Types Of Sensilla Chaetica Research Articles

L'equipement sensoriel de l'antenne d'un coleoptere troglobie, Aphaenops cryticola linder (Coleoptera : Trechinae)

The types, number and the spatial arrangement of the sensilla on the antennae of the cave beetle, Aphaenops crypticola, have been determined by scanning electron microscope. The antenna is composed of 11 segments. There are 3 types of sensilla chaetica and s. trichodea, s. basiconica, s. ampullacea, s. campaniformia, tuberculated-peg, and proprioreceptors; a special type of chemoreceptor is described and named s. basiconica inflata. The antenna has about 1800 sensilla; their number increases from the scape to the distal segment. On the flagellar segments the long s. chaetica type 1 are located on a sub-distal ring, except on the 11th segment where there are 2 rings; the short s. chaetica type 3 are distal; the chemoreceptors appear on the 3rd, 4th and 8th segments. The peg morphology of the sensillum ampullaceum is described.

External morphology of antennae and their sense organs in the roach Gromphadorhina brunneri (Blattoidea: Dictyoptera).

The antennae and their sense organs in nymphs and adult roaches of Gromphadorhina brunneri, were investigated and described. The number of segments and sensillae of the nymphal antennae depend on the developmental stage. Sexual dimorphism is pronounced. Males have longer antennae than females as well as an abundance of especially long sensory hairs (long wavy hairs), which are probably responsible for the perception of female sex pheromones. They also have more thin-walled sensory hairs, for instance, sensilla trichodea. On a morphological basis the sensillae of Gromphadorhina brunneri, were named and classified. Long wavy hairs and large sensory hairs appear to be present also in a related species, G. portentosa, but are lacking in others. Their distribution on the antennae varies greatly from that in G. portentosa but their structure varies only slightly. These two types of sense organs are considered to be specialized forms of sensilla chaetica. They are contact chemoreceptors, as are two other types of sensilla chaetica. Furthermore, thin-walled chemoreceptors are present, such as sensilla trichodea, sensilla basiconica, sensilla coeloconica and a typical mechanoreceptor, the sensillum campaniformium.

Morphology and histology of the antenna of the male eastern spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae)

The number and distribution and the morphology of the various receptors on the male antenna of the spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae), are described, using histological techniques and scanning electron microscopy. Receptors described include Böhm bristles, four types of sensilla trichodea, sensilla chaetica, sensilla coeloconica, and sensilla styloconica. Except for the sensilla chaetica, generally more receptors are found on the male than on the female antenna.

Antennal Morphology of the New Guinea Sugarcane Weevil, Rhabdoscelus obscurus1,2

The antennae of Rhabdoscelus obscurus (Boisduval) (Coleoptcra: Curculionidae) were studied with light and scanning electron microscopes. The antenna is geniculate and consists of 8 segments. Scape and pedicel have Bohm bristles and segments 3-8 of the antenna, except the apex of the club, have sensilla chaetica type I and sensilla campaniformia. The apex of the club has sensory pockets plus 8 types of sensilla: sensilla trichodea, basiconica, campaniformia, chaetica (2 types), and coeloconica (3 types). Sensilla basiconica and coeloconica type II were also found inside each sensory pocket. Sexual dimorphism in size and type of sensilla is not marked; however, females have slightly more of each type of receptor than males.

Fine Structure of the Sensilla Chaetica on the Antennae of Aedes aegypti (Diptera: Culicidae)1

The fine structure of the 3 types of sensilla chaetica, including the fibrillae of the male, on the antennae of male and female Aedes aegypti (L.) has been determined and compared. Although differences in size and location occur, all types have similar structure. The sensilla chaetica are innervated by one eccentrically placed neuron and have a structure generally resembling that reported from other hair mechanoreceptors, except for the occurrence of a non-membrane-bounded, spherical, lucid area in the dense material filling the extracellular space of the tormogen cell. The possible significance of this lucid area, a new observation for hair mechanoreceptors, is discussed.

Antennal sense organs of female Culex tarsalis (Diptera: Culicidae).

The types, numbers, and distribution of antennal sense organs of female Culex tarsalis Coquillett are reported. There are about 1025 sense organs on the flagellum which are classified as 2 types of sensilla chaetica, sensilla basiconica, 3 types of sensilla trichodea, and sensilla campaniformia. Except for the first few basal segments, the pointed-tipped sensilla trichodea are fairly evenly distributed on the flagellum. The number of type I blunttipped sensilla trichodea decrease distally while the sensilla basiconica increases. Type II blunt-tipped sensilla trichodea occur 1 per segment. Electron micrographs show a light tip on the sensilla basiconica indicating a decrease in thickness of the cuticle. A central canal in the basiconica is visible with the light microscope. Using the crystal violet staining technique for detecting permeable sense organs, it was found that the sensilla basiconica took up the stain as well as the type I blunt-tipped sensilla trichodea.

THE SENSORY ORGANS OF THE MOSQUITO ANTENNA

Using Aedes aegypti (L.) as the chief example, an account of the adult mosquito antenna, male and female, is given, and the different types of setae found thereon are described. Two of these, called types A1 and A3, are, respectively, sensilla trichoidea and sensilla basiconica; they are located chiefly at the distal end of the antenna and diminish in numbers towards its base. Type A2 setae are also sensilla trichoidea, but are smaller than type A1; they are most numerous at the base of the antenna and diminish in numbers towards the distal end. The total number of these three types is over 600 on each antenna in A. aegypti. At the tip of the antenna there are two sensilla campaniformia. Another type of seta, called A4, consisting of sensilla coeloconica, has been found so far only on the antenna of Anopheles spp. There are also two types of sensilla chaetica, making altogether seven different kinds of setae found on the mosquito antenna. Experiments with A. aegypti indicate that type A1 setae may mediate attractive odors such as that of the human hand, while type A2 setae may mediate repellent odors such as that of "612". The possible functions of the other setae are briefly considered.