Ultrastructural characterization of sensilla and microtrichia on the antenna of female Haematopota pandazisi (Diptera: Tabanidae)

Abstract

The haematophagous females of the cleg fly Haematopota pandazisi (Kröber) (Diptera: Tabanidae) are a common pest in areas inhabited by wild and domestic ungulates in southern Europe, North Africa and Anatolia. A morphological investigation by scanning electron microscopy (SEM) was carried out for the first time on the antennae of females of H. pandazisi, with special attention to the type and distribution of sensilla and microtrichia. The typical brachyceran antenna is divided into three regions: the scape, the pedicel and the flagellum, which is the longest of the three and is composed of four flagellomeres. The scape and pedicel are characterized by only one type of microtrichium and chaetic sensillum, whereas five types of microtrichia and sensilla were identified on the flagellum and classified according to shape and distribution. The sensilla are of the chaetic, clavate, basiconic, trichoid and coeloconic types; the latter with either a basiconic or grooved peg inside. The results obtained in this study were compared to those found in other species in the family Tabanidae and other Diptera, with special attention to haematophagous species.

Ultrastructure of the Olfactory Sensilla across the Antennae and Maxillary Palps of Bactrocera dorsalis (Diptera: Tephritidae)

“…It was found that the antennae and maxillary palps were covered with numerous olfactory sensilla (i.e., ST, SB, and SCo) and non-olfactory sensilla (i.e., SCh and MI). The types, abundance, and distribution of these sensilla are similar to that observed from other Dipteran species, such as Anastrepha serpentine [16], Haematopota pandazisi [8], and B. zonata [17]. These findings were confirmed by previous research [18], except the ST, which we classified into olfactory sensilla based on the multi pores on the surface of the sensilla, observed with the FESEM.…”

“…The SB are mainly distributed on the antennae and maxillary palps, which have been reported in various species such as Hydrotaea chalcogasten [21], Toxotrypana Curvicauda [22], Pseudacteon tricuspis [24], and H. pandazisi [8]. They are identified as olfactory sensilla with ultrastructure characteristics of numerous nano pores present on the surface.…”

“…The olfactory sensilla is characterized as numerous pores on the cuticle, which permit the entry of the semiochemical contacting with the receptors on the dendrite membrane. Even though the sensillum structures have been well studied in a variety of insect species [6][7][8], previous studies have not reported the fine ultrastructure of the sensilla on B. dorsalis antennae and maxillary palps, despite the economic and agricultural importance of this pest.…”

Antennal Morphology and Fine Structure of Flagellar Sensilla in Hippoboscid Flies with Special Reference to Lipoptena fortisetosa (Diptera: Hippoboscidae)

“…Although there are a few electrophysiological studies about the role played by basiconic sensilla, it is known that they are mainly involved in odour detection due to the presence of many pores on the external wall [ 55 ]. The multiporous basiconic sensilla occurring on L. fortisetosa differ from those described in other dipterans [ 34 , 35 , 54 , 56 ], since the ultrastructure shows a reduction in the presence of the wall pores, which occur only in the distal half of the shaft. The limited number of pores on the basiconic walls could be due to the perception of the host odours which is activated just when the parasite is approaching the host at short–medium distances.…”

“…In particular, in H. equina the microtrichia are present also on the internal surface of the antennal fossa, lending support to this hypothesized role. Recently, six types of microtrichia, including branched ones, have been detected also on the flagellum of the tabanid fly Haematopota pandazisi (Krober, 1936) by Pezzi et al [ 35 ], who postulated the role of these structures, together with different kinds of sensilla, in the sensory perception.…”