Differences in antennal sensillae of male and female peach fruit flies in relation to hosts.

Antennal sensillae of male and female peach fruit flies, Bactrocera zonata (Saunders) (Diptera: Tephritidae), obtained from three different host fruit species (guava, Psidium guajava L. (Myrtales: Myrtaceae); peach, Prunus persica (L.) Stokes (Rosales: Rosaceae); and orange, Citrus sinensis (L.) Osbeck (Sapindales: Rutaceae)), were studied with scanning electron microscopy. This study was carried out to describe the different types of sensillae present on the three antennal segments (scape, pedicel, and flagellum or funiculus) of both sexes of B. zonata on different host fruit. The antennal segments of females tended to be larger than those of males feeding on peach and guava fruit. On orange, both sexes were similar (no significant differences were found). The first two antennal segments, scape and pedicel, are reinforced by some bristles and have different types of sensillae, including trichoid I, II, S; basiconic II; and sensilla chaetica in different numbers on different host fruit species. Numerous microtrichia, as well as trichoid (I, II), basiconic (I), clavate, and coeloconic (I, II) sensillae were observed on the funiculus with a great variation in number and length. As a result of feeding on different hosts, differences were found between sexes and some plasticity in size, number, distribution, and position of some sensillae, including trichoid, basiconic, chaetica, and clavate on the antennae of the female B. zonata. These sensillae were significantly larger in females. Also, some morphological and morphemetric differences have been found according to their feeding on different host fruit.

Ultrastructure of the antennal sensillae of male and female peach fruit fly, Bactrocera zonata.

Antennal morphology and funicular sensillae of male and female peach fruit flies, Bactrocera zonata (Saunders) (Diptera: Tephritidae), were studied with scanning electron microscopy (SEM). This study focused on the sensillae found on the antennal segments (scape, pedicel, and flagellum or funiculus that bears the arista) of B. zonata. Antennal segments of females tended to be larger than those of the males. The first two antennal segments, scape and pedicel, were heavily covered with microtrichia and bear bristles. Numerous microtrichia as well as trichoid (I, II), basiconic, clavate, and coeloconic sensillae were observed on the funiculus. SEM studies showed some differences in size and also in position of some sensillae on the antennae of the females of B. zonata. The sensillae found on the funiculus, such as trichoid and basiconic sensillae, were significantly larger in females.