Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-22T18:55:32.306Z Has data issue: false hasContentIssue false

Field Tests with Larvicides against Culicoides impunctatus Goetgh. in Scotland

Published online by Cambridge University Press:  10 July 2009

D. S. Kettle
Affiliation:
Midge Control Unit, Dept. of Zoology, Edinburgh University.
Ruth H. Nash
Affiliation:
Midge Control Unit, Dept. of Zoology, Edinburgh University.
Barbara A. Hopkins
Affiliation:
Midge Control Unit, Dept. of Zoology, Edinburgh University.

Extract

Field tests were conducted on Soutra Hill (1,100 ft. above M.S.L.) in the winters of 1953–4 and 1954–5 to find a suitable larvicide for controlling Culicoides impunctatus Goetgh. In one trial, four formulations (wettable powder, water-miscible concentrate, oil solution and dust) of DDT and γ BHC were applied to plots (10 × 10 yd.) at dosages of 3, 12, 50 and 200 mg. p.p′DDT or γ BHC/sq. ft., except for the γ BHC dust which was applied at 3, 6, 12 and 25 mg. γ BHC/sq. ft. In a second trial, the larvicidal properties of aldrin, dieldrin and malathion wettable powders, chlordane water-miscible concentrate and malathion emulsi-fiable liquid were investigated at three or four of the following dosages —3, 6, 12. 25 and 50 mg./sq. ft. The conclusions to be drawn from these trials were:—

1. DDT was superior to γ BHC at all dosages and in all formulations both in immediate and residual effects.

2. For immediate larval control, DDT and γ BHC wettable powders and DDT water-miscible concentrate were effective but γ BHC water-miscible concentrate was relatively ineffective.

3. Although all the DDT preparations were effective as residual larvicides, the wettable powder was the most successful.

4. For immediate larval control a dosage of 200 mg. p, p′DDT or γ BHC is required. The effect produced by 50 mg./sq. ft. is variable.

5. For residual larvicidal action a dosage of 50 mg./sq. ft. is required although 12 mg./sq. ft. may sometimes be effective.

6. Both preparations of malathion reduced the initial larval density by just over half but they had no residual effect.

7. Chlordane and aldrin achieved an immediate larval reduction of one third but whereas chlordane had a greater residual effect, aldrin was ineffective.

8. Dieldrin had very little immediate (20 per cent. control) but considerable residual effect (72 per cent. control).

9. Wettable powders are the most successful larvicidal preparations.

10. DDT and γ BHC wettable powders at 50 mg. p, p′DDT or γ BHC/sq. ft. are superior to chlordane at the same dosage and slightly better than dieldrin at 25 mg./sq. ft.

Type
Research Paper
Copyright
Copyright © Cambridge University Press 1956

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Cameron, A. E. (1948). Scottish blood-sucking midges. —Trans. Highl. Agric. Soc. Scot., 60, pp. 6879.Google Scholar
Cameron, A. E., Downes, J. A., Morison, G. D. &Pracock, A. D. (1946). A survey of Scottish midges. —In Crew, F. A. E. & others, Control of midges, pp. 911. Edinburgh, Dep. Hlth. Scot.Google Scholar
Dorsey, C. K. (1947). Population and control studies of Palau Gnat on Peleliu, Western Caroline Islands. —J. econ. Ent., 40, pp. 805814.CrossRefGoogle ScholarPubMed
Dove, W. E., Hall, D. G. & Hull, J. B. (1932). The salt marsh sand fly problem (Culicoides). —Ann. ent. Soc. Amer., 25, pp. 505528.CrossRefGoogle Scholar
Golz, H. H. (1952). Malathion—summary of pharmacology and toxicology. — Med. Dep., Amer. Cyanamid Co.Google Scholar
Goulding, R. L., Curran, R. F. & Labrecque, G. C. (1953). Insecticides for control of salt-marsh sand flies in Florida. —J. econ. Ent., 46, pp. 3743.CrossRefGoogle Scholar
Hill, M. A. &Roberts, E. W. (1947). An investigation into the effects of ‘ gammexane ’ on the larvae, pupae and adults of Culicoides impunctatus Goetghebuer and on the adults of Culicoides obsoletus Meigen. —Ann. trop. Med. Parasit., 41, pp. 143163.Google Scholar
Kettle, D. S. (1949). An attempt to control Culicoides impunctatus Goetghebuer in Scotland by barrier-spraying. —Ann. trop. Med. Parasit., 43, pp. 284296.CrossRefGoogle Scholar
Kettle, D. S. (1951). The spatial distribution of Culicoides impunctatus Goet. under woodland and moorland conditions and its flight range through woodland. —Bull. ent. Res., 42, pp. 239291.CrossRefGoogle Scholar
Kettle, D. S. &Lawson, J. W. H. (1952). The early stages of British biting midges Culicoides Latreille (Diptera, Ceratopogonidae) and allied genera. —Bull. ent. Res., 43, pp. 421467.CrossRefGoogle Scholar
Labrecque, G. C. & Goulding, R. L. (1954). Tests with granulated BHC and dieldrin for controlling sand fly larvae. —Mosq. News, 14, pp. 2022.Google Scholar