Morphological and neurophysiological characterization of olfactory sensory organs in the house cricket

Abstract

House crickets, Acheta domesticus (L.), (Orthoptera Gryllidae) are known serious pests of wheat, grain, oil seed, and millet. These insects have paired antennae that are endowed with many sensory organs (sensilla) which allow them to acquire information pertaining to smell, taste, and mechanical stimuli about their environment. Each long antenna has many segments (~200) called annuli. Each annulus bears as many as five types of sensilla. There are three types of olfactory sensilla that are used to detect odor molecules. Two types (type-I and type II) resemble short hair-like structures or pegs called basiconic sensilla. Another type resembles a short peg within a pit (coeloconic sensilla). There is one type of mechanosensory sensillum (trichoid sensillum) that resembles a long hair, responsible for detecting mechanical stimulation. One type of gustatory sensillum bears a single terminal pore and is responsible for detecting taste molecules. Results thus far, using electroantennograms, reveal that house crickets respond to complex odorant mixtures in fruits, such as cherry, peach, and banana. Gas chromatography-electroantennographic detection with coupled mass spectrometry techniques (GC-EAD/MS) will be used to determine single component volatiles responsible for these responses.