Tsetse (Diptera: Glossinidae) eradication by aerial (helicopter) spraying of persistent insecticides in Nigeria

Abstract

The technique of applying persistent insecticides (largely dieldrin or endosulfan) from the air by helicopter against Glossina spp. in northern Nigeria is described. In the Guinea savanna vegetation zone, a high degree of discrimination was practised. Where the riverine species G. tachinoides Westw. and G. palpalis palpalis (R.-D.) only were present, spraying was confined to the fringing forest vegetation along drainage lines and in flood plains. Where the savanna species G. morsitans submorsitans Newst. was also present, Isoberlinia woodlands were also sprayed in swaths along the outside edges and penetrating swaths at maximum intervals of 200 m; the denser vegetation encircling the many flat-topped hills was also sprayed, as well as the main tracks and cattle routes. The more undifferentiated woodlands in the southern Guinea savanna zone were sprayed as a grid with swaths at intervals of 150 to 200 m. The degree of discrimination varied according to the fly species and density of the vegetation; usually 5 to 16% of the totally infested area was actually sprayed. So far, approximately 10 000 km 2 have been reclaimed from tsetse by this technique. The degree of reinvasion encountered per annum was approximately 25% of each project area. All reinfested areas have been successfully resprayed. Costs averaged approximately 18 Naira/ha actually sprayed or 2 Naira/ha of reclaimed area in the northern Guinea savanna zone. In the southern Guinea savanna zone, the reclaimed area averaged 3 Naira/ha. The ultra-low-volume spraying technique was introduced in 1972, and this has gradually replaced the conventional spraying technique using emulsion concentrates and booms and nozzles. The ULVA-Bals single-disc atomisers were modified and improved so that droplet sizes within a range of 70 to 200 ju,m volume median diameter can be produced as required. Many insecticide have been tested in the laboratory, preliminary tests on permethrin indicate; that it may prove to be a useful alternative to dieldrin and endosulfan.

Evolving anti-disease strategies from biochemical pathogenesis of african trypanosomiasis

“…In this context, anti-disease strategies against African trypanosomiasis, in the broadest sense, may include: a) prevention of infection by breaking trypanosome transmission through avoiding contact with vectors by using odour-baited traps and screens to remove vectors from the vicinity of the host, 75 deploying synthetic or natural animal-derived vector repellents on the host 76,77 and/or elimination of vectors in the environment by aerial insecticide sprays [78][79][80][81] and integrated vector control using sterile insect technique; 82,83 97 considered, in a review, that anti-disease strategies could be targeted at treatments which did not eliminate the trypanosomes, but prevented the invasion of the brain by maintenance of blood brain barrier, neutralized the toxic products of trypanosomes, modulated the immune processes towards regulation of inflammation, reduction of effect of tumour necrosis factor, amplification of TGF-beta 1 and prevention of apoptosis of lymphocytes. Therefore, the anti-disease strategies propose to promote disease tolerance which is an ability of the host to limit the health consequences of the infective pathogen in spite of burden of infection.…”

Salivary Gland Hypertrophy Viruses: A Novel Group of Insect Pathogenic Viruses

“…Environmentally acceptable tsetse control tactics include stationary bait techniques (29), the live bait technique (10), the sequential aerosol technique (45), and the sterile insect technique (SIT) (66,70,87). Applying the control effort on an area-wide (AW) basis, i.e., against an entire tsetse population within a circumscribed area (46,48,85), has resulted in more sustainable control (17,45,80,87) compared with localized IPM where the control effort was directed against only parts of the tsetse population (9).…”

A dynamic population model for tsetse (Diptera: Glossinidae) area‐wide integrated pest management

“…Cheap, persistent organochlorine insecticides such as DDT became widely available after World War II and formed the basis for successful large-scale tsetse eradication campaigns, e.g., in South Africa (Du Toit 1954), Nigeria (Spielberger et al 1977), and Zimbabwe (Shereni 1990). In the 1980s-1990s, environmental concerns and the removal of some very effective chemicals from the control arsenal have driven a shift from centrally organized control campaigns that relied mostly on the use of insecticides to smaller, localized control efforts under the management of the local farmer (Vreysen 2006).…”