**3.5.4 Sensilla chaetica**

### **3.5.4.1 Sensilla chaetica 1**

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 in length and about 4 µm in diameter.

#### **3.5.4.2 Sensilla chaetica 2**

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