**3.5.3.3 Sensilla trichodea 3**

232 Gamma Radiation

Sensilla coeloconica 1 (S.C1) were located in a large and low lumen on both sides of the scape (Fig.2A). S.C1 was distinguished by their finger-like appearance, which characterizes it from the other sensilla. On high magnification, the sensilla appears to be formed of multiple straight tubules directed towards the antennal shaft giving a pyramidal appearance, opening at the apex with many ridges on the surface wall of the sensilla.. Each one arises from a narrow socket; the base of sensilla may be attached to the socket in some parts. The sensilla measures about 16.8 µm in length and about 11.3 µm in diameter (Fig.2A). Two subtypes of these sensilla were distinguished, on the pedicel**,** the first, Sensilla coeloconica 1 was scattered in a little numbers and have been described previously, the second, Sensilla coeloconica 2 which emerges from a well-defined socket. The fingers are long and tapering apically, some arise from sockets with tilting towards the antennal shaft, and have triangular shape. They have veins ornamented vertically on the surface of the sensilla wall. These sensilla ranged from about 30.8 to 41.3 µm in length, and about 15.8 µm in diameter (Fig.2B). Few numbers of S.C1 are distributed on the 3rd, 4th and 5 th segments of funnels on the flagellum while, S.C 3 are found on the 3rd segment of the funnel. The fingerlike processes of S. coeloconica 3 are long and fused into a blunt tip. Number of them is tapering apically, extends with the same diameter and has an elongated triangular appearance. They grow out from wide sockets and extend in a straight line on the antennal shaft (Fig.3A). These sensilla measured about 18 µm in length, and about 5 µm in diameter.

Sensilla basiconica 1 are found on the ventral side between the scape and the pedicle in one row. It is a hair with a simple bulky base and a wide socket, and this hair ending fans out into two curved parts in line with the curve of the whole sensilla. These sensilla ranged from about 12.5 to 18.8 µm in length, and ranged about 5.0 to 6.5 µm in diameter (Fig.2C). Sensilla basiconica 2 are spread in a very few number on the surface of the club. They are blunt tipped, relatively stout pegged. They are often straight and sometimes slightly curved

They show no special arrangement except that they are more frequent on the apical and

It is formed of straight hair, tapering to a fine end, growing out from a socket in the cuticle. The surface of the sensilla is smooth. It is measured about 240 µm in length and about 12.5

It is a straight hair and most of them are blunt-tipped while few of them are bifurcate at the terminal end (Fig.2D). The hair bases inserted tightly into a large cuticular socket and the surface of the sensilla is similar to trichodea 1. They have a mean length about 105 µm and

**3.5 The different types of sensilla** 

**3.5.1 Sensilla coeloconica** 

**3.5.2 Sensilla basiconica** 

**3.5.3 Sensilla trichodea** 

**3.5.3.1 Sensilla trichodea 1**

**3.5.3.2 Sensilla trichodea 2**

mean diameter about 12.5 µm.

towards the antennal shaft (Fig.3F).

µm in diameter at its base (Fig.2D).

basal areas of the segmented funnily on the flagellum.

The sensilla of this type are straight, and tapering to a fine point. In some sections, a socket of cuticle is found close to the base of the sensilla. The length measures about 70 µm and the diameter about 12.5 µm (Fig. 2D). Sensilla trichodea 1, 2, 3 observed on the lateral side of the club without any arrangement and have been described previously (Fig.2D).

Ultrastructure Alterations in the Red Palm Weevil Antennal Sensilla Induced By Gamma Irradiation 235

These S. trichodea are present only in a few number on the surface of the club and are smooth –walled. Most of them have about the same length of S. chaetica 1 on the surface of club. The apical part of these sensilla is remarkable split into two branches. These branches

These sensilla are thick and bifurcate at the half of length, and appear very sharply pointed at their apical margin of equal branches on the flagellum. They are smooth walled and distributed on all the surface of funnel .Some of them is extended in a straight way while the others are gently curved. The length ranged from 32.5 to 50.0 µm and the diameter about 12.5 µm (Fig.2D). These sensilla also, are most abundant on the surface of club; some of them are extended straight while the others gently curved (Fig.3F). S. chaetica 1 resemble that found on funicle (thick, bifurcate from about the middle part of sensilla, and appeared very sharply pointed at their apical margin of equal branches).Also, they could be observed on the lateral sides of the club, the two branches of these sensilla arisen from about middle or third total length and each branch are also divided into two parts (Fig.3D). The S. chaetica 1 on the lateral sides of the club not curved on the antennal shaft and measure about 33.5 µm

They are long hair-like structures arranged in a line on the surface of the club. They are similar in shape to S. trichodea but much longer in length (approximately three or four times), and found fewer in number compared with other sensilla types. Some of their long axis forms a right angle with antennal shaft while others form an angle of around 60 ºC with the antennal surface to protrude well above all the other sensilla. Distally, it tapers

Abundant cuticular pores vary in their size and location and can be found in-between the sensilla on the whole surface of the lateral side of club and the first segment of the funnel (Figs.2D, 3D). Few numbers of medium-sized pores are noticed on the cuticular depression

The following sensilla showed certain alterations while the remaining ones did not show

Changes in general appearance, enlarged in size and irregularity in shape were noticed. The base of sensilla became less dense especially in central part. The finger like processes at the

are different in length and diameter and they are straight or slightly curved (Fig. 3F).

**3.5.3.4 Sensilla trichodea 4**

**3.5.4 Sensilla chaetica 3.5.4.1 Sensilla chaetica 1**

in length and about 4 µm in diameter.

at the 2nd segment of the funnel (Fig.2D).

**3.6.1 The effects of the dose rate 15 Gray** 

uniformly into simple extremities with pointed tips (Fig. 3E).

**3.6 The effects of gamma irradiation on the antennal sensilla** 

**3.5.4.2 Sensilla chaetica 2** 

**3.5.5 Cuticular pores** 

specific changes.

**3.6.1.1 Sensilla coeloconica 3.6.1.1.1 Sensilla coeloconica 1**

Fig. 3. SEM photomicrographs of non-irradiated adult antenna of *Rhynchophorus Ferrugineus.*  (A): Sensilla coeloconica 3 (C3) on the funicle, (B): Sensilla trichodea 1,2,3 (T1,T2,T3) and Cuticular pores as arrowheads on the lateral side of the club, (C): Bifurcat trichodea 2 (T2) on the lateral side of the club, (D): Sensilla chaetica1 (Ch1) on the lateral side of the club, (E): Sensilla chaetica 2 (Ch2) on the surface of the club, (F): Sensilla Basiconica 2 (B2), Sensilla Trichodea 4 (T4) and Sensilla chaetica1(Ch1) on the surface of the club. [Scale bars indicate 20 µm (A, C, D), 100 µm (B), 50 µm (E) and 10 µm (F), respectively]
