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Biomedical subjects

C S Lofgren

Publications and source records attributed to C S Lofgren.

At least 37 records · Page 2Linked to original sources
PubMed1974

Recent developments in methods of mosquito control.

Since residual insecticide spraying in domiciles does not sufficiently control some species of anophelines to halt malaria transmission, alternate methods of control have been investigated. These include ultra-low-volume (ULV) sprays or aerosols, the release of sterile males to suppress or eradicate populations, and the use of diseases or parasites to interfere with transmission or to reduce populations of mosquitos. The ULV aerial sprays gave practical control of Anopheles albimanus in Haiti and interrupted malaria transmission. The release of sterile males almost eliminated an isolated population of A. albimanus in a small valley in El Salvador. Studies are in progress to evaluate the effect on field populations of anophelines of a protozoan disease and two nematode parasites.

Animals↗
PubMed1973

Aerial applications of ultra-low-volume insecticides to control the vector of Japanese encephalitis in Korea.

As a suitable emergency measure to arrest epidemics of Japanese encephalitis in Korea, the ultra-low-volume method of spraying insecticide to control the mosquito vector Culex tritaeniorhynchus has been tested in 2 successive years over a 16-km (2) area, utilizing a large fixed-wing aircraft. Malathion concentrate applied at 0.36 litres/ha gave insufficient control of the parous (infective) females, and no reduction in total numbers of this species. Fenitrothion concentrate applied at 0.45 litres/ha resulted in a 77-87% reduction in total numbers and an 87-98% reduction in parous females over a 4-day period.

Aircraft↗
PubMed1972

Insect sterility in population dynamics research.

This paper reviews and discusses a technique that can be used to study the dynamics of populations under the influence of favourable or unfavourable environmental factors or the stress of population control. It is encouraging for those interested in the sterility approach to pest control that the reproductive success of insects with a reputedly high biotic potential is limited to relatively low rates under field conditions. Further studies are needed under other conditions, in other areas, and with other species.

Animals↗
PubMed1970

The effectiveness of ultra-low-volume applications of malathion at a rate of 6 US fluid ounces per acre in controlling Aedes aegypti in a large-scale test at Nakhon Sawan, Thailand.

The effectiveness of ultra-low-volume (ULV) applications of technical malathion to control Aedes aegypti was studied in Nakhon Sawan, Thailand, in November 1968. Two treatments of 6 US fl oz/acre (438 ml/ha) were applied 4 days apart by a C-47 aircraft equipped with a fuselage-mounted spraying boom. An area of 7 square miles (18 km(2)), which included the entire city area, was treated.The landing rate of adult A. aegypti adults was reduced significantly following each malathion application (95% and 99%, respectively), the reduction ranging from 88% to 99% during the 10-day post-treatment observation period. No eggs were deposited in ovitraps 4 days after the first application. Dissections of female mosquitos collected during the post-treatment period showed that only 8% of the females were parous compared with 30% before treatment and 40% in the check area. Night landing rates of other mosquitos were reduced by 82%-97%; housefly populations also decreased markedly. The test results indicate that UVL treatments with malathion applied by aircraft can be used to control A. aegypti during outbreaks of dengue haemorrhagic fever. The fuselage-mounted spraying system used in the tests performed very well. The equipment can be mounted on, and removed from, a C-47 aircraft very quickly, thus making it possible to convert such aircraft used for other purposes into spraying planes at quite short notice.

Aedes↗
PubMed1970

The effectiveness of ultra-low-volume applications of malathion at a rate of 3 US fluid ounces per acre in controlling Aedes aegypti in Thailand.

Ultra-low-volume (ULV) aerial applications of malathion at a rate of 3 US fl oz per acre (219 ml/ha) for the control of Aedes aegypti and Culex pipiens fatigans were evaluated in 2 areas near Bangkok, Thailand. A housing project of the Royal Thai Air Force received 2 applications a week apart while the village of Bang Khen received 1 application. Bioassays, oil-sensitive red dye cards, landing-rate counts, ovitraps, and light-traps were used to evaluate the effects of the treatment. A comparison of pre- and post-treatment indices indicated good control of A. aegypti following all treatments. The results of these tests when compared with those of an earlier study using 6 US fl oz/acre (438 ml/ha) showed that the higher rate of application rate was more effective. Only fair control of C. p. fatigans was obtained. A comparison of light-trap collections before and after treatment demonstrated fairly good over-all control of other species of mosquitos for 3-4 days following each of the 2 treatments on the Air Force housing area.

Aedes↗