|Chinta, Srinivas - MISSISSIPPI STATE UNIV.|
|Baker, Gerald - MISSISSIPPI STATE UNIV.|
Submitted to: Journal of Insect Morphology and Embryology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 19, 1996
Publication Date: N/A
Interpretive Summary: The tarnished plant bug (TPB) is a polyphagous insect with over 400 known hosts, of which more than 100 are economically important plants. Previous studies revealed that female TPBs release a sex attractant for males which is likely detected by sensory nerve cells housed within hair-like structures called sensilla on male antennae. We examined these antennal sensilla in sexually-immature and adult TPB to reveal potential functions of sensory cells associated with each type and to determine sexual differences. Six types of sensilla occur in TPB adults; only five types are present in immature forms. Three types of sensilla have walls with numerous pores characteristic of sensilla involved in smell. Two sensillar types have only a pore in their tip and probably function in taste. One type of sensillum has multiple pores in its wall as well as a pore in the tip. Two types of smell sensilla, including the adult-specific sensilla type, and two types of taste sensilla are more abundance in males than in females. Determination of the potential sensory roles of sensilla in TPB provides bases for electrophysiological studies of nerve cells associated with them to discover behavioral chemicals for use in survey and control of this pestiferous insect.
Technical Abstract: Sensilla on antennae of adult and last instar nymphs of the tarnished plant bug, Lygus lineolaris, were examined with light and scanning and transmission electron microscopy. Six different types were identified in adult females and males and 5 types in last instar nymphs: types 1 & 4 are sensilla trichodea, 2 & 3 are sensilla chaetica and 5 & 6 are sensilla basiconica. Types 1 & 2 were located at distal regions of terminal and proximal 3 segments in adults and nymphs. Type 3 was present on all segments, more numerous on scape and pedicel and less abundant on distal 3rd and 4th segments in adult and nymphal stages. Types 4 & 6 were absent on scape and present on distal 3 antennal segments in adults but these types were present only on the distal most antennal segment in nymphs. Type 5 sensilla were present only on 2nd antennal segments in adults and were absent in nymphs. Sexual dimorphism was observed in total numbers. There were significantly more types 3,4,5 and 6 sensilla in adult males. Types 1,4 & 5 were multiporous with thin cuticle, branched dendrites and pore tubules suggesting their role in olfaction. Type 6 sensillum had an apical pore and pores on their cuticular walls, innervated with 5 unbranched nerve cells.