Submitted to: International Organization for Mycoplasmology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 11, 1995
Publication Date: N/A
Interpretive Summary: Spiroplasmas are motile, helical bacteria that have no cell wall. As a group, they infect diverse species of insects, ticks, and plants, and are being considered for use in biocontrol. However, determination of the fate of spiroplasmas fed to non-host insects must precede their application for pest management. In the current study, five species of beetle-associated spiroplasmas were fed to adults of two beetle pests: Maladera matrida and Carpophilus humeralis and two species of pest mosquitoes: Aedes aegypti and Culex pipiens. Lack of survival of the spiroplasmas in these test insects suggests that these insects are not suitable hosts. This provides support to the concept that spiroplasmas, if released to control one species of insect, will not harm nontarget organisms.
The study of the fate of spiroplasmas fed to non-host insects must precede any application of the use of these organisms in insect biocontrol. Five spiroplasmas from beetles, the Colorado potato beetle spiroplasma (CPBS), the Cantharis carolinus beetle spiroplasma (CCBS), the Ellychnia beetle spiroplasma (EBS), corn rootworm (Diabrotica) spiroplasma (CRS), and Spiroplasma floricola (the fall flower spiroplasma, originally isolated from the surface of flowers), were provided in the diet to adults of two beetle pests: Maladera matrida and Carpophilus humeralis and to adults of two species of mosquitoes: Aedes aegypti and Culex pipiens. The five spiroplasmas generally were not detected in M. matrida, excluding the CPBS and CRS at Day 1. CPBS and CCBS were detected from all batches of Carpophilus, 1-5 days after feeding, but not after 10 days; S. floricola and CRS persisted for 1 and 2 days, respectively. CPBS was isolated from both species of mosquitoes at 2-3 days, and S. floricola was isolated from A. aegypti (the only mosquito tested), at 2 days post feeding. General lack of persistence of these spiroplasmas in the insects suggests that these insects are not suitable hosts for the spiroplasmas.