Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-10T12:37:52.443Z Has data issue: false hasContentIssue false
  • English
  • Français

The biology and control of termites damaging field crops in Tanganyika

Published online by Cambridge University Press:  10 July 2009

M. Bigger
M. Bigger
Affiliation:
Ministry of Agriculture, Tanzania
Get access Rights & Permissions [Opens in a new window]

Extract

Many crops in southern Tanganyika are attacked by termites, especially those grown in the miombo woodland (Brachystegia-Pseudoberlinia), which covers much of the southern and western parts of the country. The termites chiefly concerned are Microtermes albopartitus (Sjöst.), M. redenianus (Sjöst.), Ancistrotermes latinotus (Hlmgr.) and Allodontermes tenax (Silv.). A pit dug to investigate their nest systems showed that M. albopartitus was the most numerous, 425 occupied cells being recovered from an area 50 × 24 ft. excavated to a depth of 6 ft. Cells of the other species included 166 of M. redenianus, 54 of Ancistrotermes latinotus and 49 of Allodontermes tenax. The cells of Ancistrotermes latinotus were aggregated into small clusters connected by long runways; those of the other species were more or less randomly scattered. The greatest concentration of cells of all species was within the top 2 ft. of the soil, but a number of cells were found at greater depths and it is certain that 6 ft. is not the maximum nesting depth. Descriptions of the nest systems and fungus combs are given.

Observations at Nachingwea in 1959–63 showed that loss of maize stands from termite attack averaged 27 per cent, over the five years, and that of soya 33 per cent. The damage was often great on individual plots, as much as 90 per cent, being recorded from one plot of maize. Plant-population counts over three growing seasons showed that maize is lost mainly towards the end of the season, whereas soya may be attacked any time after planting, increased losses occurring during dry spells and at the end of the season.

Control was achieved by the use of aldrin or dieldrin applied as dusts to the soil before planting or used in seed dressings. It was found in a series of field trials that good control of termites was afforded by aldrin worked into the soil along the planting ridges at a rate of 1 lb. active ingredient per acre, but that in practice ½ lb. per acre gave nearly as good results when measured by yields. In spite of the considerable losses, it was considered uneconomic to use aldrin to protect soya from termite attack, but the increased yields of 200–400 lb. maize per acre justified the expenditure on insecticide. The aldrin dust protected both crops for at least one further year after application, the effects on yield being of the same order as before.

A seed dressing of 75 per cent, dieldrin gave excellent control and was considerably cheaper than soil application of aldrin. The cost was only a few shillings an acre when the dressing was used at the rate of 0·1 oz. per 1 lb. seed, and the effect was to raise yields of maize by 330–500 lb. and of soya by 110–180 lb. per acre.

Trenches were dug to investigate the effects of soil treatment with aldrin on the nest systems of the termites. There was little effect on cell density eight months after application, but after 20 months there were signs of a reduction, especially in the top 9 in. of the soil.

Type
Research Paper
Information
Bulletin of Entomological Research , Volume 56 , Issue 3 , June 1966 , pp. 417 - 444
Copyright
Copyright © Cambridge University Press 1966

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

Adamson, A. M. (1943). Termites and the fertility of soils.—Trop. Agriculture (Trin.) 20 pp. 107–112.Google Scholar
Anderson, B. (1963). Soils of Tanganyika.—Bull. Tanganyika Dep. Agric. no. 16, 36 pp.Google Scholar
Bollen, W. B., Roberts, J. E. & Morrison, H. E. (1958). Soil properties and factors influencing aldrin-dieldrin recovery and transformation.—J. econ. Ent. 51 pp. 214–219.CrossRefGoogle Scholar
Grassé, P. P. (1950). Termites et sols tropicaux.—Rev. int. Bot. appl. 30 pp. 549–554.Google Scholar
Hanway, J. J. (1963). Growth stages of corn (Zea mays, L.).—Agron. J. 55 pp. 487–492.CrossRefGoogle Scholar
Harris, W. V. (1937). Annual report of the entomologist, 1936.—Rep. Dep. Agric. Tanganyika 1936 pp. 88–94.Google Scholar
Harris, W. V. (1951). Further records of East African termites.—Proc. R. ent. Soc. Lond. (B) 20 pp. 25–28.Google Scholar
Harris, W. V. (1961). Termites: their recognition and control.—187 pp. London, Longmans Green.Google Scholar
Hemingway, J. S. (1957). Effects of population density on yield of maize.— E. Afr. agric. J. 22 pp. 199–202.Google Scholar
Lichtenstein, E. P. & Schulz, K. R. (1961). Effect of soil cultivation, soil surface and water on the persistence of insecticidal residues in soils.— J. econ. Ent. 54 pp. 517–522.CrossRefGoogle Scholar
Lichtenstein, E. P., Mueller, C. H., Myrdal, G. R. & Schulz, K. R. (1962). Vertical distribution and persistence of insecticidal residues in soils as influenced by mode of application and a cover crop.—J. econ. Ent. 55 pp. 215–219.CrossRefGoogle Scholar
Sands, W. A. (1960). Observations on termites destructive to trees and crops.—In Harris, W. V. Termite research in West Africa, pp. 14–63, multigraph. (Unpublished).Google Scholar
Sands, W. A. (1962). The evaluation of insecticides as soil and mound poisons against termites in agriculture and forestry in West Africa.—Bull. ent. Res. 53 pp. 179–192.CrossRefGoogle Scholar
Shrikhande, J. G. & Pathak, A. N. (1948). Earthworms and insects in relation to soil fertility.—Curr. Sci. 17 pp. 327–328.Google Scholar
Thakur, C., Prasad, A. R. & Singh, R. P. (1958). Use of aldrin and dieldrin against termites and their effects on soil fertility.—Indian J. Ent. 19 pp. 155–163.Google Scholar
Weatherley, P. E. (1950). Studies in the water relations of the cotton plant, I. The field measurement of water deficits in leaves.—New Phytol. 49 pp. 81–97.CrossRefGoogle Scholar
Weatherley, P. E. (1951). Studies in the water relations of the cotton plant. II. Diurnal and seasonal variations in relative turgidity and environmental factors.—New Phytol. 50 pp. 36–51.CrossRefGoogle Scholar