Depth of Pupation in Four Species of Fruit Flies (Diptera: Tephritidae) in Sand With and Without Moisture

Abstract

Larvae (late 3rd instars) of Bactrocera dorsalis (Hendel), B. cucurbitae (Coquillett), B. latifrons (Hendel), and Ceratitis capitata (Weidemann) were placed in either wet or dry sand for pupation. In dry sand, 91.1, 93.6, and 97.2% of the pupation by B. latifrons,B. cucurbitae, and B. dorsalis , respectively, occurred at a depth of 0 -5.5 mm. The remainder of the Bactrocera spp. pupated within 11 mm of the surface. More C. capitata (54.0%) pupated at 5.5-11 mm than at 0-5.5 mm (42.5%) and 3.5% moved down to 27.5 mm. In wet sand (5% water by weight), 95.5% of al14 species pupated at depths of 0-27.5 mm. Mortality of pupae was greatest in the dry sand at 0-5.5 mm. Cumulative mortality was 50% greater in dry sand than in wet sand. This indicates that both pupation depth and survival are affected by the moisture content of the sand. However, C. capitata is better adapted to the dry conditions than are the Bactrocera spp.