Suppression of pederin biosynthesis through antibiotic elimination of endosymbionts in Paederus sabaeus.

Biosynthesis of the unique defensive compound pederin is confined to female rove beetles of the genus Paederus (Coleoptera: Staphylinidae). These (+)-females endow their eggs with toxin whereas (-)-females, which occur both naturally and in laboratory reared specimens, do not. The latter are aposymbionts lacking biosynthetic capabilities because of endosymbiotic deficiency. They can, however, be induced to accumulate pederin if fed with (+)-eggs during larval development. The endosymbionts can thus be transmitted by ingestion of (+)-Eggs. (+)-eggs treated with benzylpenicillin, erythromycin, oxytetracycline or streptomycin show that the induction of pederin accumulation depends on the antibiotic's spectrum of efficaciousness, its dosage and duration of the treatment. Certain bacteria, probably belonging to the gram-negative type, must be transmitted to produce (+)-females.