple linear regression models accounted for about 70% variability, when plant perimeter was used as a predictor variable. These models can be used to estimate locust numbers on a plant of a given size. Thus the number of infested plants in a sample area can be counted, and the locust density calculated mathematically. It was observed that in the study area P. turgidum and S. forskalii covered about 3.18% and 4.05% of the ground surface, respectively. The estimated density of locusts was 15.7 × 10 6 individuals per km 2 in a total infested area of 4 km 2 . Hence the swarm which was expected to fly out of that area would contain approximately 62.8 x 10 6 locusts.

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“…Cauquil and Vaissayre (1995) have reported on the extensive use of these sprayers to treat nearly 2 million hectares of cotton in West Africa. ULV spraying is often the only viable option for control of migrant pests such as locusts (Symmons, 1992) and in forestry, where very large areas of land must be treated quickly. This high work rate has also helped to promote the use of CDA by local authorities for herbicide application in amenity areas.…”

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confidence: 99%

Controlled droplet application

Bateman¹

2014

Pesticide Application Methods

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In contrast to the relatively wide range of droplet sizes produced by hydraulic nozzles, controlled droplet application (CDA) involves atomisation where an appropriate droplet size is selected to optimise deposition on the intended spray target (Bals, 1975b;Matthews, 1977). Fraser (1958), Himel (1974 and others had previously stressed the need for a nozzle that produces a narrow spectrum of droplet sizes to avoid losses caused by off-target spray drift or run-off or both (i.e. minimising 'exo-drift and endo-drift'). Bals (1969) pioneered the development of rotary nozzles for agricultural use, which achieved relatively narrow droplet spectra and later the term CDA was coined (probably by John Fryer, previously of the UK Weed Research Organisation) to differentiate the question of droplet size from the use of formulations sprayed at ultra low-volume rates. Minimising spray drift is a crucial issue in pesticide application and Gilbert and Bell (1988) demonstrated that rotary atomisers could substantially reduce the potential for exposure to fine droplets in comparison with conventional hydraulic nozzles, 50 m downwind of the spray line.Controlled droplet application as a concept developed from an obvious need for greater efficiency when applying sprays at ultra low-volume (ULV) rates of application. It should be emphasised that the two terms are not necessarily synonymous, but are frequently interchanged since the homogeneity of droplet size (CDA) enables effective ULV spraying; with volume application rates of only 0.5-3 litres of spray per hectare, it is essential to avoid large droplets that waste a high proportion of the pesticide (see Chapter 4).Several laboratory and glasshouse studies subsequently demonstrated that smaller droplets are also more efficacious for arthropod pest control than larger ones (e.g. Adams et al., 1990). 30-60 μm droplets were usually optimal with oil-based spray deposits, but 60-120 μm was most efficient with aqueous droplets, so formulation is also a key factor (see p. 257). A review of droplet size and carrier volume suitable for foliage-applied herbicides is given by Knoche (1994).Controlled droplet application at ULV rates has been widely adopted in semi-arid areas where water supplies are poor and prevent widespread adoption of higher volume spraying techniques. In particular, large areas of cotton in both central-southern and West Africa have been treated with spinning

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Strategies to combat the desert locust

Cited by 57 publications

References 5 publications

A GIS for desert locust forecasting and monitoring

A GIS for desert locust forecasting and monitoring

Models for estimation of population density of late instar nymphs and fledglings of the desert locust,Schistocerca gregaria(Forsk.)

Controlled droplet application

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