Last Updated on July 23, 2026 by Olasunkanmi Olajide
By Femi Dansu
The Institute of Food Security, Environmental Resources and Agricultural Research (IFSERAR), Federal University of Agriculture, Abeokuta (FUNAAB), has showcased promising research findings on the use of botanical extracts as sustainable alternatives to synthetic insecticides for controlling the African rice gall midge. The research was presented during the Institute’s July Monthly Seminar, held on July 22, 2026, at the IFSERAR Laboratory.
Delivering the seminar, titled “Harnessing the Biopesticidal Potential of Selected Botanical Extracts Against African Rice Gall Midge,” Dr. Busola Ayangbemi highlighted the destructive impact of the African rice gall midge (Orseolia oryzivora Harris and Gagné), an indigenous insect pest that attacks both irrigated and rain-fed lowland rice fields across Africa. She noted that the pest, which causes the characteristic “silver shoot” or “onion leaf shoot” symptoms, could result in yield losses of up to 100 per cent in endemic areas.
Presenting the findings of the study, Dr. Ayangbemi explained that ten botanical extracts were evaluated as environmentally friendly alternatives to conventional insecticides. She disclosed that Ageratum conyzoides exhibited the highest insecticidal activity, significantly reducing tiller infestation and pest damage while enhancing plant growth, increasing the number of productive tillers and panicles, and substantially improving grain yield. Chromolaena odorata ranked second in effectiveness, followed by Ocimum gratissimum.
The researcher further revealed that soaking rice seeds in the botanical extracts before planting provided systemic protection against the African rice gall midge. According to her, rice plants raised from treated seeds recorded significantly lower tiller infestation than untreated controls, demonstrating that the bioactive compounds remained effective during the early stages of crop establishment. She added that Ageratum conyzoides and Chromolaena odorata produced the most remarkable protective effects.
Dr. Ayangbemi also noted that varietal resistance significantly influenced treatment performance. She explained that the moderately resistant rice variety, BW 348-1, consistently recorded lower infestation levels and higher grain yields than the susceptible ITA 306, indicating that integrating host plant resistance with botanical seed treatment offers enhanced protection against the African rice gall midge.
The seminar concluded that selected botanical extracts possess considerable biopesticidal potential and could serve as environmentally friendly alternatives to synthetic insecticides. Participants noted that incorporating Ageratum conyzoides, Chromolaena odorata and Ocimum gratissimum into integrated pest management strategies would promote sustainable rice production, strengthen food security and support environmental sustainability across Africa.
