Mobility of olive fruit fly (Diptera: Tephritidae) late third instars and teneral adults in test arenas

The mobility of olive fruit fly, Bactrocera oleae (Rossi), late third instars before pupation, teneral adults before flight, and mature adults restricted from flight were studied under mulches in greenhouse cage tests, in horizontal pipes, vertical bottles and pipes filled with sand, and by observation on smooth laboratory surfaces. Percentage adults emerging from pupae and percentage adult females that escaped soil, fabric, and paper mulches over a soil or sand substrate ranged from 63 to 83, and 40-53%, respectively. Percentage adults emerging from pupae and percentage adult females that walked through the open interior of 1.52-6.10-m horizontal pipes of 1.5-2.0-cm inner diameter ranged from 57 to 81, and 27-61%, respectively. Percentage adults emerging from pupae that escaped through sand depths of 2.5-10.2, and 12.7-20.3 cm, ranged from 68 to 87, and 12-88%; and percentage adult females that escaped ranged from 46 to 58, and 38-70%, respectively. In 15.4-cm-inner-diameter pipes filled with different heights of sand, the highest percentage of the total number of adults that emerged in the control were found from 0 to 20.3 cm, and ranged from 37 to 71%. Ten to 47% of adults were found from 20.3 cm to below the surface, and 6-21% escaped to the top of 20.3-50.8 cm high sand columns. In column heights of 55.9 and 61 cm, pressures at the bottom caused by the weight of the sand above were 91.4 and 99.7 g/cm(2), respectively, and a mean of <1 adult escaped to the top. Before pupation, the late third instars were found to travel continuously for 6.9 h over 23.9 m at a speed of 6.0 cm per min, when placed on a smooth surface, at 22.2°C. Teneral females and males that could not fly, made ≍7 stops totaling 11-13 min, walked at a speed of 57-62 cm per min, and began a rest period of 83-84 min duration, at 85-89 min before flight. Males walked a distance of 13.1 m in 22 min, which was greater than females that walked for 9.6 m in 17 min, at 20-22°C and 35% RH. The mobility of the third instars and the teneral adults is discussed in relation to potential control techniques in olive orchards.