Submitted to: Studia Dipterologica
Publication Type: Peer reviewed journal
Publication Acceptance Date: 2/15/2004
Publication Date: 11/15/2004
Citation: Sivinski, J.M., Klug, H., Shapiro, J.P., Lane, J., Mankin, R.W., 2004. Ultra violet reflectance on the heads and wings of Anastrepha suspensa (Loew) and Certatitis capitata (Wiedemann) (Diptera: Tephritidae). Studia Dipterologia. 11:313-322. Interpretive Summary: Fruit flies, including the Caribbean and Mediterranean fruit flies, are among the world¿s most important pests of fruit and vegetables and are often suppressed or eradicated through ¿Sterile Insect Technique¿ (=SIT). The success of SIT depends on the released males being sexually acceptable to wild female flies and detailed knowledge of the pests¿ courtship behavior is required to maintain the sexual attractiveness of the mass-reared flies. Scientists at the Center for Medical, Agricultural and Veterinary Entomology (Gainesville, Florida) examined the visual courtship signals of Caribbean and Mediterranean fruit flies and determined that in certain cases males bear previously unrecognized patches of ultraviolet coloration, visible to female insects but invisible to human observers. This information will eventually help decipher the signals males send to mates through the movement of colored and patterned surfaces and ultimately guide the process of SIT. Plans are underway to examine more fruit fly species for ultraviolet and other visual courtship signals.
Technical Abstract: Tephritid fruit flies have a number of behaviors and structures suggestive of visual sexual and agonistic displays. These include elaborate and stylized movements of patterned wings in both the Caribbean fruit fly (Anastrepha suspensa [Loew]) and the Mediterranean fruit fly (Ceratitis capitata [Wiedemann]) and the white, sexually dimorphic, face of male C. capitata. Ultraviolet (=UV) reflections may play a previously undescribed role in these displays, particularly since all examined tephritid species exhibit a peak of spectral sensitivity at the UV wavelength of 365 nm. The faces and wings of both male and female A. suspensa and C. capitata were compared for reflectance at 365 nm. Male C. capitata faces reflected more UV than those of females, but the faces of A. suspensa were monomorphic. UV reflectance of the wings depended on the reflectance of the background, presumably because portions of the wing are translucent. There were significant sexual differences in UV translucency (=reflectance) in both species when observed against a highly reflective background. Male C. capitata and female A. suspensa wings were UV- brighter than those of their opposite sexes. These two directions in sexual dimorphism add further ambiguity to the interpretation of the function(s) of wing patterns in the Tephritidae. A larger sample of more complete descriptions of purported visual signals, including more UV measurements, are needed to better test the several hypotheses advanced to explain their evolution.