Niassy S., Maniania N.K., Subramanian S., Gitonga L.M., Ekesi S.
International Centre of Insect Physiology and Ecology (ICIPE), PO Box 30772-00100, Nairobi, Kenya; Jomo Kenyatta University of Agriculture and Technology (JKUAT), PO Box 62000, Nairobi, Kenya
Niassy, S., International Centre of Insect Physiology and Ecology (ICIPE), PO Box 30772-00100, Nairobi, Kenya, Jomo Kenyatta University of Agriculture and Technology (JKUAT), PO Box 62000, Nairobi, Kenya; Maniania, N.K., International Centre of Insect Physiology and Ecology (ICIPE), PO Box 30772-00100, Nairobi, Kenya; Subramanian, S., International Centre of Insect Physiology and Ecology (ICIPE), PO Box 30772-00100, Nairobi, Kenya; Gitonga, L.M., Jomo Kenyatta University of Agriculture and Technology (JKUAT), PO Box 62000, Nairobi, Kenya; Ekesi, S., International Centre of Insect Physiology and Ecology (ICIPE), PO Box 30772-00100, Nairobi, Kenya
The performance of an autoinoculation device was evaluated in field cage experiments for control of Western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), in French bean, Phaseolus vulgaris L. var. Samantha (Fabaceae). Treatments consisted of a fungus-treated device with and without semiochemical (Lurem-TR), and a fungus-free device as control; the fungus used was Metarhizium anisopliae (Metchnikoff) Sorokin (Hypocreales: Clavicipitaceae). The overall mean number of conidia acquired by a single insect was higher in the fungus-treated semiochemical-baited device than in the device without semiochemical: 5.0±0.6×10 4 vs. 2.2±0.4×10 4 conidia per insect. The overall thrips mortality was also higher in the semiochemical-baited device than in the device without the semiochemical: 59.3±3.9 vs. 41.7±3.5%. Conidial viability was not affected in the M. anisopliae-treated device without semiochemicals, 7days after treatment, whereas it was considerably decreased - from 81.0±1.3 to 6.5±1.1%, 2 and 7days post-inoculation - in the M. anisopliae-treated semiochemical-baited device. Thrips mortality was positively correlated with M. anisopliae conidial viability, and conidial viability was negatively correlated with conidial acquisition. This suggests that the semiochemical volatiles reduced the conidial viability, which in turn resulted in significant reduction in thrips mortality, despite the highest conidial acquisition in the semiochemical-baited fungus-treated device. Thrips density per plant was significantly reduced in both fungus-treated treatments (with semiochemical: 8.7±1.7 adults per plant; without semiochemical: 6.6±1.4 adults per plant) compared with the fungus-free control (19.8±2.6 adults per plant). These results demonstrate the potential for an autoinoculation device strategy for the control of thrips, particularly in screenhouses. © 2011 The Authors. Entomologia Experimentalis et Applicata © 2011 The Netherlands Entomological Society.
bait; disease treatment; fungus; inoculation; legume; mortality; performance assessment; pest control; semiochemical; thrips; volatile substance; Clavicipitaceae; Fabaceae; Frankliniella; Frankliniella occidentalis; Fungi; Hexapoda; Hypocreales; Metarhizium anisopliae; Phaseolus vulgaris; Thripidae; Thysanoptera
