Microarray-based genetic identification of beneficial organisms as a new tool for quality control of laboratory cultures

The use of beneficial organisms to help control pests and pathogens in field and greenhouse crops is constantly increasing. Insects and mites are commonly used as beneficial organisms and, nowadays, rearing companies have to produce them in large quantities. Because of the peculiarities of laboratory culture conditions, the quality of lab-reared organisms generally degrades over time. To maintain high fitness levels, cultures are refreshed with field specimens at regular intervals. However, this bears the risk of contaminating laboratory cultures with species or strains other than the intended natural enemy. To ensure that the correct species is produced and also to facilitate surveys after field release, we have developed a diagnostic microarray for identification of beneficial species. Probes have been designed from the different haplotypes of a fragment of the mitochondrial cytochrome oxidase I (COI) gene of each species. Hybridization of labeled PCR amplicons of COI on the microarray chip allows precise identification of 28 economically relevant arthropod species.