version ISSN 0377-9424
HILJE, Luko and STANSLY, Phil A.. Influence of ground covers on hostplant selection by Bemisia tabaci, under greenhouse conditions. Agron. Costarricense [online]. 2011, vol.35, n.2, pp. 89-96. ISSN 0377-9424.
Even though several ground covers, either inert or living, can reduce B. tabaci adult numbers arriving to tomato plants, the specific mechanism by which they act remains unknown. Therefore, an experiment was conducted in a greenhouse in Turrialba, Costa Rica, to determine B. tabaci response to both inert (green metal, and silver and yellow plastics) and living covers: perennial peanuts (Arachis pintoi, Fabaceae), “cinquillo” (Drymaria cordata, Caryophyllaceae) and coriander (Coriandrum sativum, Umbelliferae). These were compared to a control (bare soil). There were 4 replicates of each treatment. Each cover was prepared in a large pot, surrounding a 15-cm tall tomato seedling. Pots were distributed on the greenhouse floor, 40 cm apart. Each experiment was replicated over 4 consecutive days, with treatments being randomized each time. A split-plot design was used, with ground covers as the main plot and dates as subplots. On the eve of each replicate, 1200 B. tabaci adults (A biotype) were released into the experimental area, and the next day adults on both the tomato plants and the respective covers were counted. Adult numbers were by far highest on tomato plants sown in bare soil (p<0.01). Furthermore, their numbers did not differ among ground covers, either living or inert (p>0.05). Despite all covers interfering with insect’s ability to locate tomato plants, the underlying specific mechanism differed depending on each cover’s nature, except among living covers, which seemed to share the same mechanism
Keywords : Ground covers; host-plant selection; Bemisia tabaci; tomatoes; Costa Rica.