Antennae morphology

The morphological dependence of the antenna effect was quantitatively studied by the comparison of the three focal isomers of benzene-cored 4th-genera-tion dendrimers [7]. The energy of the photon absorbed by the dendron subunits must be dissipated either through radiative (luminescence) or nonradia-... 

We reported the preparation of sophisticated bipolar three-dye photonic antenna materials for light harvesting and transport [22]. The principle is illustrated in Figure 1.12. Zeolite L microcrystals of cylinder morphology are used as host for organizing several thousand dyes as monomers into well-defined zones. 

P americana is one of just a few species of insects in which both peripheral and central olfactory processing have been studied. In contrast to many short-lived lepidopterans, in which the male antenna is highly specialized for sex pheromone reception, the antennae of male cockroaches contain numerous food-responsive sensilla. In addition to olfactory sensilla, the antennae also house mechano-, hygro-and thermoreceptors, as well as contact chemoreceptors (Schaller, 1978 review Boeckh et al., 1984). Extensive ultrastructural and electrophysiological evidence has demonstrated that morphologically defined sensillum types house receptor cells of specific functional types (Sass, 1976, 1978, 1983 Schaller, 1978 Selzer, 1981, 1984 review Boeckh and Ernst, 1987). Boeckh and Ernst (1987) defined 25 types of cell according to their odor spectra, but of the 65 500 chemo- and mechanosensory sensilla on the antenna of adult male P. americana, an estimated 37 000 house cells that respond to periplanone-A and periplanone-B. 

Sexual dimorphism of antenna sensillum types does not become morphologically apparent before the adult stage. Antennal segments increase in length approximately three-fold during postembryonic development in both males and females (Schafer and Sanchez, 1976). In the female, the sensillar population increases 7.5-fold, whereas adult males have 12 times more sensilla than first instars the difference results from a significant proliferation of olfactory sensilla in males. 

Ramaswamy, S. B. and Gupta, A. P. (1981). Sensilla of the antennae and the labial and maxillary palps of Blattella germanica (L.) (Dictyoptera Blattellidae) their classification and distribution. Journal of Morphology 168 269-279. 

Insect antennae vary tremendously in size and shape, but two common forms are filiform (a single cylinder) and pectinate (feathery arrays of many cylinders). Most of the published morphological information on insect antennae concentrates on sensory hairs (e.g. Zacharuk, 1985 Steinbrecht, 1987, 1999 Zacharuk and Shields, 1991). Descriptions of sensory hair morphology are necessary for biomechanical analyses and interpretation, but it is equally important to have... 

Antennal morphologies that slow the air flow in the vicinity of the sensory hairs, such as pectinate antennae that typically pass only about 10 percent of the approaching air, will distort the flow in a particular way - they will cause spreading (divergence) of the air stream as it approaches an antenna. This distortion of the air means that a small patch of odorant molecules will strike a much larger number of sensory hairs than would be predicted on the basis of the undistorted patch size (Loudon and Davis, unpublished). 

Schneider R. W. S., Price B. A. and Moore P. A. (1998b) Antennal morphology as a physical filter of olfaction temporal tuning of the antennae of the honeybee, Apis mellifera. J. Insect Physiol. 44, 677-684. 

Bowen M. F. (1995) Sensilla basiconica (grooved pegs) on the antennae of female mosquitoes electrophysiology and morphology. Entomol. Exp. Appl. 77, 233-238. 

The diverse morphology of the olfactory organ among insect species provides a basis upon which classification has been based. Basically, the olfactory organ in the adult insect comprises two components on the head the antenna and the maxillary palp (Fig. la). Numerous sensilla cover the surface of the antennae and prevent direct contact of ORNs with the external environment. Each sensillum is filled with a potassium- and protein-rich fluid called sensillum lymph and houses one to four ORN dendrites. The small pits on the cuticle surfaces of sensilla allow contact of the ORN dendrite with volatile odorants that dissolve in the lymph. In Drosophila, the third segment of the antenna and of the maxillary palp possess approximately 1,200 and 120 ORNs, respectively. 

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