Influence of DDT and Lindane on Chordotonal Organs in the Cockroach

Abstract

THERE has been much interest recently in stretch and strain receptors in Arthropods. Wiersma et al. ¹ studied the responses of paired ‘muscle receptor organs’ in decapod Crustacea; these consist of muscle fibres with intercalated tendinous regions and are located dorsally in the abdomen and thorax. They found a slowly adapting unit response (tonic) and a comparatively fast adapting unit (phasic). According to Finlayson and Lowenstein², proprio-ceptors in the dorsal longitudinal muscles of the abdomen of some saturniid moths consist of modified muscle fibres, and show tonic but not phasic discharges. In Limulus, Pringle³ recorded tonic discharges from proprioceptive nerve endings in the cuticle of the femoro-tibial joint, and obtained phasic responses from more internally situated chordotonal-like organs. Much histological information is available about internal stretch receptors in insects⁴, but apart from Hughes's⁵ work on abdominal chordotonal organs, their physiological properties are unknown.