Evaluation of stable fly traps and attractants in pineapple fields in Costa Rica

Stable flies, Stomoxys calcitrans (L.), have become a significant problem in Costa Rican pineapple fields. Females are attracted to volatiles produced by pineapple vegetative parts turned into the soil after harvest and huge numbers of flies are produced. Management is difficult but traps are a major part of the program. Traps used in the management program and candidate traps configured into attract and kill devices were evaluated in recently harvested pineapple fields. Six traps were spaced 30-m apart down 2 rows (2 complete reps). Traps were placed in the field, serviced every 24 hours after which the first trap in each row was rotated behind the last trap. The Vavoua trap with attractant outperformed all other traps. This was closely followed by the Vavoua trap without attractant. The white plastic bags coated with adhesive followed the Vavoua traps. The Knight Stick trap captured half as many stable flies as the plastic bag trap. However, the Knight Stick traps configured as attract and kill devices captured flies in single digits which indicates that most flies died before reaching the sticky surface of the traps. Knight stick traps are much shorted than the other traps and this limited visibility probably resulted in a smaller fly catch.