ABSTRACT

Most insects have contact chemoreceptors on various surfaces of their body. The relationship between contact chemoreceptors and landing of female moths in the field to find out a suitable place for egg laying is very important to discover a suitable places for the immature and adults to complete their development. This sense of taste can be involved in a number of behaviours, including avoidance, detection and the selection of food and selection of egg-laying sites. Their contact chemoreceptors have only one terminal porous (basiconic sensilla) and five sensory neurons at their base, with one responding to mechanical contact and the others to different classes of attractant or repellent chemicals. Responses to aqueous solutions of salts (NaCl), sugars (glucose), acids (citric acid), oviposition aggregation pheromones (veratrole and acetophenone), alkaloids (quinine and tomatine), and phenolic compounds (salicin) were seen. Higher order processing occurs in local and ascending interneurones of the terminal abdominal ganglion.

Key words: Taste sensilla, locust ovipositor, chemical stimulants, aggregation pheromones, ascending interneurones.