The accessory organ, a scolopidial sensory organ, in the cave cricket Troglophilus neglectus (Orthoptera: Ensifera: Rhaphidophoridae). (2nd February 2015)

• Record Type: Journal Article
• Authors: Strauß, Johannes; Stritih, Nataša
• Is Part Of: Acta zoologica. Volume 97:Number 2(2016:Apr.)
• Page Start: 187
• Page End: 195
• Publication Date: 2015-02-02
• Subjects: insect -- neuroanatomy -- scolopidial organ -- mechanoreception -- innervation -- cave cricket -- neuronal tracing; Zoology -- Periodicals; 590
• DOI: 10.1111/azo.12116
• Languages: English
• ISSNs: 0001-7272

Abstract

Abstract: Mechanoreceptor organs occur in great diversity in insect legs. This study investigates sensory organs in the leg of atympanate cave crickets ( Troglophilus neglectus KRAUSS, 1879) by neuronal tracing. Previously, the subgenual and the intermediate organs were recognised in the subgenual organ complex, lacking the tympanal membranes present for example in the tibial hearing organs of Gryllidae and Tettigoniidae. We document the presence of the accessory organ in T. neglectus . This scolopidial organ is located in the posterior tibia close to the subgenual organ and can be identified by position, innervation and orientation of the dendrites of sensory neurons. The main motor nerve in the leg innervates a part of the subgenual organ and the accessory organ. The dendrites of sensory neurons in the accessory organ are characteristically bent in proximo‐dorsal direction, while the subgenual organ dendrites run distally along the longitudinal axis of the leg. The accessory organ contains 6–10 scolopidial sensilla, and no differences in neuroanatomy occur between the three thoracic leg pairs. Hence, the subgenual organ complex in cave crickets is more complex than previously known. The wider taxonomic distribution of the accessory scolopidial organ among orthopteroid insects is inconsistent, indicating its repeated losses or convergent evolution.