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Interspecific Competition Between Larvae of Sitophilus Oryzae (L.) and Sitotroga Cerealella (Oliv.) in Sorghum Grains

  • M. E. Hassan Shazali
Research Article

Abstract

Competition between larvae of Sitophilus oryzae (L.) and Sitotroga cerealella (Oliv.) within sorghum grains was studied at 30°C and 70% r.h. Newly hatched S. cerealella larvae (0–24 hr) were allowed to infest single sorghum grain having one S. oryzae egg deposited either on the endosperm half or the germ half. S. cerealella larvae were obtained from eggs of the same age as those of the weevil. The moth larvae entered the grain through the germ half. When S. oryzae egg was deposited in the germ half, S. cerealella survival probability was 0.78. However, when S. oryzae egg was deposited in the endosperm half, S. cerealella survival probability was 0.47. When the data for the two sites were combined the probability that the moth larvae will survive competition (P = 0.58) was not significantly different from that of the weevil. Hence, both larvae have similar chances of surviving competition within the sorghum grain.

Key Words

Sitophilus oryzae interspecific competition Sitotroga cerealella sorghum 

Résumé

La compétition entre les larvae de Sitophilus oryzae et le Sitotroga cerealella dans les grains de sorghum, a été etudée a 30°C et a 70% r.h. Des larvae de S. cerealella nouvellement nées ont été permies d’attaquer un grain de sorghum ayan un seul Ouef de S. oryzae placé soit au mileau de l’endosperm soit au mileau de germ. Les S. cerealella larvae sont obtenues des oeufs du même âge comme ceux du charançon. Le Sitotroga est entre dans le grain a travers le demi germe.

Quand l’oeuf de S. oryzae a été déposé dans le demi germe, la probabilité de survivance etait 0.78 tandis qu’en le déposant dans le demi endosperm la probabilité de survivance a demenue 0.47. Quand les deux résultats ont été combinés, la probabilité de survivance est devenue 0.58 ce qui n’était pas beaucoup différant de celui charançon. C’est pourqoui, le deux ont des chances édentiques de survivre la competition au sein du grain de sorghum.

Mots Clés

Sitophilus oryzae competition interspecifique Sitotroga cerealella sorgho 

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Copyright information

© ICIPE 1993

Authors and Affiliations

  • M. E. Hassan Shazali
    • 1
  1. 1.Grain Storage Research UnitShambat Research StationKhartoum NorthSudan

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