Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-11-25T05:27:20.706Z Has data issue: false hasContentIssue false
  • English
  • Français

Predicting the severity of Spodoptera exempta (Lepidoptera: Noctuidae) outbreak seasons in Tanzania

Published online by Cambridge University Press:  10 July 2009

A.W. Harvey  and
G.A. Mallya
A.W. Harvey*
Affiliation:
Ministry of Agriculture, Arusha, Tanzania
G.A. Mallya
Affiliation:
Ministry of Agriculture, Arusha, Tanzania
*
A. W. Harvey, Natural Resources Institute, Chatham Maritime, Chatham, Kent ME4 4TB, UK.
Get access Rights & Permissions [Opens in a new window]

Abstract

Outbreaks of the African armyworm, Spodoptera exempta (Walker), in East Africa follow a seasonal pattern related to the movement of the inter-tropical convergence zone. The season typically begins in central Tanzania with primary outbreaks that coincide with the arrival of the rains. An analysis of 27 years' light trap records shows a high negative correlation between the total number of moths caught by light traps during the season over the whole country and the number of rain days during November in central Tanzania. Out of the 27 seasons, 22 could have been correctly predicted as ‘light’ or ‘severe’, using the November rainfall at one station, Dodoma, in time to give two months' warning before the peak of the season.

Type
Original Articles
Information
Bulletin of Entomological Research , Volume 85 , Issue 4 , December 1995 , pp. 479 - 487
Copyright
Copyright © Cambridge University Press 1995

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

Birch, H.F. (1958) The effect of soil drying on humus decomposition and nitrogen availability. Plant and Soil 10, 9–31.CrossRefGoogle Scholar
Brown, E.S., Betts, E. & Rainey, R.C. (1969) Seasonal changes in distribution of African armyworm, Spodoptera exempta (Walk.) (Lepidoptera, Noctuidae), with special reference to eastern Africa. Bulletin of Entomological Research 58, 661–728.CrossRefGoogle Scholar
Faure, J.C. (1943) Phase variation in the armyworm Laphygma exempta (Walk.). Science Bulletin, Department of Agriculture and Forestry, Union of South Africa. No. 234, 17 pp.Google Scholar
Haggis, M.J. (1986) Distribution of the African armyworm, Spodoptera exempta (Walker) (Lepidoptera: Noctuidae), and the frequency of larval outbreaks in Africa and Arabia. Bulletin of Entomological Research 76, 151–170.CrossRefGoogle Scholar
Hattingh, C.C. (1941) The biology and ecology of the armyworm (Laphygma exempta) and its control in South Africa. Science Bulletin, Department of Agriculture and Forestry, Union of South Africa No. 217, 50 pp.Google Scholar
Logan, J.A. & Allen, J.C. (1992) Non-linear dynamics and chaos in insect populations. Annual Review of Entomology 37, 455–477.CrossRefGoogle Scholar
NOAA (National Oceanographic and Atmospheric Administration) (1992) Climate Diagnostics Bulletin: 05 1992 (92/5). Washington.Google Scholar
Odiyo, P.O. (1981) Developements of the first outbreaks of the African armyworm, Spodoptera exempta (Walk.) between Kenya and Tanzania during the “off-season” months of July-December. Insect Science and its Application 1, 305–318.Google Scholar
Pedgley, D.E., Page, W.W., Mushi, A., Odiyo, P., Amisi, J., Dewhurst, C.F., Dunstan, W.R., Fishpool, L.D.C., Harvey, A.W., Megenasa, T. & Rose, D.J.W. (1989) Onset and spread of an African armyworm upsurge. Ecological Entomology 14, 311–333.CrossRefGoogle Scholar
Rasmusson, E.M. & Carpenter, T.H. (1983) The relationship between eastern equatorial Pacific sea surface temperature and surface wind fields associated with the Southern Oscillation/El Niño. Monthly Weather Review 111, 517–528.2.0.CO;2>CrossRefGoogle Scholar
Roffey, J. (1972) Locusta outbreaks in the Phillipines. Acrida 1, 177–188.Google Scholar
Ropelewski, C.F. & Halpert, M.S. (1987) Global and regional scale precipitation patterns associated with the El Niño/southern oscillation. Monthly Weather Review 115, 1606–1626.2.0.CO;2>CrossRefGoogle Scholar
Rose, D.J.W. (1975) Field development and quality changes in successive generations of Spodoptera exempta Wlk., the African armyworm. Journal of Applied Ecology 12, 727–739.CrossRefGoogle Scholar
Rose, D.J.W. (1979) The significance of low-density populations of the African armyworm Spodoptera exempta (Walker) (Lepidoptera: Noctuidae). Philosophical Transactions of the Royal Society of London (B) 287, 393–402.Google Scholar
Rose, D.J.W., Page, W.W., Dewhurst, C.F., Riley, J.R., Reynolds, D.R., Pedgley, D.E. & Tucker, M.R. (1985) Downwind migration of the African armyworm, Spodoptera exempta, studied by mark-and-recapture and by radar. Ecological Entomology 10, 299–313.CrossRefGoogle Scholar
Symmons, P. (1960) The effect of climate and weather on the numbers of the Red Locust, Nomadacris septemfasciata (Serv.) in the Rukwa Valley outbreak area. Bulletin of Entomological Research 50, 507–521.CrossRefGoogle Scholar
Taylor, R.A.J. (1986) Time-series analysis of numbers of Lepidoptera caught at light traps in East Africa, and the effect of moonlight on trap efficiency. Bulletin of Entomological Research 76, 593–606.CrossRefGoogle Scholar
Tucker, M.R. (1984a) Possible sources of outbreaks of the armyworm, Spodoptera exempta (Walk.) (Lepidoptera: Noctuidae), in East Africa at the beginning of the season. Bulletin of Entomological Research 74, 599–607.CrossRefGoogle Scholar
Tucker, M.R. (1984b) Forecasting the severity of armyworm seasons in East Africa from early season rainfall. Insect Science and its Application 5, 51–55.Google Scholar
Tucker, M.R., Mwandoto, S. & Pedgley, D.E. (1982) Further evidence for windborne movement of armyworm moths, Spodoptera exempta in East Africa. Ecological Entomology 7, 463–473.CrossRefGoogle Scholar
White, T.C.R. (1975) Weather, food and plagues of locusts. Oecologia 22, 119–134CrossRefGoogle Scholar