Ultrastructure of Insect Sensilla

2012 ◽  
Keyword(s):  
Insect Sensilla

Cellular organization and fine structure of type II microtrich sensilla in gammaridean amphipods (Crustacea)

1999 ◽  
Vol 77 (1) ◽  
pp. 88-107 ◽  
Author(s):  
V J Steele ◽  
D H Steele
Keyword(s):  
Sensory Neurons ◽  
Sensory Cell ◽  
Cell Process ◽  
Outer Cell ◽  
Type Ii ◽  
Cellular Organization ◽  
Insect Sensilla ◽  
Transmission Electron ◽  
Cell Processes ◽  
Tormogen Cell

The cellular organization of type II microtrich sensilla was studied in male Anonyx lilljeborgi Boeck, 1871 (Lysianassoidea) by light and transmission electron microscopy. The sensillum consists of two bipolar sensory neurons and three concentric sheath cells. The sensory cell bodies are subepidermal. In each sensillum both dendrites are enclosed by the thecogen cell process. The inner dendritic segments are filled with mitochondria and lucent vesicles and expand in the epidermis into a spindle-shaped swelling. One of the neurons gives rise to two cilia and the second to a single cilium. These three outer dendritic segments lie in the receptorlymph cavity. The dendritic sheath, secreted by the thecogen cell process, completely ensheaths the outer dendritic segments. The trichogen (middle) cell and the tormogen (outer) cell incompletely enclose the thecogen cell, but their processes form autojunctions around the dendritic sheath in the apical epidermis. In premolt, the trichogen cell processes project into the exuvial space. The cytoplasm of the tormogen cell and the bordering epidermal cells contains coarse osmiophilic inclusions. All the cells of the sensillum are joined by desmosomes. The sensilla structurally resemble chemosensory (gustatory) insect sensilla.

Morphological Correlates of Differences in Pheromone Sensitivity in Insect Sensilla

Science ◽  
1983 ◽  
Vol 220 (4604) ◽  
pp. 1408-1410 ◽  
Author(s):  
R. J. O'CONNELL ◽  
A. J. GRANT ◽  
M. S. MAYER ◽  
R. W. MANKIN
Keyword(s):  
Insect Sensilla

The fine structure of uniporous and nonporous pegs on the distal antennal segment of the diving beetle Graphoderus occidentalis Horn (Coleoptera: Dytiscidae)

1991 ◽  
Vol 69 (2) ◽  
pp. 334-352 ◽  
Author(s):  
J. C. Jensen ◽  
R. Y. Zacharuk
Keyword(s):  
Fine Structure ◽  
Antennal Segment ◽  
Terminal Segment ◽  
Sheath Cell ◽  
Terrestrial Habitat ◽  
Insect Sensilla ◽  
Virus Like Particles ◽  
Accessory Cells ◽  
Different Types ◽  
Diving Beetle

The terminal segment of the antenna of the predaceous diving beetle Graphoderus occidentalis Horn bears approximately 50 sensilla of nine different types. There are six types of uniporous chemosensilla, one type of nonporous mechanosensitive peg, and two types of multiporous pegs. Two types of uniporous pegs, which occur only at the antennal tip, have features of both contact chemosensilla and thermo- and hygro-sensilla. Three other types that occur only on the terminal segment below the apex also exhibit some features of chemosensilla and thermo- and hygro-sensilla. The sensilla are innervated by one to four neurons and most are ensheathed by two accessory cells. Four types of sensilla exhibit elaborate sheath cell configurations and secretions associated with their sinus that may reflect an adaptation to an aquatic or a dual aquatic–terrestrial habitat. All are atypical of generalized insect sensilla in having portions of the proximal dendrites and axons as well as the entire neuronal perikarya unsheathed and exposed to the hemocoel. The neuronal perikarya of two sensillar types contain virus-like particles.

Sign in / Sign up

Export Citation Format

Share Document