Behavioral Consequences of Laser Lesions in the Central Nervous System of Araneus diadematus Cl.

A laser beam of 6.5-1 joule is directed for 1 msec at dorsalsurfaces of adult female Araneus diadematus Cl. spiders. Thelesion is located by means of histological methods, and relationshipof its position to behavioral consequences—as measuredby changes in the web-pattern—are studied. Twelve animalswith lesions in the area of the supra-esophageal ganglion showdifferent degrees of extensive web-pattern disturbances consistingof smaller and rounder webs with less detail and irregular spacingof threads. Limitations of the method and the role of the supra-esophagealganglion in Araneus as an overall integrating center of sensorymotor coordination in web-building are discussed.