**3.6.2 The effects of the dose rate 20 Gray**

### **3.6.2.1 Sensilla coeloconica**

#### **3.6.2.1.1 Sensilla coeloconica 1**

The sensilla appeared less in number but very tall. The fingers- like processes of the sensilla became very attachment and inflected around each other. The length measures about 35 µm and the diameter about 9.5 µm (Fig.6A).

#### **3.6.2.1.2 Sensilla coeloconica 2**

The fingers-like processes of sensilla fused into two groups. In each group these processes are less in number and broad basally which gradually decrease in diameter until reach to fine tipe. The sensilla arise straight and make 450C with the antennal shaft. Itיs length measures from about 28.8 to 30 µm and the diameter about 7 µm (Fig.6B).

#### **3.6.2.1.3 Sensilla coeloconica 3**

The fusion of finger- like processes of the sensilla disappeared from about the half length of most sensilla. Some of the separated processes were diverged, extend vertically on the antennal shaft, while the others were converged and form an angle of around 40 0C with the antennal shaft. The sensilla measures about 14 µm in length and about 2 µm in diameter (Fig.6D).

#### **3.6.2.2 Sensilla chaetica**

#### **3.6.2.2.1 Sensilla chaetica** 1

The S. chaetica 1 on the lateral side of the club arises from a wide sachet and appeared increased in diameter in the half length reached to about 7 µm. The two branches of the sensilla are not equal in length. The sensilla ranged in length from about 31.5 to 35 µm and about 3.5 µm in diameter (Fig.7A).While the S. chaetica 1 on the surface of club gathered into dense collections and mostly destroyed. Some of the collected sensilla were mostly fused with loss of parts of each sensillum (Fig.7C).In other collection, the sensilla were markedly shrunken and curved into different directions.

#### **3.6.2.2.2 Sensilla chaetica 2**

The sensilla were few in number, markedly shrunken. The part near to the socket was swollen, while the apical part disappeared (Fig.7B).

Fig. 6. SEM photomicrographs of irradiated adult antenna of *Rhynchophorus Ferrugineus* with 20 Gy of gamma rays. (A): Tall sensilla coeloconic1 (C1) on the scape, (B): Sensilla coeloconic 2 (C2) on the pedicel, (C): Sensilla basiconic 1 (B1) on the ventral side between scape and pedicel and (D): Sensilla coeloconic 3 (C3) on the funicel. [Scale bars indicate 50 µm (A), 10 µm (B) and 20 µm (C, D), respectively]

#### **3.6.2.3 Sensilla basiconica 1**

238 Gamma Radiation

The sensilla became shorter, swollen near to the base. The apical part of the sensilla is

The sensilla fewer in number and thickened out, shrunken and thinner near to the tip; the bifurcated end appears located more towards the apex. The length measures from about 6.5

The sensilla appeared less in number but very tall. The fingers- like processes of the sensilla became very attachment and inflected around each other. The length measures about 35 µm

The fingers-like processes of sensilla fused into two groups. In each group these processes are less in number and broad basally which gradually decrease in diameter until reach to fine tipe. The sensilla arise straight and make 450C with the antennal shaft. Itיs length

The fusion of finger- like processes of the sensilla disappeared from about the half length of most sensilla. Some of the separated processes were diverged, extend vertically on the antennal shaft, while the others were converged and form an angle of around 40 0C with the antennal shaft. The sensilla measures about 14 µm in length and about 2 µm in diameter (Fig.6D).

The S. chaetica 1 on the lateral side of the club arises from a wide sachet and appeared increased in diameter in the half length reached to about 7 µm. The two branches of the sensilla are not equal in length. The sensilla ranged in length from about 31.5 to 35 µm and about 3.5 µm in diameter (Fig.7A).While the S. chaetica 1 on the surface of club gathered into dense collections and mostly destroyed. Some of the collected sensilla were mostly fused with loss of parts of each sensillum (Fig.7C).In other collection, the sensilla were markedly

The sensilla were few in number, markedly shrunken. The part near to the socket was

measures from about 28.8 to 30 µm and the diameter about 7 µm (Fig.6B).

(B): Swollen sensilla chaetica 2 (Ch2) on the surface of the club, (C): Blunt swollen tip of sensilla chaetica 2 (Ch2), (D): Irregularity of sensilla chaetica1(Ch1) on the surface of the

club. [Scale bars indicate 20 µm (A), 100 µm (B) and 10 µm (C, D), respectively]

suddenly interrupted into a blunt swollen tip (Fig. 5C).

to10 µm and the diameter about 2 µm (Fig.4C).

**3.6.2 The effects of the dose rate 20 Gray** 

and the diameter about 9.5 µm (Fig.6A).

**3.6.2.1.2 Sensilla coeloconica 2**

**3.6.2.1.3 Sensilla coeloconica 3**

**3.6.2.2 Sensilla chaetica**

**3.6.2.2.1 Sensilla chaetica** 1

**3.6.2.2.2 Sensilla chaetica 2** 

shrunken and curved into different directions.

swollen, while the apical part disappeared (Fig.7B).

**3.6.1.2.2 Sensilla chaetica 2** 

**3.6.1.3 Sensilla basiconica 1** 

**3.6.2.1 Sensilla coeloconica 3.6.2.1.1 Sensilla coeloconica 1**

> The sensilla thinned out, some of them lost the bifurcation at the apical part others fade into a blunt tip (Fig.6C). The length of sensilla ranged from about 18.5 to 27 µm in length and about 6 µm in diameter.

Ultrastructure Alterations in the Red Palm Weevil Antennal Sensilla Induced By Gamma Irradiation 241

Coeloconic sensilla often consist of a peg whose wall is composed of numerous parallelruning fingers (Keil, 1997). Also, Ameismeier (1985) illustrated that some of the fingerlike projections remained interstitial while some ones combined with each other and remained longitudinal grooves on the surface of the sensilla wall. Hunger and Steinbrecht (1998) observed the coeloconic sensella to be double walled, multiporous, rich in neurons and excessive contact interfaces. Other authors even considered that this type of sensilla may participate in receptivity to heat and humidity (Cuperus, 1983). Olson & Andow (1993) suggested an olfactory function of this sensillar type in *Trichogramma nubilale*, but as revealed in several insect species (Altner *et al*., 1983), this sensillar type may be involved in thermo- or hygroreception. Coeloconica sensilla are found in many Hymenoptera belonging to several families and have been described by different terminologies, such as, small sub terminal sensilla, (Weselow, 1972), multiporous grooved sensilla (Barlin *et al.*, 1981), bulb sensilla (Cave & Gaylor, 1987) and smooth basiconica sensilla (Norton & Vinson, 1974).

Sensilla trichodea 1 has been described in different insects as having putative mechanoreceptive functions, such as in the perception of mechanosensory stimuli (Onagbola & Fadamiro, 2008). Keil (1999) cited that trichoid sensilla may be olfactory, but sensilla found on the pedicel are usually mainly mechanoreceptive. Schneider (1964) suggests that trichoid sensilla may be dye-permeable and so may posses chemoreceptivity. The great occurrence of the sensilla trichodea on the antennae of male *O. elegans* relative to the females may indicate a probable role in mate location, possibly for the detection of

Sensilla trichodea1 was found on the antennae of *Bembidion* species. These bristles are innervated by a single sensory neuron, ending with the typical tubular body, attached to the

Sensilla similar to sensilla trichodea 2 have been described on several species of curculionid beetles (Alm & Hall 1986 and Isidoro & Solinas, 1992). In electrophysiological experiments with *H. abietis*, Mustaparta (1975) found that this sensillar type was electrophysiologically responsive to odours. Merivee *et al.,* (1999) suggested that they probably function as sex pheromone receptors. In the ground beetle, *Platynus dorsalis*, it might indicate that these

Sensilla similar in external morphology to the sensilla trichodea 3 on *R*. *Ferrugineus* are found on other alticinid species (Ritcey & McIver, 1990). The short sensilla trichodea, recorded from *Synempora* by Davis & Nielsen (1980) are in fact microtrichia, which are very frequently found on flagellomeres. They superficially resemble multiporous small sensilla basiconica which so far have been described only from Agathiphagidae among Lepidoptera

The fourth type of trichodea sensilla are found only on the club of *R*. *ferrugineus* in few number are similar to type V sensilla found on the club of *R. palmarum* ,which characteristics of olfactory trichodea sensilla (Said *et al.,* 2003).Such sensilla were found to house neurons tuned to the pheromone component in *Ips typographus* L. and *Hylobius. abietis*

Shields & Hildebrand (2001) showed that every type -trichoid sensilla -of the female sphinx moth *M.sexta* was innervated by two olfactory receptor cells and could respond to aromatic

base of the hair shaft. This indicates a mechanosensory function (Zacharuk, 1985).

sensilla probably respond to aggregation pheromone (Merivee *et al.,* 2001).

females sex pheromones (Onagbola, *et al*., 2008).

(Faucheux, 1990).

(Mustaparta,1973,1975).

Fig. 7. SEM photomicrographs of irradiated adult antenna of *Rhynchophorus Ferrugineus* with 20 Gy of gamma rays. (A): Abnormal sensilla chaetica1 (Ch1) on the lateral side of club, (B): Shrunken and swollen sensilla chaetica 2 (Ch2) on the surface of club, (C): Sensilla chaetica 1 (Ch1) on the surface of club. [Scale bars indicate 20 µm (A, C) and 50 µm (B), respectively]
