**5. Conclusion**

242 Gamma Radiation

or terpenoid odorants. Similarly, the sensory neuron membrane protein of the wild silk moth *Antheraea polyphemus* was most prevalent in neurons and was localized to receptor membrane of the dendrite cilia presumed to perform the role of olfactive conduction

Sensilla chaetica 1 of *R. ferrugineus* are ascribed to mechano-chemoreception in coccinellids,*Semiadalia undecimnotata*, *Coccinella transverguttata* and *P.tsugae* (Jourdon *et al*., 1995; Wipperfurth *et al*.,1987; Broeckling & Salom 2003). In neopseustids, it cannot be excluded that the hair is connected to the considerably elevated socket by a flexible joint membrane and, in this case, the sensilla would be contact mechanoreceptors (Faucheux *et* 

They are resemble in their external sensilla chaetica in *Coccinella transversalis* Fabricius (Coccinellidae) (James, 2001),"chetiform sensilla type I" in *Semiadalia undecimnotata* (Coccinellidae) (Jourdon *et al.,* 1995,"sensilla chaetica type I" in *Agriotes obscurus* Elateridae) (Merivee, 1992) .Some authors treat these also as sensilla trichodea. They are classified, for example, as sensilla trichodea type I in *Carabus fiduciaries saishutoicus* (Carabidae) (Kim &

Sensilla chaetica II could be observed in the antenna of *Cawjeekelia pyongana* (Polydesmida: Paradoxmatidae) (Chung & Moon,2007,2009) and on the labrum of *Synempora andesae* (Neopseustidae),the aporous bifurcate sensilla chaetica could constitute an autapomorphy but would need to be described further in other species of that family (Faucheux 2008).

In the present study the sensilla basiconica 1 and 2 are found on the pedicel and the surface of club. Okada *et al.,* 1992 on the cigarette beetles; *Lasioderma serricorne* and Daly & Ryan, 1979 on the ground beetle, *Nebria brevicollis*, they demonstrated that the wall of these sensilla is perforated by numerous tiny pores. The numerous pores and branched dendrites are considered to be evidence that these basiconica sensilla function as olfactory receptors (Altner & Prillinger, 1980 and Zacharuk,1985).The sensilla basiconica of *Hylobius abietis* were responsive to odours in electrophysiological experiments (Mustaparta, 1975). Moreover, a small groove or depression, not characteristic for mechanoreceptive pegs, at the tip of tiny sensilla basiconica 3 indicate that they propaply function as chemoreceptors (Ploomi *et al.,*

Curculionid, scolytid and coccinellid beetles have been reported to bear antennal sensilla similar to the sensilla basiconica described here (Alm & Hall, 1986; Bland, 1981; Isidoro & Solinas, 1992, Jourdan *et al*., 1995). Non-articulated blunt-tipped basiconica sensilla, which resemble sensilla basiconica 1, 2 of *Bembidion lampros, B. properans* and *Platynus dorsalis* are

Besides the sensory organs abundant cuticular pores, obviously openings of the antennal glands, penetrate the surface of the antennae of *R. Ferrugineus*. Differences in the size and placement of these pores may suggest differences in the function of respective cuticular glands. In some other insects, antennal glands may have enzymatic activity, degrading molecules of pheromones (Taylor *et al.,* 1981). In Chrysomelidae, antennal glands may

A few ultrastructurally obvious effects of irradiation in the features of normal antennal sensilla of *R. Ferrugineus* could be observed*.* Typically seen as shrunken, curved of sensilla

Yamasaki, 1996), and flea beetles (Alticidae) (Ritcey & McIver, 1990).

common on the antennal flagellum of most insects (Ploomi *et al.,* 2003).

produce pheromone (Bartlet *et al*., 1994).

(Rogers *et al*., 2001).

*a*l., 2006).

2003).

The antennal sensilla of unirradiated and irradiated red palm weevile, *Rhynchophorus Ferrugineus* (Oliv.) (Coleoptera; Curculionidae) were investigated by using a scanning electrone microscope. The antenna was composed of three segments; scape, pedicel and flagellum (funicle, club). Four different sensillar types were distinguished. Eleven subtypes, these were; three subtypes of sensilla coeloconica, four subtypes of sensilla trichodea, two subtypes of sensilla basiconica, and two subtypes of sensilla chaetica. The position of these sensilla on the antenna was discussed. These types are used by insects as mechanoreceptor, sex pheromone, aggregation pheromone, olfactory, mate location, thermo-hygroreceptor, and receptivite to heat, and humidity.

There are differences in lengths and diameters of some types of sensilla were recorded as a result of irradiated adult with two doses of gamma rays (15, 20Gy). In the higher dose (20 Gy) more effects of sensilla were recorded for the sensilla chaetica followed by sensilla coeloconica.
