Proximity to fig trees increases medfly populations in citrus orchards

Abstract: To study the influence of adjacent fig trees on captures of medfly adults in thetraps located in citrus orchards and to determine the amount of increase throughout the yearin trap captures considering the distance ranges to the fig trees, twenty-nine cultivated citrusorchards were selected in the island of Ibiza (eastern Spain) and ten traps (tephi-trap withattractant Tripack) were placed per orchard. The population of medfly was sampled weeklyin the 230 traps between April and November for four years, 2005 to 2008, and the amountof captures was compared according to the distance to the fig trees. The overall abundanceand population trend along the year of medfly captures in the island of Ibiza varied amongthe four years sampled, with maximum levels observed in 2007. The population trendshowed an increase between June and August, followed by another increase more importantin September-October. The traps located within a distance of 50 meters from a fig treeshowed a 50-100% increase in total number of flies captured per trap and year, comparedwith traps located at more than 50m. This increase in captures was especially important, inabsolute values, in September and October. All the distance ranges considered (50-75m, 75-100m, 100-150m, 150-200m and >200m) showed always lower captures compared withtraps located at < 50m.