Studies on the Efficiency of Collecting and Counting Anopheles Gambiae in Verandah-Trap Huts

Smith, A.; Esozed, S.

doi:10.1080/04345546709415447

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The numbers of mosquitoes indoors are determined by the numbers of dead indoors plus a daytime count of numbers resting indoors. The latter is only 60% efficient (Smith & Esozed, 1966), but the undercount leads to less than a 10% error in the calculation of egress of A. gambiae from an untreated hut, as in the example given in Table XIV, and a 2-3 % error in the calculation of egress of A. gambiae from a DDT-treated hut. The small error in the treated hut is because a smaller proportion of the total mosquitoes rest indoors in the treated than in the untreated hut.…”

Section: Deterrent Effect Of Ddtmentioning

confidence: 98%

A veranda-trap hut for studying the house-frequenting habits of mosquitoes and for assessing insecticides. III. The effect of DDT on behaviour and mortality

Smith

Webley

1969

Bull. Entomol. Res.

Self Cite

View full text Add to dashboard Cite

The effects of DDT on the behaviour and mortality of Anopheles gambiae Giles, A. funestus Giles, Mansonia uniformis (Theo.) and Culex pipiens fatigans Wied., entering experimental huts, have been studied with the assistance of gas-chromatographic techniques.Sixty to 70% of A. gambiae and 70–80% of M. uniformis were deterred from entering verandah-trap huts treated indoors with a nominal dosage of 200 μg/cm2 of DDT active ingredient. Gas chromatographic techniques indicate that the chemical basis of the deterrency was a steadily diminishing outflow of DDT from the hut, either as a dust or vapour, and the build-up of deposit on the untreated overhanging eaves to 0·02 to 0·27 μg/cm2 seven months after treatment. A. funestus was less deterred than A. gambiae and M. uniformis, but the behaviour of C. p. fatigans was almost unaffected by the DDT deposit.Overall mortalities were highest in A. funestus and M. uniformis, lower in A. gambiae and extremely low in C. p. fatigans.There was a marked irritant effect of the DDT deposit on recently blood-fed A. gambiae, some 50–70% being driven out of the treated huts. This behaviour occurred to a lesser degree in A. funestus but was absent in M. uniformis and C. p. fatigans. The chemical basis of the irritant effect was indicated to the extent that surviving mosquitoes, that left the treated hut, showed 1·5 ng/insect of DDT. Mosquitoes that died, whether indoors or after leaving the hut, picked up amounts ranging from 7 to 20 ng/insect.

show abstract

Section: Deterrent Effect Of Ddtmentioning

confidence: 98%