Diagnostic molecular markers to detect and identify primary parasitoids (Hymenoptera: Braconidae) of Ericaphis fimbriata on highbush blueberry

This research provides mitochondrial COI sequences and species-specific reverse primers for Aphidius ericaphidis Pike and Starý, Ephedrus incompletus Provencher, and Praon unicum Smith (Hymenoptera: Braconidae), which are primary parasitoids of Ericaphis fimbriata (Richards) (Hemiptera: Aphididae), an important vector of Blueberry scorch virus (BlScV) on highbush blueberry Vaccinium corymbosum L. (Ericales: Ericaceae) in the Pacific Northwest. The COI sequences are deposited under accession numbers EU574902, EU574904, GU237131, KC211020-211024, KC211027-211032.  The combination of three primers in a multiplex PCR assay detects and differentiates DNA from adults of all three parasitoid species.  When individual field-collected aphids were challenged with the multiplex PCR assay, immatures of the two numerically dominant species, A. ericaphidis and P. unicum , were readily detected as was multiparasitism by these two species.  The uncommon species, E. incompletus , was detected less frequently by multiplex PCR assay than by rearing from the aphid hosts.  The diagnostic molecular markers are useful tools for estimating of rates of parasitism and for identifying immatures of parasitoid species within aphid hosts, particularly if used in combination with rearing and dissection assays of field-collected aphids.