Active aggregation among sexes in bean flower thrips (Megalurothrips sjostedti) on cowpea (Vigna unguiculata)

Publication Type

Journal Article

Journal Name

Entomologia Experimentalis et Applicata

Name of Author

• Saliou Niassy, International Centre of Insect Physiology and Ecology Nairobi
• Sunday Ekesi, International Centre of Insect Physiology and Ecology Nairobi
• Nguya K. Maniania, International Centre of Insect Physiology and Ecology Nairobi
• Benedict Orindi, International Centre of Insect Physiology and Ecology Nairobi
• Gerald B. Moritz, Martin-Luther-Universität Halle-Wittenberg
• Willem J. de Kogel, Wageningen University & Research
• Sevgan Subramanian, International Centre of Insect Physiology and Ecology Nairobi

Publication Date

1-1-2016

Abstract

Male sexual aggregations are a common territorial, mating-related or resource-based, behaviour observed in diverse organisms, including insects such as thrips. The influence of factors such as plant substrate, time of day, and geographic location on aggregation of thrips is uncertain, therefore we monitored the dispersion of male and female bean flower thrips (BFT), Megalurothrips sjostedti (Trybom) (Thysanoptera: Thripidae), on cowpea, Vigna unguiculata (L.) Walp. (Fabaceae), over three cowpea growth stages and across three cowpea-growing areas of Kenya. Our results indicated that for all the crop growth stages, the density of BFTs varied over the time of day, with higher densities at 10:00, 13:00, and 16:00 hours than at 07:00 hours. Thrips densities did not differ among blocks at the budding stage, but they did at peak flowering and podding stages. Dispersion indices suggested that both male and female BFTs were aggregated. Active male aggregation occurred only on green plant parts and it varied across blocks, crop stages, and locations. Similarly, active female aggregation was observed in peak flowering and podding stages. Such active aggregation indicates a semiochemical or behaviour-mediated aggregation. Identification of such a semiochemical may offer new opportunities for refining monitoring and management strategies for BFT on cowpea, the most important grain legume in sub-Saharan Africa.

Keywords

Aggregation behaviour, Dispersion index, Fabaceae, Grain legumes, Semiochemical, Thripidae, Thysanoptera

Recommended Citation

Niassy, S., Ekesi, S., Maniania, N., Orindi, B., Moritz, G., de Kogel, W., & Subramanian, S. (2016). Active aggregation among sexes in bean flower thrips (Megalurothrips sjostedti) on cowpea (Vigna unguiculata). Entomologia Experimentalis et Applicata, 158 (1), 17-24. https://doi.org/10.1111/eea.12383

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