Skip to main content
    • Aa
    • Aa

Seasonal and diurnal variations in physiological age and trypanosome infection rate of females of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst

  • J. M. B. Harley (a1)

A series of 24-hr. catches of Glossina from bait-oxen was carried out during 16 months in 1962–63 at Lugala, Uganda, where G. pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. occur. Female flies were dissected to determine their physiological age and the presence or absence of trypanosomes. Five age-categories were distinguished, depending on whether a fly had ovulated 0, 1, 2, 3 or more (4 + ) times. Flies remained in each of the first four categories for about 11 days and the fifth therefore comprised those over 40–50 days old. Trypanosome infections were classified as brucei-type, vivax-iype or congolense-type (i.e., attributable to trypanosomes of the groups of Trypanosoma brucei, T. vivax and T. congolense) according to the sites in which they were found.

In all three species of Glossina, vivax-tjpe infections were commonest and alone showed seasonal fluctuations in incidence. Infections of the brucei-type were rare. The total infection rate (all types) in G. pallidipes and G. palpalis fuscipes was highest in or immediately after months of greatest rainfall and relatively lower in dry months; the highest infection rates in G. brevipalpis occurred a month later than those of the other two species. Over 80 per cent, of infections in all three were found in category 4+ flies, the percentage of which in the catches varied in much the same way as the total infection rate, suggesting not only that the flies live longest during wet periods but also that fluctuations of infection rate are largely due to changes in mean age. The regression of total infection rate on percentage of category 4 + flies was significant for G. palpalis fuscipes over 14 months, and for G. pallidipes over 12 months, but insignificant for G. brevipalpis.

The age-composition of catches of G. pallidipes and G. brevipalpis but not G. palpalis fuscipes varied during the day. In G. pallidipes, the percentage of older flies was higher in the middle of the day than in the early morning and late evening, and these contrasts were reflected in the infection rate, which was highest in samples taken in the middle of the day. In G. brevipalpis, the percentage of oldier flies and also the infection rate were lower during the night than during the day.

Estimates were made of the mean number of bites by infected females that would be received by one ox in one day. The number varied from month to month, with peaks shortly after periods of high rainfall, mainly as a result of changes in fly density and relatively little as a result of changes in infection rate. G. pallidipes, the most numerous species, was responsible for most of the potentially infective bites.

Hide All
Van Den Berghe L., Chardome M. & Peel E. (1958). Les trypanosomes transmis par Glossina morsitans au Mutara (Ruanda).—Annls Soc, beige Méd. trop. 38 pp. 965970.
Burtt E. (1946). Incubation of tsetse pupae; increased transmission-rate of Trypanosoma rhodesiense in Glossina morsitansAnn. trop. Med. Parasit. 40 pp. 1828.
Buxton P. A. (1955). The natural history of tsetse flies.—Mem. Lond. Sch. Hyg. trop. Med. no. 10, 816 pp.
Chorley J. K. (1929). Experiments in grass fires against Glossina morsitans in Southern Rhodesia.—Bull. ent. Res. 20 pp. 377390.
Davies L. (1955). Behaviour of young and old females of the black-fly, Simulium ornatum Mg.—Nature, Lond. 176 no. 4490 pp. 979980.
Desowitz R. S. & Fairbairn H. (1955). The influence of temperature on the length of the development cycle of Trypanosoma vivax in Glossina palpalis.—Ann. trop. Med. Parasit. 49 pp. 161163.
Downes J. A. (1950). Habits and life-cycle of Culicoides nubeculosus Mg.— Nature, Lond. 166 pp. 510511.
Duke B. O. L. (1960). Studies on the biting habits of Chrysops VII.—The biting-cycles of nulliparous and parous C. silacea and C. dimidiata (Bombe form).—Ann. trop. Med. Parasit. 54 pp. 147155.
Fairbairn H. & Culwick A. T. (1950). The transmission of the polymorphic trypanosomes.—Acta trop. 7 pp. 1947.
Fairbairn H. & Watson H. J. C. (1955). The transmission of Trypanosoma vivax by Glossina palpalis.—Ann. trop. Med. Parasit. 49 pp. 250259.
Ford J. & Leggate B. M. (1961). The geographical and climatic distribution of trypanosome infection rates in G. morsitans group of tsetse flies (Glossina Wied., Diptera).—Trans. R. Soc. trop. Med. Hyg. 55 pp. 383397.
Glasgow J. P. & Duffy B. J. (1961). Traps in field studies of Glossina pallidipes Austen.—Bull. ent. Res. 52 pp. 795814.
Harley J. M. B. (1965a). Activity cycles of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst.—Bull. ent. Res. 56 pp. 141160.
Harley J. M. B. (1965b). Seasonal abundance and diurnal variations in biting activity of some Stomoxys and Tabanidae in Uganda.—Bull. ent. Res. 56 pp. 319322.
Jackson C. H. N. (1941). The economy of a tsetse population.—Bull. ent. Res. 32 pp. 5355.
Jackson C. H. N. (1948). The analysis of a tsetse population. III.—Ann. Eugen. 14 pp. 91108.
Leggate B. M. (1963). Trypanosome infections in Glossina morsitans West, and G. pallidipes Aust. under natural conditions.—Ninth Meet. int. scient. Commn Tryp. Res., 1968 pp. 213227.
Lloyd Ll., Johnson W. B., Young W. A. & Morrison H. (1924). Second report of the tsetse-fly investigation in the Northern Provinces of Nigeria. —Bull. ent. Res. 15 pp. 127.
Lumsden W. H. R. (1952). The crepuscular biting activity of insects in the forest canopy in Bwamba, Uganda. A study in relation to the sylvan epidemiology of yellow fever.—Bull. ent. Res. 42 pp. 721760.
Nash T. A. M. (1936). The relationship between the maximum temperature and the seasonal longevity of Glossina submorsitans Newst., and G. tachinoides Westw., in Northern Nigeria.—Bull. ent. Res. 27 pp. 273279.
Nash T. A. M. (1939). The ecology of the puparium of Glossina in Northern Nigeria.—Bull. ent. Res. 30 pp. 259284.
Nash T. A. M. & Page W. A. (1953). The ecology of Glossina palpalis in Northern Nigeria.—Trans. R. ent. Soc. Lond. 104 pp. 71169.
Saunders D. S. (1962). Age determination for female tsetse flies and the age composition of samples of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst.—Bull. ent. Res. 53 pp. 579595.
Squire F. A. (1951). Seasonal variation in the incidence of Trypanosoma vivax in Glossina palpalis (R.-D.).—Bull. ent. Res. 42 pp. 371374.
Squire F. A. (1954). Observations on the incidence of trypanosomes in Glossina palpalis (R.-D.) in Sierra Leone.—Bull. ent. Res. 45 pp. 797801.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Bulletin of Entomological Research
  • ISSN: 0007-4853
  • EISSN: 1475-2670
  • URL: /core/journals/bulletin-of-entomological-research
Please enter your name
Please enter a valid email address
Who would you like to send this to? *


Full text views

Total number of HTML views: 0
Total number of PDF views: 2 *
Loading metrics...

Abstract views

Total abstract views: 34 *
Loading metrics...

* Views captured on Cambridge Core between September 2016 - 22nd October 2017. This data will be updated every 24 hours.