Light-Dependent and Independent Responses of Populations of German and Brownbanded Cockroaches (Orthoptera: Blattellidae) to Two Photodynamic Dyes

Abstract

Populations of male German cockroaches, Blattella germanica (L.), and nymphs of brownbanded cockroaches, Supella longipalpa (F.), were confined in the dark and provided only with selected doses of one of two photodynamic dyes. At concentrations > 1 x 10-3 M , erythrosin B caused more mortality in both species than did rose bengal. Most (85%) cockroaches of both species were fed dye within 2.5 h after exposure to light. When German cockroach males were fed rose bengal at 3 x 10-3 M or erythrosin B at 5 x 10-3 M and confined in the dark, significant loss of body weight resulted. Mortality of cockroaches in the dark was delayed, with LT50’s of 106 and 75 h, respectively.