Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-24T07:42:24.210Z Has data issue: false hasContentIssue false

Some factors affecting substrate preferences by black-fly pupae (Diptera: Simuliidae)

Published online by Cambridge University Press:  19 September 2011

D. M. Roberts
Affiliation:
Department of Zoology, University of Jos, P.M.B. 2084, Jos, Nigeria
Get access

Abstract

A comparison was made of the relative abundance of three species of black-fly pupae colonising three natural substrates in the River Assob, in central Nigeria. Simulium hargreavesi, S. squamosum and S. vorax preferred trailing roots, whereas S. cervicomutum, S. unicomutum and S. impukane preferred dead leaves and to a lesser extent, rocks.

In order to see whether this was a preference between cylindrical and flat surfaces, polythene strips were compared with polythene strings and a smooth surface was compared with a rough one. Results are presented for the three most abundant species S. squamosum, S. hargreavesi and S. cervicomutum. All markedly avoided the rough string. S. squamosum and S. hargreavesi preferred smooth strings, whereas S. cervicomutum had no significant preference between smooth strips and strings (although slightly preferring strips). These findings are discussed in relation to natural habitats and sampling bias.

Résumé

On a fait une comparison de l'abondance relative de trois espèces des nymphes des simulies qui colonisent trois supports naturels de la rivière Assob au Nigeria central. Simulium hargreavesi, S. squamosum et S. vorax préféraient les racines traînantes pendant que S. cervicomutum, S. unicomutum et S. impukane préféraient les feuilles fanées, et un peu moins, les roches.

Pour voir si cette préférence venait des surfaces cylindriques ou plates, on comparait des bandes de polythene avec les cordes de polythene; au même temps on comparait une surface lisse avec une surface rugeuse. On présente les résultats pour les trois espèces les plus abondantes, S. squamosum, S. hargreavesi et S. cervicomutum. Tous n'ainaient pas les cordes rugeuses. S. squamosum et S. hargreavesi préferaient les cordes lisses, pendant que S. cervicomutum ainait presque également les bandes lisses et les cordes lisses; les bandes lisses etaient un petit peu plus populaires. On discute ces découvertes au rapport des habitats naturels et du biais des echantillons.

Type
Research Articles
Copyright
Copyright © ICIPE 1986

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

REFERENCES

Benfield, E. F., Hendricks, A. C. and Cairns, J. (1974) Proficiencies of two artificial substrates in collecting stream macroinvertebrates. Hydrobiologia 45, 431440.CrossRefGoogle Scholar
Carlsson, G. (1967) Environmental factors influencing black-fly populations. Bull. Wld Hlth Org. 37, 139150.Google Scholar
Chutter, F. M. (1968) On the ecology of fauna of stones in the current of a South African river supporting a very large Simulium (Diptera) population. J. appl. Ecol. 5, 531561.CrossRefGoogle Scholar
Crosskey, R. W. (1957) The Simuliidae (Diptera) of northern Nigeria. Bull. ent. Res. 48, 5974.CrossRefGoogle Scholar
Disney, R. H. L. (1972) Observations on sampling preimaginal populations of blackflies (Diptera: Simuliidae) in West Cameroon. Bull. ent. Res. 61, 485503.CrossRefGoogle Scholar
Doby, J. M., Rault, B. and Beaucournu-Saguez, F. (1967) Utilisation de rubans de plastique pour la récolte des oeufs et des stades larvaires et nymphaux de simulies (Diptères, Paranematocères) et pour l'étude biologique de ceux-ci. Annls Parasit, hum. comp. 42, 651657.CrossRefGoogle Scholar
Fredeen, F. J. H. and Spurr, D. T. (1978) Collecting semi-quantitative samples of black-fly larvae (Diptera: Simuliidae) and other aquatic insects from large rivers with the aid of artificial substrates. Quest. Ent. 14, 411431.Google Scholar
Freeman, P. and deMeillon, B. (1953) Simuliidae of the Ethiopean Region. British Museum (Natural History), London.Google Scholar
Gersabeck, E. F. and Merritt, R. W. (1979) The effect of physical factors on the colonisation and relocation behaviour of immature black flies (Diptera: Simuliidae). Environ. Ent. 8, 3439.CrossRefGoogle Scholar
Johnson, A. F. and Pengally, D. H. (1966) A cone trap for immature blackflies (Diptera: Simuliidae). Proc. ent. Soc. Ont. 96, 120.Google Scholar
Lewis, D. H. and Bennett, G. F. (1974) An artificial substrate for the quantitative comparison of the densities of larval simuliid (Diptera) populations. Can. J. Zool. 52, 773775.CrossRefGoogle Scholar
Snedecor, G. W. and Cochrane, W. G. (1967) Statistical Methods. Iowa State University Press, Iowa.Google Scholar
Tarshis, I. B. (1966) Use of fabrics in streams to collect black fly larvae. Ann. ent. Soc. Am. 61, 960961.CrossRefGoogle Scholar
Williams, T. R. and Obeng, L. (1962) A comparison of two methods of estimating changes in Simulium larval populations, with a description of a new method. Ann. trop. Med. Parasit. 56, 350361.CrossRefGoogle ScholarPubMed