Canadian Forest Service Publications

Effect of post-harvested rice conservation on Sitophilus oryzae L. in Côte d'Ivoire. 2016. Doumbia, M.; Douan, B.G.; Martel, V.; Kwadjo, K.E.; Kra, D.K.; Dagnogo, M. Int. J. Farm. Alli. Sci. 5: 503-508.

Year: 2016

Available from: Laurentian Forestry Centre

Catalog ID: 37870

Language: English

CFS Availability: PDF (request by e-mail)

Abstract

Harvested rice in rural area in Côte d’Ivoire is stored under four main modalities: Husked and Not Parboiled Rice (HNPR), Husked and Parboiled Rice (HPR), Not Husked and Not Parboiled Rice (NHNPR) and Not Husked and Parboiled Rice (NHPR). The effect of rice treatments on S. oryzae population dynamics was thus assessed based on parameters such as the number of living individuals counted at each observation period, the evolution of the population biomass, the evolution of the cumulative percentage of mortality over time and depending on sex. Laboratory studies on some population dynamics parameters of Sitophilus oryzae L. (Coleoptera : Curculionidae) depending on these four rice conservation modalities, showed that only the (HNPR) treatment allowed a significant population growth and an important increase of the living biomass of this pest. In addition, high S. oryzae mortality rates were observed when the insect was reared on the three other rice conservation modalities. Besides, more than 50% of insect parents died during the first forty five days of the tests when the insects were reared on HPR, NHNPR and NHPR. These results will allow the conception of non-chemical management methods based on the bioecology of this pest.

Plain Language Summary

This study demonstrated that the rice weevil had a better survival rate when feeding on stored rice that had been husked and not steamed. The researchers studied weevil development in conjunction with four rice storage methods in the Ivory Coast. In addition to the method already mentioned, the rice storage methods studied were husked and steamed, not husked and not steamed, and not husked but steamed. The researchers observed that with the last three methods, half of the adult weevils died within the first 45 days of the test.

The purpose of this project was to study the effect of rice storage methods on the dynamics of rice weevil populations. These results will make it possible to develop biological control strategies against this pest using the insect’s own biology.

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