Preliminary results of bait station evaluation for medfly in a citrus orchard in Costa Rica

The objective of the present study was to test the effectiveness of bait stations for suppression of medfly (Ceratitis capitata, Wied.) populations. The evaluation was carried out at La Guacima orchard, a 1.4 ha sweet orange orchard, from January 20 to March 17, 2005. Fifty bait stations were placed every week for 24 hrs in the experimental orchard. The data obtained were compared with the medfly population at a mixed fruit orchard (Vargas Orchard) of 0.4 ha located 1.0 km to the east of the first one, and with another 0.8 ha citrus orchard (Ruiz Orchard) located in Santa Ana where no control measures were applied. Fortyone medflies were captured at La Guacima Orchard, 314 at Vargas Orchard and 552 at Ruiz Orchard. Also captured were 3 Anastrepha ludens at La Guacima Orchard, 15 A. ludens and 1 A. fraterculus at Vargas Orchard and 8 A. ludens and 1 A. obliqua at Ruiz Orchard. The fly per trap per day index (FTD) at La Guacima Orchard oscillated between 0.04 and 0.2, and there were no medfly larvae in 8 samples of 50 mature oranges analyzed weekly. At Vargas Orchard, the FTD index oscillated between 8.5 and 20.5 and at Ruiz Orchard between 0.16 and 35.16. The results show the potential of the bait stations to control medfly populations in a sweet orange orchard during the dry season, period when the medfly population density in Costa Rica increases. (author)