Hostname: page-component-78c5997874-g7gxr Total loading time: 0 Render date: 2024-11-01T18:02:15.017Z Has data issue: false hasContentIssue false

Intraspecific competition in larvae of the larger grain borer, Prostephanus truncatus (Horn) within maize grains

Published online by Cambridge University Press:  19 September 2011

Kwame A. Vowotor*
Affiliation:
Food Research Institute (CSIR), P. O. Box M20, Accra, Ghana
William G. Meikle
Affiliation:
Plant Health Management Division, International Institute of Tropical Agriculture BP 08–0932, Cotonou, Bénin
Jonathan N. Ayertey
Affiliation:
University of Ghana, Crop Science Department P. O. Box 44, Legon, Accra, Ghana
Christian Borgemeister
Affiliation:
Plant Health Management Division, International Institute of Tropical Agriculture BP 08–0932, Cotonou, Bénin
Richard H. Markham
Affiliation:
Plant Health Management Division, International Institute of Tropical Agriculture BP 08–0932, Cotonou, Bénin
Get access

Abstract

The effects of egg clutch size on development and survivorship of the larger grain borer, Prostephanus truncatus (Horn) (Col.: Bostrichidae) on maize were measured in the laboratory using single grains of the white maize variety, TZSR-W, at 30 ± 2°C and 70 ± 5% RH. Varying numbers of P. truncatus eggs (1, 2, 4, 8, or 16) were introduced into a hole drilled into a single maize grain. Destructive sampling was used at regular intervals to obtain data on immature developmental parameters, the location of immatures within the grain and the weight and sex of any emerged adults. First instars fed mainly on the floury endosperm tissue whereas the second and third instars preferred the germ tissue. Mortality due to competition was highest in first instars. At high initial densities (> 4 per kernel), some P. truncatus larvae reduced competition by moving out of the grain. A maximum of 6 adults emerged from a single grain. The mean number of adults that emerged per grain for initial egg densities of 8 and 16 were 3.3 and 3.5, respectively. Prostephanus truncatus adult weight at emergence was not significantly influenced by initial egg density except in the case of clutch size 16. The sex ratio of emerged adults was also unaffected by competition, and was always 1:1. Complete developmental period within grains ranged between 28 and 32 days.

Résumé

Les effets de la taille de la fournée d'oeufs déposés par le grand capucin, Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), sur son développement et sa survie, ont été étudiés au laboratoire sur les graines isolées du maïs blanc, variété TZSR-W, à une température de 30 ± 2°C et une humidité relative de 70 ± 5%. Un nombre différent d'oeufs (1,2, 4,8 ou 16) de P. truncatus a été introduit dans un trou foré dans chaque graine de maïs. Une méthode destructive a été utilisée à des intervalles réguliers pour recueillir les données sur les paramètres de développement larvaire, la localisation des stades immatures à l'intérieur de la graine ainsi que le poids et le sexe des adultes émergés. Les premiers stades larvaires se nourrissaient principalement de l'endosperme tandis que les second et troisième stades larvaires préféraient se nourrir sur le germe. La mortalité due à la compétition nutritionnelle était très élevée chez les larves du premier stade. A des densités initiales élevées (> 4 individus par grain), certaines larves de P. truncatus évitaient cette compétition en sortant de la graine. Un maximum de 6 adultes a émergé d'une seule graine. Avec des densités initiales de 8 et 16 oeufs par graine, la moyenne d'adultes émergés étaient respectivement de 3,3 et 3,5. Le poids moyen des adultes à l'émergence n'était pas significativement influencé par la densité initiale d'oeufs, sauf dans le cas de 16 oeufs par graine. Le rapport de mâles et femelles adultes n'était pas affecté par la compétition et il est resté tout le temps de 1:1. Le développement complet de l'insecte à l'intérieur des graines se rangeait entre 28 et 32 jours.

Type
Research Articles
Copyright
Copyright © ICIPE 1998

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

Abacus Concepts Inc. (1992) Stat View Statistical Package, Abacus Concepts Inc., Berkeley, CA, USA.Google Scholar
Anderson, F. S. (1961) Effect of density on animal sex ratio. Oikos 12, 116.CrossRefGoogle Scholar
AOAC (1984) Official methods of analysis. Association of Official Analytical Chemists. 13th edition. Washington DC, USA.Google Scholar
Ashby, K. R. (1961) The population dynamics of Cryptolcstcs ferruginous (Stephens) in flour and on Manitoba wheat. Bull. Entomol. Res. 52, 363379.Google Scholar
Crombie, A. C. (1944) On intraspecific and interspecific competition in larvae of graminivorous insects, J. Exp. Biol. 20, 135151.CrossRefGoogle Scholar
Dunstan, W. R. and Magazini, I. A. (1981) Outbreaks and new records. Tanzania. The larger grain borer on stored products. FAO Plant Prot. Bull. 29, 8081.Google Scholar
Godfray, H. C. J. (1986) Clutch size in a leaf mining fly (Pegomya nigritarsis: Anthomyiidae). Ecol. Entomol. 11, 7581.CrossRefGoogle Scholar
Hodges, R. J. (1982) A review of the biology and control of the greater grain borer Prosteplmmts truncatus (Horn) (Col.: Bostrichidae). Trop. Stored Prod. Info. 43, 39.Google Scholar
Hodges, R. J. (1986) The biology and control of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae). A destructive storage pest with an increasing range, J. stored Prod. Res. 22, 114.CrossRefGoogle Scholar
Hodges, R. J., Cork, A. and Hall, D. R. (1984) Aggregation pheromones for monitoring the greater grain borer Prostephanus truncatus. British Crop Prot. Conf.— Pests and Diseases. Brighton, Nov. 1984, pp. 255260.Google Scholar
Hodges, R. J., Dunstan, W. R., Magazini, I. and Golob, P. (1983) An outbreak of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae) in East Africa. Prot. Ecol. 5, 183194.Google Scholar
Klomp, H. (1964) Intraspecific competition and the regulation of insects numbers. Annu. Rev. Entomol. 9, 1740.CrossRefGoogle Scholar
Li, L. (1988) Behavioural ecology and life history evolution in the larger grain borer Prostephanus truncatus (Horn). PhD thesis, University of Reading, UK. 229 pp.Google Scholar
Markham, R. H., Meikle, W. G., Adda, C., Djomamou, B. and Borgemeister, C. (1996) Progress towards integration of control strategies in West Africa, pp. 81100. In Proc. East and Centr. Africa Storage Pest Management Workshop Naivasha, Kenya. April 14–19, 1996 (Edited by G. Hill and G. Farrell). CAB Wallingford, UK.Google Scholar
Markham, R. H., Wright, V. F. and Rios Ibarra, R. M. (1991) A selective review of research on Prostephanus truncatus (Col.: Bostrichidae) with an annotated and updated bibliography. Ceiba 32, 190.Google Scholar
Shires, S. W. (1980) Influence of temperature and humidity on survival, development period and ad ult sex ratio in Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae). J. Stored Prod. Res. 15, 510.CrossRefGoogle Scholar
Shires, S. W. and McCarthy, S. (1976) A character for sexing live adults of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae). J. stored Prod. Res. 12, 273275.Google Scholar
Snyman, A. (1949) The influence of population densities on the development and oviposition of Plodia interpunctella Hübn. J. Entomol. Soc. S. Africa 12, 137171.Google Scholar
Subramanyam, Bh., Cutkomp, L. K. and Darveaux, B. A. (1985) A new character for identifying larval instars of Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae). J. stored Prod. Res. 21, 101104.Google Scholar
Ullyett, G. C and Merwe, J. S. (1947) Some factors influencing population growth of Ephestia kuehniella Zeil. J. Entomol. Soc. S. Africa 10, 4663.Google Scholar