Academic Research Journal of Agricultural Science and Research
 

Academic Research Journal of Agricultural Science and Research 

Vol. 5(2), pp. 116-127. March, 2017.

ISSN: 2360-7874 

 DOI: 10.14662/ARJASR2016.059

Full Length Research

Parasitoid Species Diversity and Rates of Parasitism on Maize and Sorghum Stem Borers in the Central Rift Valley of Ethiopia

Abiy Tilahun

Ethiopian Institute of Agricultural Research, Melkassa Agricultural Research center, P.O.Box 436, Adama, Ethiopia. Corresponding author:  Abiy Tilahun.  Ethiopian Institute of Agricultural Research, Melkassa Agricultural Research center, Adama, Ethiopia. E-mail: abiyt2005@gmail.com

Accepted 28 February 2017

Studies were conducted in the Central Rift Valley of Ethiopia to find out stem borer parasitoids species diversity and extent of parasitism, and to determine the stem borer species composition in maize and sorghum. Assessments were done in six districts of eastern Shoa on 120 farmers` fields on maize and sorghum. Observations showed the presence of three stem borer species on maize and sorghum. These were Busseola fusca Fuller (Lepidoptera: Noctuidae), Chilo partellus (Swinhoe) (Lepidoptera: Crambidae) and Sesamia calamistis Hampson (Lepidoptera: Noctuidae). B. fusca and C. partellus were found to be the dominant species consisting of 54% and 45% on maize, and 12.8% and 86.7% on sorghum respectively of the stem borer population. S. calamistis accounted for only less than 0.5%. Larval parasitoids, namely Cotesia flavipes Cameron (Hymenoptera: Braconidae), Dolichogenidea fuscivora Walker (Hymenoptera: Braconidae), and Dolichogenidea polaszeki Walker (Hymenoptera: Braconidae) and pupal parasitoids; Dentichasmias busseolae Heinrich (Hymenoptera: Ichneumonidae) and Pediobius furvus (Gahan) (Hymenoptera: Eulophidae) were recovered from B. fusca and /or C. partellus. Natural parasitism of the above- mentioned parasitoids were assessed at different growth stages of the crops and C. flavipes was found to be the dominant parasitoid species. Exposure of stem borer eggs and recovery of egg parasitoids were made at Melkassa and Arsi Negelle. The results indicated that two egg parasitoids, Telenomus busseolae Gahan (Hymenoptera: Scelionidae) with 62% parasitism and Telenomus thestor (Hymenoptera: Scelionidae) with 76% parasitism were reared from eggs of B. fusca. A hyperparasitoid, Aphanogumus fijiensis was recovered from C. flavipes. Entomopathogens were also isolated from the stem borers.

Key words: stem borer, parasitoids, parasitism, Busseola fusca, Chilo partellus,  Cotesia flavipes

How to cite this article: Tilahun A (2017). Parasitoid Species Diversity and Rates of Parasitism on Maize and Sorghum Stem Borers in the Central Rift Valley of Ethiopia. Acad. Res. J. Agri. Sci. Res. 5(2): 116-127

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