Herbivore insects are suitable model organisms for studying how plant odor information is encoded in olfactory receptor neurons (RNs). By the use of gas chromatography linked to electrophysiological recordings from single RNs, screening for sensitivity to naturally produced plant odorants is possible in order to determine the molecular receptive ranges of the neurons. Using this method, we have...

Electron micrographs of sections of the labellar chemosensilla of the blowfly, Phormia regina, showed that treatment with sodium deoxycholate (DOC; 7.2 mM for 2 min) destroyed the distal processes of the receptors from up to 10 microns from the tip of the sensillum, but these processes regenerated almost completely within 0.5 h. However, when DOC treatment was preceded by colchicine treatment (...

With the swede midge (Contarinia nasturtii) as our main model species, we study two types of olfactory cues that are of importance for gall midges: 1) the pheromones emitted by the female to attract the male; 2) and the host plant volatiles that the females use when finding a host for oviposition. We found that both the blend of compounds and the enantioisomeric form are important for male attr...

The molecular mechanisms mediating chemosensory discrimination in insects are unknown. Using the enhancer trapping approach, we identified a new Drosophila mutant, lush, with odorant-specific defects in olfactory behavior. lush mutant flies are abnormally attracted to high concentrations of ethanol, propanol, and butanol but have normal chemosensory responses to other odorants. We show that wil...

Water is a critical resource for any terrestrial animal, especially for a soft-bodied insect such as larvae of the tobacco hornworm, Manduca sexta L. (Lepidoptera: Sphingidae). Strategies for coping with a dry environment might include seeking out regions of high relative humidity that reduce desiccative stress, or to find and imbibe liquid water. Desiccated larvae placed in a linear arena with...

A central question in insect chemoreception is whether signaling occurs via G-proteins. Two families of seven-transmembrane-domain chemoreceptors, the odor (Or) and gustatory receptor (Gr) families, have been identified in Drosophila (Clyne et al., 1999, 2000; Vosshall et al., 1999). Ors mediate odor responses, whereas two Grs, Gr21a and Gr63a, mediate CO2 response (Hallem et al., 2004; Jones e...

Two sympatric species Helicoverpa armigera and Helicoverpa assulta use (Z)-11-hexadecenal and (Z)-9-hexadecenal as sex pheromone components in reverse ratio. They also share several other pheromone gland components (PGCs). We present a comparative study on the olfactory coding mechanism and behavioral effects of these additional PGCs in pheromone communication of the two species using single se...

The sex pheromone of the scarab beetle, Phyllopertha diversa, is emitted by females and specifically detected by olfactory receptor neurons in the male and female antennae. Single sensillum recordings showed that, in contrast to the less sensitive pheromone sensilla in females, olfactory receptor neurons in the male antennae had a low threshold (1 ng), which rivals those of moths. The male and ...

The common bed bug Cimex lectularius is a temporary ectoparasite on humans and currently resurgent in many developed countries. The ability of bed bugs to detect human odorants in the environment is critical for their host-seeking behavior. This study deciphered the chemical basis of host detection by investigating the neuronal response of olfactory sensilla to 104 human odorants using single s...

Odorant binding proteins (OBPs) play an important role in insect olfaction, facilitating transportation of odorant molecules in the sensillum lymph. While most of the researches are concentrated on Lepidopteran and Dipteran species, our knowledge about Orthopteran species is still very limited. In this study, we have investigated OBPs of the desert locust Schistocerca gregaria, a representative...