ACULEUS WEAR AND OVIPOSITION IN 4 SPECIES OF TEPHRITIDAE (DIPTERA)

Structural degradation of the aculeus in tephritid flies was studied w ith scanning electron microscopy. We examined the aculei for tip wear or abrasion in Rhagoletis pomonella (Walsh) (60 specimens), R. mendax Curran (19 specimens), Ceratitis capitata (Wiedemann) (38 specimens), and Bactrocera oleae (Gmelin) (8 specimens). More than 70% of the 71 f ield-collected flies showed definite wear of the aculeus tip, whereas < 10% of the 54 specimens preserved following eclosion had some aculeu s tip wear. Fly age, oviposition in preexisting holes, and multiple eg g laying in single oviposition punctures are discussed in relation to aculeus tip wear. This study suggests that structural degradation of t he aculeus caused by oviposition and other activities may be responsib le for alterations in tephritid oviposition behavior.