Contact Chemoreceptors Research Articles

The Location of the Contact Chemoreceptors of the Cherry Fruit Fly, Rhagoletis Cingulata and the Flesh Fly, Sarcophaga Bullata

In the Diptera, tarsal contact chemoreceptors have been found in the following species: Phormia regina, P. terraenovae, Phaenicia sericata, Calliphora vomitoria, C. vicina, Cynomyopsis cadaverina, Callitroga macellaria, Stomoxys calcitrans, Musca domestica, Drosophila melanogaster, Tubifera sp., Tabanus sulcifrons (references to original studties in Frings and Frings, 1949) and Aedes aegypti (Frings and Hamrum, 1950). These represent only six families of this large and important order of insects. Tarsal chemoreceptors have been reported as being absent in Rhagoletis pomonella2 (Trypetidae) by Middlekauf (1941), the only species of fly tested so far in which these receptors have not been found. Labellar contact chemoreceptors have long been assumed to exist in the Diptera. They have been proved to exist, however, only in Phormia regina, Calliphora vomitoria, C. vicina, Phaenicia sericatta, Musca domestica, Tubifera sp., Tabanus sulcifrons (Frings and Frings, 1949) and Aedes aegypti (Frings and Hamrum, 1950). No exceptions have been reported for any flies tested. The present paper reports studies on two species of Diptera-the cherry fruit fly, Rhagoletis cingulata (Trypetidae) and the flesh fly, Sarcophaga bullata (Sarcophagidae). Studies on the first species test the possibility that this may represent an exceptimn to the rule in Diptera. Studies on the second add data on the location of contact chemoreceptors in a species from a family whose members have not previously been tested.

Contact chemoreceptors of blowfly tarsi.

THE contact chemoreceptors of blowfly tarsi have been the subject of much experimental work since the existence of a tarsal taste sense in the Calliphoridae was discovered by Minnich1; the literature has been reviewed elsewhere2,3. The receptors concerned have not been positively identified and no details of the structure of the receptor surface have been reported.

Olfactory stimulation of blowflies by homologous alcohols.

The response of the blowfly Phormia regina to stimulation by alcohols in the vapor phase has been investigated by means of an olfactometer which permitted quantitative control of stimulus concentration. The median rejection threshold was selected as a criterion of response. As was true in the case of contact chemoreception, the distribution of thresholds in the fly population is normal with respect to the logarithm of concentration. In terms of molar concentration the alcohols are rejected at logarithmically decreasing concentration as chain length is increased. Beyond decanol there is no further stimulation. When thresholds are expressed as pressures and plotted against saturated vapor pressures on logarithmic coordinates, the data fit a line the slope of which is not significantly different from 1; i.e., the thresholds vary directly with vapor pressure. Individual threshold values, however, deviate significantly from this line. and the deviation must be ascribed to other factors which have not as yet been identified. When thresholds are expressed as activities, all alcohols are equally stimulating. It appears that the limiting process of olfaction, at least in so far as the normal alcohols are concerned, may involve an equilibrium process. Conformity to this concept is most exact for intermediate members of the series.

Addendum to "The Loci of Contact Chemoreceptors in Insects."

Addendum to "The Loci of Contact Chemoreceptors in Insects."

The Loci of Contact Chemoreceptors in Insects. A Review with New Evidence

The Loci of Contact Chemoreceptors in Insects. A Review with New Evidence

STIMULATION OF TARSAL RECEPTORS OF THE BLOWFLY BY ALIPHATIC ALDEHYDES AND KETONES

Rejection of eight aldehydes, eight ketones, five secondary alcohols, and 3-pentanol has been studied in the blowfly Phormia regina Meigen. The data agree with results previously reported for normal alcohols and several series of glycols in showing a logarithmic increase in stimulating effect with increasing chain length. The order of increasing effectiveness among the different species of compounds thus far investigated is the following: polyglycols, diols, secondary alcohols, iso-alcohols, normal alcohols, ketones, iso-aldehydes, normal aldehydes. Curves relating the logarithms of threshold concentration to the logarithms of chain length for diols, alcohols, aldehydes, and ketones show inflections in the 3 to 6 carbon range. Above and below the region of inflection the curves are nearly rectilinear. The slopes for the upper limbs (smaller molecules) are of the order of -2; for the lower limbs, about -10. Comparisons of the threshold data with numerical values for molecular weights, molecular areas and volumes, oil-water distribution coefficients, activity coefficients, standard free energies, vapor pressures, boiling points, melting points, dipole moments, dielectric constants, and degree of association are discussed briefly, and it is concluded that none of the comparisons serves to bring the data from the several series and from the two portions of each series into a single homogeneous system. A qualitative comparison with water solubilities shows fewer discrepancies. It is suggested that the existence of a combination of aqueous and lipoid phases at the receptor surface would fit best with what is presently known about the relationship between chemical structure and stimulating effect in contact chemoreception. In this hypothesis the smaller and more highly water-soluble compounds are envisaged as gaining access to the receptors partly through the aqueous phase, the larger molecules predominantly through the lipoid phase.

A contribution to the comparative physiology of contact chemoreception.

A contribution to the comparative physiology of contact chemoreception.

The loci and thresholds of contact chemoreceptors in females of the horsefly, Tabanus sulcifrons MACQ

The loci and thresholds of contact chemoreceptors in females of the horsefly, Tabanus sulcifrons MACQ

On the Sensitivity of the Chemoreceptors on the Antenna and Fore-Tarsus of the Honey-Bee, Apis Mellifica L

ABSTRACT The experiments to be described were undertaken as a preliminary study of the reactions of the contact chemoreceptors on the antenna and fore-tarsus of the honey-bee, Apis mellifica L., to various concentrations of sucrose solutions. Experiments were also carried out to estimate the effect of antennal amputation on chemotropic response.